Botany by the Sea

My francophile wife, Lynda, notices every French accent and conversation as we pass by thousands of people shuffling along the cliff tops of Bondi. Me? Well I see a plant motif in nearly every sculpture. Or if not a plant, some incongruous object that will grace a future presentation I give - for example, this first image will become a 'sea horse' in some context.

During my PhD study on algae that produced spores on the top of long straight branches, I used to drive along the Melbourne freeways at night identifying the street lights as one of the algal species, depending on how tall the poles were and how many light fittings they had. Yes one can get obsessed! Still, it's fun and adds a little something extra to life.

But back to Bondi and Sculpture by the Sea, and a few examples from our walk. This next one is obviously a cocolithophorid, a kind of alga covered in ornate umbrellas made of calcium. As it happens the sculpture is modelled on particular species of cocolithophorid, Calcidiscus leptoporus. The real thing is a few micrometres in diameter and floats around in the sea.

No need to point out the botanical connection here.

OK, this one is just a watch. But borrowing from Richard Dawkins and his 'Blind Watchmaker', I'm sure I can find a way to use this in a talk on evoluiton.

Mushrooms, or are they toadstools? In any case, they are more closely related to you and me than to the plants in our botanic garden. Still, we like to include them in our botanical family, just as we do the algae...

I'm sure this will illustrate some conundrum or knotty problem.

I'm always told we need more directional signage in the botanic gardens. Maybe this one will help?

And of course if this was in one of our botanic gardens we'd cover up this chap with a Ficus leaf.

Steamed Weeds

At the Gardens we are always on the look out for weed killing devices that don’t include toxic chemicals. Hot water, or steam, is a good option.

At home I’ve used boiled water from a kettle to kill weeds in the cracks in our concrete path, with varying success. But there are high tech variants of this method available, and we are using one called ‘Weedtechnics’. Sorry to promote one brand, but that’s the one we use.

The idea is to blast the weeds with very hot water, in fact steam - something they don’t particularly like. Basically it cooks them, and in about two days they’ll brown off and die.

Although it uses one of our precious resources, water, it will run on recycled water as well (and we going to install collection tanks in Depot for this purpose). You might also ask about its carbon footprint. On their website, Steamwand boast that this system uses just under 70 kilowatts of energy to heat five litres of water in a few seconds. I’m presuming that is efficient.

The steaming unit sits on a trailer that we can tow behind a ute or tractor and has it's own power supply.

Does it work for us? Senior Horticulturalist Dawson Ougham lists the following benefits in report for our staff newsletter:
• Highly versatile - one machine can perform many tasks
• Vegetation desiccates into the soil improving soil humus
• There are no harmful chemical residues or build up in the soil
• No tillage damage to soil structure
• No root zone damage
• It is safe to use near livestock and waterways
• No risk of spray drift
• Save $ on lost productivity from weather delayed herbicide applications
• Save $ on herbicides
• Accurate programing is achievable for weed control.

Image: At top, horticulturist Adrian Pedra giving weeds hell with hot water. Below, the equipment.

Ancient Australian Fruit*

Coming into bloom in the Royal Botanic Gardens soon is the visually unexciting, but scientifically intriguing, flower of the Nightcap Oak. It has an even more fascinating fruit.

A few months ago the ABC Science page on the web proclaimed 'the critically endangered Nightcap Oak (Eidothea hardeniana)...depends on the forgetfulness of native bush rats'. The rats gather the fruits and hoard them away. Most are eaten but some are overlooked and germinate where the rats leave them.

The fruit looks a little like a walnut inside and has a pedigree taking it back a few million years or so...

For the rest of the Nightcap Oak story, see my earlier posting or listen to my Passion for Plants* chat with Simon Marnie this Saturday, between 9-10 am on 702AM.

Image: Richard Macey's story on Eidothea from the Sydney Morning Herald five years ago. (Sadly Richard retired from the Herald last month.)

River Red Gumlets

The iconic Australian riverbank tree, Eucalyptus camaldulensis, grows in every state and territory in mainland Australia, extending across five million square kilometres of the country. First named from a specimen growing in Italy, Australian botanists have now split the species into seven subgroups.

The species name doesn’t change, as these new subgroups have been given ‘subspecies’ names – all of them shorter, and mostly rolling off the tongue a little easier than camaldulensis!

But before I thrill you with the minutiae of this taxonomic fine-tuning, a little more about the species itself. According to the authors (McDonald, Brooker and Butcher) of this paper in Australian Systematic Botany, the River Red Gum was one the first eucalypts to be grown overseas and is perhaps now the most widely planted of any eucalypt species. Fast growing and tolerant of a wide range of climates and soils, it is particularly good for countries with long dry seasons

The story of how it came to be named from a plant growing in Italy is surprisingly vague. I mentioned in a recent posting that the garden in question was in Camalduli, near Naples, but no know quite knows how the plant got to Italy and fully mature by 1832.

The authors of this recent article speculate that because the species doesn’t grow east of the Great Dividing Range, where the first Europeans settled in 1788, seed was most likely collected on the French expeditions of d’Entrecasteaux or perhaps Baudin. There are historical reports suggesting the seeds came to Italy via France.

But that’s all history. Now there are seven new River Red Gums. As the authors note, the distinguishing characters are relatively subtle and may be difficult to use. Examples are the density of the vein network (reticulation) on the leaves, and the arrangement of the male parts (stamens) in the flower bud. Other characters include the presence and shape of a ‘beak’ on the bud cap, the colour of leaves, and the type of bark

Still, if you live in Victoria the changes are easy – there aren’t any, except for having to add ‘subspecies camaldulensis’ at the end of the name each time you write it down. In New South Wales we have three of the subspecies – Queensland has the most, I think, with four.

In brief, camaldulensis is constrained mostly to the Murray-Darling basin, acuta scattered through Queensland and extending just into the north-east of New South Wales, arida as the name suggests restricted mostly to inland Australia but almost reaching the coast in Western Australia, minima north of Adelaide, simulata the far north of Queensland, obtusa all across the north of Australia, and refulgens in the middle-west of Western Australia.

There are some intergrades between these entities, but that’s partly why they are sub, and not full, species.

Image: One of Murray Fagg's beautiful plant portraits - this is a River Red Gum growing at Coopers Creek near Innamincka in South Australia (from website). I'm assuming it is subspecies arida.

Blue Flowers and Heavy Pods, But This Flower Won't Make You Sad

The Fan Iris, Neomarica caerulea, has fan-like leaves and gorgeous blue flowers. Just what kind of blue I won’t attempt to describe, suffice to note that Simon Goodwin says his photo (top) has been corrected and Simone Cottrell’s (bottom) has not. Simone's was taken with a flash.

Fan Iris grows naturally on coastal sand dunes in Brazil and Paraguay, and luxuriously in the Royal Botanic Gardens in Sydney. You can see it in flower now in one of the ‘traditional’ rectangular beds, between the First Farm and the Wollemi Pine in the roundabout.

This pretty plant is also called the Walking Iris because the mature seed pods are so heavy they droop to the ground, where the seeds can germinate without bothering to spread any further!

Another common name for Neomarica is the Apostle Plant. According to that sometimes quite reliable source of wisdom, Wikepedia, this name derives from the perception that the plant has to have 12 leaves before it flowers.

Whether Fan, Walking or Apostle, it’s an early garden arrival in Australia. According to Historic Houses Trust records, William Macarthur was growing Fan Iris at Camden in the 1840s and 1850s, and he provided material to Elizabeth Park in 1840. By comparison, it didn’t get to California until the end of the nineteenth century.

Nowadays it’s widely cultivated and an iris worth adding to your garden collection. There are a couple of other species in horticulture with varying proportions of white and blue in the flowers.

I'll leave you with a close-up by our third featured photographer, Stephen Bartlett. His picture, I understand, has been corrected for colour...

Palace Pictures From The Oaks to The Gardens

David Thomas showed me a fascinating collection of photographs today. David, who has owned The Oaks Hotel for 35 years, heard me talking on the weekend about the demise of the Garden Palace 127 years ago. As I explained here, the Palace was built in 1879 and burnt down in 1882.

The Oaks began as a pub in 1885 but was totally rebuilt in the 1930s in deco style. It's an intriguing building inside (with a spectacular oak in the court yard), particularly if you wind through the corridors to find the attic store room, as I did this morning.

Four weeks ago David and his son made a decision to remove 15 or so images of the Garden Palace - including its construction, destruction and interiors - from the walls of The Oak. These large (each a metre or more in width) framed prints will be very generously gifted to the Botanic Gardens if we can find a place to display them.

And a place we will find. They tell a fascinating story about the Garden Palace and the Gardens. We'll look into some suitable locations and get them over here and hung as soon as we can. Here's a sneak preview of one of the images - you can see that the displays were very like those in pictures we have of Joseph Maiden's Economic Botany Museum in the Maiden Theatre.

1001 Uses for the Jade Vine

Well just one use really, and a quick posting.

I can't condone such activities in the Tropical Centre at the Royal Botanic Gardens where the Jade Vine (Strongylodon macrobotrys) is now in spectacular flower, but...you might look on the ground for a few flowers...

This picture was taken in Dalat, in central Vietnam.

Prize-winning Young Horticulturalist to Dress Drab Buildings

I was lucky enough to attend the inaugural Young Horticulturalist of the Year for New South Wales lunch and announcement. And the winner was…Matt Donaldson, the owner of a landscape and property maintenance business called Green Acres.

His horticultural passion is greening vertical walls, or as he puts it “put[ting] a new spin on landscaping facades and walls …dressing up drab buildings, making a more pleasant workplace and streetscape [by] greening concrete jungles”.

I’ve included below a slightly edited report from horticultural journalist and television star Ally Jackson’s report on this great initiative by the Australian Institute for Horticulture. And by the way, congratulations to all four finalists, particularly our very own Julie Cooper!

Image: Les Halles in Avignon, France – the work of vertical wall pioneer Patrick Blanc.

Young Horticulturist of the Year Award 2009

“The inaugural Young Horticulturist of the Year Award has just been garnered on Matthew Donaldson for his innovative plans to create a living wall on the Hawkesbury Regional Museum. The $10,000 prize had encouraged many fledgling horticulturists to apply, with four entries truly standing out.

“The prize is open to horticulturalist in their last year or recently graduated from TAFE. Offering the richest award to horticulturists under 35, the state competition is open to those studying any form of amenity horticulture, including nursery production, retail nursery, landscape construction and management, aboriculture, natural area restoration, turf management and parks and gardens.

“The finalists appeared before an industry panel of Brendan Moar (Lifestyle’s Dry Spell Gardening), Graham Ross (Better Homes and Gardens) and Yates’ Judy Horton.

“Julie Cooper is a 4th year apprentice at Sydney’s Royal Botanic Gardens. Her project involved creating a collection of postcards depicting the plant collection of the gardens. Giving the visiting public an “insiders view into how a garden is born, grows, evolves, matures and changes due to environmental cycles and seasons”. An artist also, Julie would use her talent as a photographer to capture the beauty of nature and the cycles of plants, seeing the postcards as an extension of the gardens themselves, “a way to communicate beyond the garden walls, what is happening within…A tool to reconnect people with the environment”.

“Lilly van Epen is a horticulturist and garden designer-in-training. Her enthusiasm for horticulture is contagious and her drive and ambition will take her a long way. Lilly’s proposal for YHOY was to develop and expand the horticultural knowledge and understanding of primary school-aged children. A program is already underway at Marsfields’ Kent Road Public, which involves kids in 3- 6 class. Lilly’s proposal differed from other school gardens as she intends to implement “structured horticultural lessons that will encourage students to develop a symbiotic relationship with their natural environment”.

“Nathan Burke is a Permaculture garden designer, he volunteers at Moss Vale’s community garden and Harmony community farm and is a member of the Southern Highlands Seedsavers Network. His project was borne out of volunteer work with the St Thomas Aquinas Primary School food garden. As project designer and facilitator of the permaculture food garden he said, “I especially felt that creating a school garden would be an excellent way to teach children the value of food as well as showing them how fruit and vegetables can be produced sustainably and ecologically without straining or damaging the environment, but actually enhancing and enriching it”. Nathan’s garden design has inspired the kids in the school to become active, responsible gardeners, nurturing and growing their passions for gardening.

“Matt Donaldson runs his own Landscape and property maintenance business called Green Acres. He has a vested interest in vertical gardens, has registered the name ‘Living Walls’, and since being announced the winner, is well on his way to greening vertical spaces -initially in the Hawkesbury region. His project involves building a living green wall at the Hawkesbury Regional Museum, depicting the logo of the museum. Matt wants to “put a new spin on landscaping facades and walls …dressing up drab buildings, making a more pleasant workplace and streetscape [by] greening concrete jungles”.

“Having won some media training as well as the prize money, expect to see more of the inaugural winner of 2009’s award, Matt Donaldson. And for years to come, we will welcome the input of other young, inspired horticulturists who walk away winners of the Young Horticuturalist of the Year award. It’s a very exciting time to be in horticulture.”

Ally Jackson, Australian Insitute of Horticulture, 23 October 2009

New Leafless Peas

Here we go - deep breath - some taxonomy... The latest issue of the scientific journal Telopea* (volume 12, number 3) includes papers on eucalypts, peas, mosses, trigger plants (Stylidium), the ‘restios’, cycads in Indonesia, the sea-grass Zostera, native nightshades and a wild rice.

Lots of ground covered, from new tribes and subfamilies of Restionaceae, to linking ‘type specimens’ to some species of Eucalyptus. For New South Wales, there is a new species of Solanum from the mid north-coast, and a new name for a common Zostera in the intertidal east coast.

Four new species are described in the pea genus Bossiaea, with a key to all the species in this genus without leaves and with small flower scales (bracteoles) that fall off early.

Before this paper everything that fitted the above description was called Bossiaea bracteosa. That name now only applies to plants growing in subalpine areas of Victoria, the ones with prominent leaf scales with a heart-shaped base and distinct veins.

Plants growing along the Shoalhaven River near Braidwood are now Bossiaea bombayensis, from the banks of the Murrumbidgee River and its tributaries in ACT Bossiaea grayi, from the Abercrombie karst area south of Bathurst Bossiaea fragrans, and from the Brogo River catchment near Bega Bossiaea milesiae.

The differences are all to do with the flower size, structure and colour, as well as features of the green flattened stem (the cladode).

Bossiaea bracteosa was considered rare in New South Wales. The new species range from restricted and locally abundant, to under threat of extinction (in one case the remaining 20 plants are being grazed by goats and facing competition from Serrated Tussock grass).

:) These are ‘good’ name changes, where were learn a little more about the plants and their diversity.

*Journal issue will be loaded onto this site shortly. Image: One of the new Bossiaea species - this one was growing in the Australian National Botanic Gardens, taken by Murray Fagg (photo No.: dig.5200).

Selfwatering Plants?

Rain brewing over the Opera House, taken from the Sydney Harbour Bridge while on the Seven Bridges Walk today. Yes it did rain, and should I blame the plants in the botanic gardens behind this music hall?

In short, and oversimplifying things awfully, some plants have the ability to water themselves!Jonathan Garner, landscape gardener and councillor of the Australia Insitute of Horticulture, sent around this fascinating story about plants, bacteria and rainfall.

Better let Jonathan tell the story.... He says: "I was listening to an amazing bbc documentary about bio precipitation and the role bacteria’s play in weather. The practice of cloud seeding with certain elements has been popular for quite some time. A fella by the name of David Sands from Montana university proposed the concept of cloud seeding with bacteria in the late 1980’s. Since then ski resorts have been utilising bacteria to initiate snowfalls.

"The fascinating thing is that this bacteria Pseudomonas syringae and its many pathovars finds nourishment and as such undergoes accelerated cell division (procreation) on the leaves of plants. Why? and How?

"Well. Pseudomonas is extremely effective at making water freeeeeeeze (ice nucleator). It has a protein that makes water molecules stick together at warmer temperatures. In fresh water, without a catalyst to make water molecules stop moving around so quickly to begin the process of becoming a solid, the temperature required is -40c ish. The freaky thing is Pseudomonas initiates ice nucleisation at temps of 0c - -5c.

"Why does it breed on leaf lamina? I’m glad you asked. Pseudomonas initiates frost at warmer temperatures. When ice forms on foliage, the jagged sharp ice crystals penetrate the leaf lamina and as such provide easy access for pseudomonas to dine on the plant without having to personally invade the plants outer defences. It also side steps the plants natural reaction of developing phytotoxins or defense mechanisms when attacked by a parasite. The downside is that pseudomonas is responsible for types of cankers and other plant diseases. The upside is that pseudomonas syringae is being trialled for its effectiveness at controlling fungal decay during storage of fruits and vegetables.

"Back to its ability to initiate freezing process. It’s common knowledge that in order for rain to fall, the water molecules in the clouds need to cling together (freeze) so that gravity can bring it down here as rain. Well. The funky thing is that during spring and summer when transpiration is in full swing, the Pseudomonas enter the atmosphere via air movement & as hitchhikers within water vapour during transpiration. So the huge populations of pseudomonas that have bred on the foliage & fed on plant material by making water freeze on the foliage to access an easy meal, float up into the atmosphere and initiate precipitation for the plants to take advantage of.

"The interesting thing is that science has discovered that certain varieties of crop have the knack of hosting massive populations of Pseudomonas compared to other varieties within the same species. Certain cultivars of barley for instance. With this knowledge in hand, plant breeders will be able to cross these strains with other strains to create cereal crops that will allow more of these cloud seeding critters into the atmosphere and as such improve the necessary initiation of ice crystals at warmer temperatures bringing the opportunity of a natural process of cloud seeding.

"To take things another step further. It isn’t often that nature allows a forest full of diverse plant life to die from drought. It would seem that we are getting closer to having the factual proof that areas with high quantity of vegetation actually create the rain required for the cycle to continue."

Thanks Jonathan!

Remembering the Palace*

It is just over 130 years since the giant Garden Palace was opened in Sydney, on 17 September 1879. And a little more over 127 years since it burnt down, on 22 September 1882.

The Palace lasted less than three years but it won’t be forgotten. Designed by Colonial Architect, James Barnett, it was home to the Great International Exhibition of Sydney.

England had built the Crystal Palace for its Great Exhibition in 1851 – botanic gardens historian Ed Wilson says Joseph Paxton was inspired by the veins on the giant Amazon Lily (Victoria amazonica) to create the supporting metal structure for that particular building.

The Garden Palace in Sydney was built of timber and corrugated iron, and never envisaged as a permanent structure. It was 244 metres long and extended from the State Library of New South Wales to the Conservatorium of Music, occupying the whole south-west corner of the present-day Royal Botanic Gardens. It was a little like the Exhibition Building in Melbourne, but even bigger and with numerous towers and ornaments.

The fire is assumed to have been started deliberately, possibly by local residents whose views were blocked by this massive building (trees are killed today for similar reasons), or to destroy the 1881 census which revealed convict ancestries (at that time an unpopular heritage).

Lost in the fire were lots of colonial records, statues, paintings, books and various exhibits. Without the fire the Palace may have been used for public meetings and concerts for a few more years, and the geological exhibits and government archives would have been saved, but it’s unlikely it would have been still standing today.

Today you can visit the Memorial Garden to Pioneers, a ‘sunken garden’ honouring the men and women of the early colony, and built at the centre of where the main dome of the Garden Palace once stood.

The Four Seasons statues, flanking the main stairs leading down from the Conservatorium Gate into the centre of the Gardens, also provide a link to the Garden Palace, but only just!

The original four marble sculptures were imported from Italy in 1879, probably produced under the direction of Charles Francis Summers (son of a more famous sculptor Charles Summers). During or soon after the Garden Palace fire, Spring and Autumn were damaged.

In more recent times, Winter was in storage for few decades but restored and reinstated two years ago.

The current Spring was a replacement donated to the Gardens in 1957. It lost an arm again during the Sydney Olympics, which was replaced but is missing, again. Autumn is a replacement from 1883.

And Summer? There is no Summer, by Summers or anyone else. It was severely damaged by vandals around 1970 and we have two pieces of torso in storage but no head (there was a second Summer but we only have its head, and it doesn’t match the torso pieces).

I’d like a ‘Sprinter’ and ‘Sprummer’ as well, to go with my proposed new seasons, but let’s not go there today…

Image: This ‘spring’ sculpture in the Royal Botanic Gardens replaces one damaged around the time of the Garden Palace fire.

*This Passion for Plants posting will also appear on the ABC Sydney website (possibly under 'gardening'), and is the gist of my radio interview with Simon Marnie on Saturday Morning sometime between 9-10 am on 702AM.

Sausage Tree needs Bats and Elephants

A lot of flowers are brightly coloured and scented, usually to attract birds, bees and that kind of thing. Most of the activity occurs during the day, with some flowers closing at night to avoid any further damage to their precious blooms.

But there are flowers designed for night time display. We have the Sausage Tree in flower right now, just south of the Henry Lawson gate. Its flowers are one of the more dramatic night-time offerings.

Kigelia pinnata, as it is called botanically, is a relative of the Jacaranda. Both are in the family Bignoniaceae with other garden plants like Wonga Vine (Pandorea), Cape Honeysuckle (Tecoma) and Indian Bean (Catalpa). They all have ‘foxglove’-like flowers, but are unrelated to Foxgloves…

As you can see in the picture, the Sausage Tree has a hanging group of flowers designed for bat pollination. The flowers are dark-blood coloured and smell offensive – the sort of thing big bats like. In their native habitat, but less commonly in the Royal Botanic Gardens, the large sausage-shaped fruits are eaten by rhinos and elephants, presumably spreading the seed far and wide.

As I wrote in Nature Australia a few years back (spring 2002): “Sweet-smelling, light-coloured flowers, often white or pale yellow and easily visible in the evening gloom, attract nocturnal insects. Moths hover over the flowers and, because they don’t need any platform to land on, these night bloomers often have neat, regular flowers. Jasmines, the so-called Night-scented Jasmine (Celestrum nocturnum), gardenias and the aptly named Moonflower (Ipomoea alba) are examples of this moth-pollinated clan.

“Another band of flowers emits a musty or rank odour at night. They are dingy in colour (greenish-yellow, brownish or purple) and often have dangly bits attached to the petals or other flower parts. They are the bat-attracters. Bats like something to hang onto—the dangly bits—and preferably with the flowers facing the right way—that’s upside down to us.

Look at the flowers of some of the tropical and subtropical garden plants such as the Sausage Tree (Kigelia pinnata), bananas, Cup of Gold (Solandra maxima), and the fantastically named Midnight Horror (Oroxylon indicum). A recent study revealed that some plants are even ‘loud’ to bats (see “Noisy Flowers”, Nature Australia Autumn 2000). The flower of Mucuna holtonii, a Central American vine, acts like a sound-reflecting mirror and draws bats to it. If the distinctive concave petal is removed, the flower cannot echo ultrasonic signals and remains unpollinated.

“Closer to home, flying-foxes pollinate or spread the seed of many Australian rainforest trees, undoubtedly playing a key role in the regeneration of some rainforest remnants. Eucalypts in these areas often have light-coloured flowers and produce more nectar at night apparently to attract these nocturnal visitors. Gliding and tree-climbing marsupials, with relatively poor vision but a well-developed sense of smell, are also active at night, but their role in dispersing the seeds of strong-smelling, dull-coloured fruits is unclear.”

So take a look at our Sausage Tree. Enjoy the flowers now and the sausage-shaped fruits in summer.

Round and Red

As Patron of the Cacti and Succulent Society of New South Wales, it is always a pleasure to feature a cactus here. This week it’s the intense red flowers of the rare (in nature) Echinopsis formosa.

This globular cactus is growing just outside the entrance of the Cacti & Succulent Garden. It’s not that it isn’t welcome inside the fence, just that it has particular relevance to our Rare and Threatened Garden theme in the neighbouring beds – this species is at risk of extinction in the wild due to over collecting by cacti and succulent fanciers.

It used to be called Soehrensia formosa. Soehrensia was a genus of about 10 species from Argentina and Bolivia, and this particular one grows in the north-west of Argentina.

I should note there is some disagreement and inconsistency in the names used for this cactus and I notice that Trichocereus formosus is a name also cited in a list of potentially weedy species for Australia. By the way, although a plant can be rare in its natural habitat and a weed somewhere else, the listing doesn’t seem to be suggesting it is a weed (yet?) in Australia. Just one to watch.

If we accept Echinopsis, this is a largish genus of about 120 species, often called the Sea Urchin, Easter Lily or Hedgehog cacti. Echinopsis formosa itself is called Koko or Pasakana locally, if you live in Argentina I think.

Even in this picture taken by Simon Goodwin last week the flowers are well advanced, and I couldn’t see any new buds when I walked past this morning. But the intense red flowers will be around for this week at least. Here it is close up of the bloom, again care of Simon's camera:

Slow Food, Slow Gardening

Here is Costa, of Costa's Garden Odyssey on SBS TV, handing out some emu 'prosciutto' at the Royal Botanic Gardens in Sydney, while 100 or so of us eat and listening to people talk about food - slow food, and bush food. I've posted a few more pictures at the end.

Costa was filming as part of a future episode on the botanic gardens and bush food. While we ate, and were filmed, we heard:
· Alison Drover, from Slow Food Sydney

. Jean Paul Bruneteau on (cooked) kangaroo, warrigal greens, and other delightful Australian foods. Jean Paul designed and created the meal with the help of lots of Slow Food volunteers.

· Carlo Petrini (described by the UK Guardian as one of the 50 people who could save the planet) on the slow food movement and its similarity to some of the philosophies of Aboriginal culture.
· and our very own Clarence Slockee MCing, chatting about this and that, and discussing the finer points of bush foods and local plants.

We were didn't quite hear Lynne Ziehlke on Hawaii’s – sorry Australia’s – macadamias, and Michael Klausen on his ‘indignosu loaf’ ( a bread made especially for the event from fermented seed) but both products were warmly appreciated.

And of course we ate the subject matter. The lunch was the Botanic Gardens Trust’s small contribution to Crave and the Sydney International Food Festival. Dipping our toe in before we dive in head first next year, perhaps! Anyway, a big success – tasty conversation and food. The weather was a little less than perfect but that's the way it goes.

What does this have to do with plants? Well apart from it being held in the botanic gardens, I said something along and very like the following lines...

"It's entirely appropriate to eat in the gardens. Life, and food, depend on plants. Plants get the energy from the sun and we either eat them or something that ate them first.

"Slow food also fits perfectly with our approach to gardening. Not that we don’t work hard, but gardens take a long time to grow. This one - 193 years, so far… Plant small trees, watch them grow (and they will become better established, safer and longer-living) and treat garden as changing environment, not an instant product.

"And do plant things you like. It’s also appropriate to serve local food, bush food… We encourage growing local plants in your garden, or plants that won’t harm the local environment. - three rules for gardens - no toxic chemicals to survive, not escape into bush, (usually) low water.

"Carlo Petrini and the Slow Foot movement stress that food should be good, clean and fair. We believe gardens should be very good, they should not harm the environment and plant growers and our horticulturalists should get fair compensation for their work!"

Pink Figs - But Only For a Short Time!

Simon Goodwin, who took this shot of our pink-leaved fig against the Sydney backdrop on Friday, says the spectacular colour will last only a few days.

I'll take a look tomorrow morning - on my leisurely way to the ‘Slow Food Bush Tucker Picnic’ in the Royal Botanic Gardens (which I’ll post about a little later) - but thought I better post this post haste.

The fig in question is called Ficus sur, from tropical and southern Africa and a few nearby islands. It was once known as Ficus capensis, a reference to its presence on the southern Cape, and Sur is a region in Ethiopia.

Its common name is the Broom Cluster Fig, a reference to the bunches of fruits borne along the stem and apparently sometimes even arising out of the ground from roots.

Ficus sur is one of the ‘non-autumn’ deciduous trees I talked about previously, and following a few leafless weeks it’s about to return to full foliage. But first we get this colourful display captured by Simon.

That You Bro?

Plants are as hip and cool as animals. It goes without saying really. We now know that at least some plants can recognise their brothers and sisters, and it might be worth planting siblings together for a mass flower show.

We already knew plants moved (albeit usually a little slower than most animals and usually attached at one end), reproduced (that’s what flowers are for!), counted (sort of, and only up to two…the Venus Fly Trap responds to the second contact with one of its sensitive hairs…) and communicated with each other.

It’s been long known, for example, that plants communicate through releasing chemicals that are toxic to other species, and through various colours and displays to attract pollinators and seed dispersers.

Some intriguing research from the University of Deleware, in the US, found that plants can also recognise their brothers and sisters. They started work on a plant called the Sea Rocket (Cakile – a common weed on Australian shores). When you grow seed from the one batch together, the siblings don’t send out roots to compete with each other.

If you throw in seed from a different parent, it each seedling for itself!

This they found out in 2007. The next step was to find out how a plant could do this. Except for potatoes and corn, they don’t have eyes or ears (sorry).

For this work they turned to the fruit-fly of the plant world, Arabidopsis – actually a close relative of the Sea Rocket (they are in same ‘plant family’).

The researchers collected wild plants to avoid contamination of their study plants from various close and distant relatives of the laboratory-bred forms.

Turns out the roots secrete a chemical that encourages root growth in ‘strangers’ and discourages it in siblings. The signal was jammed by the addition of a chemical that blocks roots secretions.

It’s not clear to me whether the signal chemical inhibits or encourages growth, or both. It’s all relative I guess.

The siblings also grew more strongly above the ground, at least in the seedling stage, because they spent less energy on root growth. They also tended to have shallower roots.

The research has implications in agriculture and horticulture, wherever we have a single species grown en masse – a monoculture. In our home gardens, maybe we could get plants to grow better together if they are all from the same parent.

Image: Seedlings of Wollemi Pine at Mount Annan Botanic Garden, perhaps desperately trying to communicate with each other...

The Good, The Bad and The Ugly

Do you want to know the new name for a familiar plant, and why it’s changed? Today I was urged to promote and explain the changes to plant names that irritate and frustrate everyone. Or indeed, those that don’t. To be fair to Richard May, NSW State President of the Australian Institute of Horticulture, he said someone should do it, not that I should head home and hit the blog!

I’d be curious to hear whether this is general desire or not. It’s important and useful to use the correct botanical name, but would it make interesting reading? A few years back (last century…) I wrote a short series of articles in the Victorian Naturalist and then Society for Growing Australian Plants Victoria Newsletter, explaining the changes to plant names in Victoria.

As a start, below is the abstract of the talk I gave to the national Australian Plants Society meeting in Geelong a few weeks ago. It gives a sense of the approach I would take. I’d try and make it clear when a change is a good thing (not necessary easy or liked, but reflecting new scientific knowledge), an ugly thing (when for consistency and to solve arguments, the rules of plant naming mean we should use an alternative name) or a bad thing (when the change isn’t really necessary and causes unnecessary pain, or is contrary to good science). In most cases the taxonomic experts won’t accept a ‘bad thing’ but for a variety of reasons it may be necessary or preferable in some cases.

As to whether I have time to chase up the details or can keep track of the important ones, that’s another question. And I would continue to populate the blog with other bits and pieces of botanical trivia. But firstly, is there an interest?

THOSE NAME CHANGES (Abstract)

Generally in life we embrace new knowledge and welcome scientific discoveries. We learn more about the world around us, and live a healthier and happier life. But when scientists change the names of plants, we don’t always see this as reflecting good science. That’s because some name changes are more about book keeping than braving new frontiers. The system we use today for naming living organisms started in the eighteenth century with Carl Linnaeus, but the rules of nomenclature have evolved over time. So too has our knowledge of the living world – for example, Carl Linneaus was unaware that to an order of magnitude, live is unicellular.

I’ve always thought there are three kinds of name changes – the good, the bad and the ugly. All are necessary but some are more satisfying than others. Ugly is when we discover an older name that has fallen out of use and resurrect it. Following the rules of nomenclature we have to use the oldest name but often there isn’t much extra information in the change. Bad is where a name change is made for legitimate scientific reasons but we don’t have to make the change and we don’t get much or any new information content. The good? This is where we move from a flat to a spherical earth. The new name and classification better explains the world around us and allows us to predict new things about that world.

Remember that a scientific name (representing a taxonomic group) is always a hypothesis, and it should change or be rejected as more information becomes available. Each name is a reference point only – all life is interconnected, evolving and adapting – and our nomenclature and classifications are crude systems to make sense of this wonderful diversity.

Blood Orchid

I like to call this the Blood Spider Orchid, although that name is also used for a Western Australian species of similar hue. This one definitely has a dried blood or burnt red colour, and we always like to make orchids sound a little macabre. It smells, purportedly, like a hot motor.

Although we’ve left the Grampians, I did say we were travelling to Castlemaine, which is also good goldfields orchid country. Except for this blood orchid, better known as the Crimson Spider Orchid, the species are the same as we saw in further west.

Caladenia concolor grows sporadically around Victoria, and also into southern New South Wales where it’s only known today from granite country near Albury. My colleague there, Paul Scannell from Albury Botanic Gardens, is working on saving this endangered population.

In Victoria, it is apparently more common around Beechworth and Chiltern. There is a population near Violet Town (where I used to travel to as a kid from Euroa to go swimming) down to about four individuals and with a few distinctive characteristics.

The Castlemaine one is found in box ironbark forests in a couple of places around the town. There are only a handful of individuals in each population and weeds and passing foot damage are probably the biggest threats. The ‘midlands’ variant has also been mooted as a distinct species but I’m not sure of its current status. I should check the latest edition of the Victorian orchid book by Jeff Jeanes and Gary Backhouse...

My picture show a plant a little past their prime, but still picturesque (for an orchid lover). It’s becoming well known around the town and I even saw postcards of it for sale at the (locally famous) Wesley Hill Market.

The Season of Petyan, in Gariwerd

That’s it for Gariwerd, or the Grampians, in the local season of ‘petyan’ (close to my sprummer). Tomorrow it’s off to more goldfields country, in Castlemaine, but for socialising rather than botanising. I’ll ease off on the blogging too!

I thought I’d leave with a view from Mount William, a Gang Gang Cockatoo we saw there, and the State Floral Emblem, Epacris impressa. Lynda tells me that the name ‘impressa’ refers to the dimples at the base of the flora tube – clearly visible in this picture. Sounds good to me.

So to Gariwerd. The Jardwadjali and Djab Warrung people have lived in this area for thousands of years and I gather both recognised six seasons. Each season is about two months long, responding to changes in the activities of local animals and plants. Nesting birds, yam harvesting, butterflies, eel hunting, honey bees and cockatoos are important indicators.

I was thrilled to see an early spring, ‘larneuk’, starting in late July and running through to August. Although defined as the season of nesting birds, wattle and orchid flowering is mentioned as characteristic. While I like an August-September ‘early spring’ (sprinter) this is exactly the kind of environmental change we should be reflecting in what ever seasonal system we decide to follow.

There are plenty of plant indicators in Gariwerd. About 970 species of plant grow and flower here, of which 20 grow no where else. The spring wildflowers are justly famous. At the moment swathes of Calytrix, Micromyrtus and Thryptomene mark the roadsides.

And did I mention orchids? I’m not sure how many there are in the Grampians, but well over 100 species, all of them terrestrial (or ground) orchids. We saw plenty more today, including fields of the pretty spider orchid Caladenia versicolor, and what ever green comb they were cohabitating with. Donkey orchids (Diuris) are everywhere, with a new record for the trip, Diuris orientis, spotted a few times.

I’ll close with a picture of this species, commonly called the Wallflower Orchid, and previously known as Diuris corymbosa. Like many orchids, its name has changed to reflect our increase in knowledge about these plants. Sometimes the changes are informative and robust, other times less so. In any case, this orchid is widespread in south-eastern Australia, and like many of the donkey orchids looks so coy with its legs (lateral sepals) crossed.

Australian Garden of the Royal Mail Hotel, Dunkeld

Most visitors to the Royal Mail Hotel in Dunkeld, at the southern end of the Grampians in Victoria, are after fantastic food. It’s highly regarded as one of the best country restaurants in Victoria, indeed one of the best restaurants in the State.

The really top class meals are served only in the evening (and at a ‘special occasion’ price) but we enjoyed a similar quality bistro meal on a break from orchid twitching. It’s a good place for plant lovers (who like to eat well) because local garden designer and plant grower Neil Marriott has planned and planted the garden.

I gather Neil has been brought in recently to resuscitate a garden succumbing to the long Victorian drought. Some of the key elements have remained – e.g. neat rows of native grasses in the foreground of Mount Abrupt – but lots of spectacular Western Australian species have been added.

It really is a beautiful garden and one that matches the local stone walls and stone mountain backdrop. Neil spoke about this garden at the Australian Plants Society meeting in Geelong last week and emphasised the importance of not allowing plants to become dependent on regular watering.

Some of the original plants should have survived but probably had their roots too close to the surface and were unable to cope when the drip water system was turned off. The new plants, Neil hopes, will adapt better.

Of course after the lunch, and today, we (Lynda and me) have continued to seek out orchids (and other flowers, but it’s true that orchids have dominated) across the Grampians. Today I can add to the list:

Pterostylis pedunculata
Pterostylis planulata
Cyrtostylis reniformis

I’ll include here at the end a flowering stalk of the intriguing Pterostylis planulata, also called the Flat Rustyhood – it’s one of the greenhoods in the ‘rufa’ group that tend to bloom in the warmer months. They also have withered leaves at flowering and various other fascinating floral characteristics, but that’s enough botany. Visit the Royal Mail Hotel to eat (and stay), and enjoy the garden and the nearby wildflowers.

More Orchid Twitching

Today five new additions to the list of orchids sighted (and enjoyed) at the Grampians. Three of them are illustrated singly above, as well as a field of Golden Cowslips (Diuris behrii) and a clump of Musky Caps (Caladenia gracilis)

The three new ones illustrated are:
Caladenia reticulata – reddish flower with narrow teeth at edge of ‘lip’
Caladenia clavigera – flower with wavy lip edge and blob of red-black
Caladenia venusta – illustrated above, mostly white and with floppy ‘arms’

Also recorded (and photographed but not posted ) were:
Caladenia iridescens
Pterostylis ‘macilenta’ (a leafy greenhood restricted to Grampians)

The rules of orchid twitching – made up as we go along – are no leaves without flowers buds that aren’t at least a little bit open. The latter category is for sun orchids. We’ve seen a couple of Thelymitra species in bud that will probably open in the next week or two but these have been excluded from the list – even when we can guess or confirm identification from what we see.

We’ve also excluded anything recognisable by the leaf, but not in flower. We haven’t recorded, for example, Red Beaks or Undertaker Orchid (Pyrorchis [once Lyperanthus] nigricans) whose fleshy leaves are a common sight in recently burnt areas.

In case you are interested, I’m taking a more traditional approach to the generic classification. In particular, I’m not splitting up Caladenia – this approach is acceptable and is in line with most of the herbaria and botanic gardens around Australia.

Other genera may well warrant splitting (e.g. the greenhoods, Pterostylis) but for now I’m sticking with what I know and what isn’t wildly incorrect in good taxonomy. Good taxonomy, to me, is each group including all the descendents of a common ancestor, and minimising taxonomic change.

Orchid Twitching

That’s twitching, not tweeting, but it amounts to the same. The scientific name of each orchid is a kind of tweet – an informative, less-than-140-character summary of what’s up.

I’m in the Grampians and looking out for terrestrial orchids. This is a great place for these small but quite exquisite plants. They usually have a single leaf and produce a flower stalk that last a few weeks each year. Most of the time they exist simply as an underground tuber.

So today I visited various roadsides and reserves in the northern Grampians, from Wartook to Stawell. As always, some spectacular finds and some irritating illusive species.

I know they are just names (20 today…), but if you know some of these you’ll realise how much fun it was to find them. And then there are the elaborate pollination strategies of deception and fraud…

Caladenia carnea
Caladenia cucullata
Caladenia gracilis
Caladenia ornata, I think
Caladenia parva, I think
Caladenia phaeoclavia
Caladenia tentaculata
Caladenia versicolor
Diuris behrii
Diuris chryseopsis, possibly
Diuris pardina
Glossodia major
Prasophyllum (two species, but too hard to identify!)
Pterostylis nana
Pterostylis nutans
Thelymitra antennifera
Thelymitra megcalyptra
Thelymitra nuda, I think
Thelymitra pauciflora
Thelymitra Xmacmillanii

I’ve included just a few pictures here and I’ll probably post some more later. Although orchids are abundant in the northern Grampians, telecommunication signals are a little harder to locate.

Images, in order from the top: a field of green combs; three of the similar green comb species – Caladenia tentaculata, Caladenia phaeoclavia and Caladenia parva; a spider orchid – Caladenia versicolor; a field of sun orchids (mostly the blue Thelymitra megcalyptra but with a few of the pink Thelymitra Xmacmillanii); and finally just one of the sun orchids – Thelymitra Xmacmillanii.

60% Aussie Trees in Botanic Gardens*

Earlier this week I was intrigued to hear Richard Barley (Divisional Director at the Royal Botanic Gardens in Melbourne) make the same comment about Melbourne Gardens as I make about our Sydney Gardens.

It’s a favourite gripe of mine (and his) that visitors to the Royal Botanic Gardens and Domain don’t see the ‘Australian plants’. They are looking for red dirt and desert wildflowers, or gum trees, but don’t notice the magnificent rainforest trees through the garden.

In fact 60% of our trees are native to Australia! (BTW 33% of the actual species are native - i.e. we have lots of Forest Red Gums, and Port Jackson and Moreton Bay Figs.)

A recent example of Australian-tree-blindness was Monty Don on his tour around the world in 80 gardens (on ABC TV earlier this year). He saw the flying foxes but didn't recognise the Aussie trees - or many trees at all it seems.

There are a few key Australian locations that feature in the collection. The first head of the Botanic Gardens, Charles Fraser, collected plants from near Parramatta in 1822, including most probably a seedling of the Red Cedar (Toona ciliata) growing near the Palm House.

We know this because the King’s Botanist (employed by Joseph Banks), Alan Cunningham, met the Government Botanist (the first to hold this title), Charles Fraser, at Parramatta and was envious that he had a cart and two horses.

Then there was the Oxley Expedition to the Brisbane and Logan Rivers in 1828, which included a Flindersia and Melaleuca which I’ve also spoken about before.

Then there are trees from New Caledonia, not quite Australia, but certainly part of our local region. Director Charles Moore collected there in 1850, although he relied to some extent on locals collecting material for him.

The Atherton Tableland features strongly, as it should. This region is home to what is called the Mabi Forest – ‘mabi’ comes from the local Aboriginal name for a tree kangaroo that lives there.

A dozen or so plants in this habitat are under threat, including the Tree Warratah (Alloxylon flammeum) which grows beautifully in Sydney gardens and streets. The Rose Silky Oak (Darlingia ferruginea) is another showy flowering tree from Atherton that does well here in Sydney.

The Macadamia (Macadamia tetraphylla) is from another rainforest hotspot, the south-eastern corner of Queensland and north-eastern tip of New South Wales. The Royal Botanic Gardens specimen is spectacular when covered in the pink to mauve flower sprays.

Another good looking tree from this region is the Tulipwood (Harpullia pendula). There’s a lovely old specimen near the Maiden Pavilion. The flowers are small and non-descript, but the showy fruits have two large lobes and are bright orange. When they dry out and break open you’ll see shiny black seeds. Tulipwood is popular as a street tree in Brisbane but not so widely planted in Sydney. (The wood is highly valued, although there seem to be other species called Tulipwood in the trade, so beware.)

There are plenty more Australian and local region rainforest trees in the Royal Botanic Gardens. Next time you are walking through, look for the labels that identify some of our biggest trees. Or if you are feeling lazy, wander through the Australian Rainforest Bed between the Palm Grove and the Tropical Centre, which contains pretty much only species from rainforests of eastern Australia, from the tropics right down to the temperate climes of Victoria and Tasmania.

Images: The Tulipwood is great looking 'atypical' Australia tree with colourful fruits.

*This Passion for Plants posting will also appear on the ABC Sydney website (possibly under 'gardening'), and is the gist of my radio interview with Simon Marnie on Saturday Morning (this week or next...) sometime between 9-10 am on 702AM.

Leafless in Melbourne (and Sydney)

I'll explain the significance of this Sydney 'autumn tree' in due season, but I took a walk in the Royal Botanic Gardens in Melbourne yesterday. Very beautiful, as always, but also a little stressed. The rain that kept me out of the rivers wasn't enough to hide the effects of a long drought. The trees particularly were doing it tough.

That said, you have to be careful this time of year. Plenty of plants lose their leaves in 'late sprinter', something I mentioned in passing a while ago (see shedding-leaves). Mainly it's to get rid of damaged and battered leaves, as well as some of the pests that go with them, and replace them with fresh foliage.

Many of the species are tropical, with leaf drop occurring in the dry season to help retain water and save energy. Just about any tree will drop some leaves during drought.

The Melbourne Gardens has a great collection of conifers, dating back to the great botanist Ferdinand von Mueller, and the Taxodium species have shed their leaves as they do each year. The figs are either doing the same (e.g. the White Fig, Ficus virens, from northern NSW up into Asia) or looking a little worse for wear.

Back in Sydney, the (four) leaves on my four-year old Barringtonia neo-caledonica at home are a deep claret - or is it burgundy or shiraz - red. Luckily Simon Goodwin has come to the rescue with a picture of a specimen doing much better in the Royal Botanic Gardens (see above).

And there are others around the Domain and Royal Botanic Gardens in Sydney. In addition to the White Fig, there's the aptly named Deciduous Fig, Ficus superba, native from Nowra northwards into Asia, but with the variant called henneana known only from Australia.

It's not just trees from Australia or nearby islands. The beautiful Ficus vogelii from tropical West Africa is leafless as we blog. Our Red Cedar (Toona ciliata) collected from Parramatta 180 years ago is desperately trying to produce new leaves as the flying-foxes snap shoots and damage growing tips, while a Chinese species, Toona sinensis, is I think 'naturally' without leaves in late sprinter.

Yes the Melbourne Gardens are suffering, but trees know the best way to deal with hardship is to shut down and drop out.

Algal Collecting Thwarted

"Following a weekend of heavy rain, the Bureau also reported that the water level in the Millgrove section of the Yarra River had exceeded the minor flood level of 2 metres and was still rising. According to the Bureau the Upper Yarra River catchment received 100mm of rainfall from 9am Thursday 24 September to Monday midday." So reported the Mountain Views Mail today.

My picture is from Dights Falls, a long way down stream, and not so flooded. This is as close as I got to the upper Yarra catchment today. So no algal collecting - I'll have to plan a return trip in summer I think.

Two reasons for the Dight's Falls picture. It's very near the Collingwood Football Club and I needed something to neutralise my weekend in Geelong (premiers of the AFL this year if you don't know - and anyone who visits Geelong would certainly know). It's also the site of one of the first collections of freshwater red algae from Australia.

In 1884, Henry Watts collected a specimen which later became the type (i.e. the specimen on which the name is based - as everyone who attended my talk in Geelong will know!) of a whole new genus of red algae (Nothocladus) now known from New Zealand, south-eastern Australia and...Madgascar (but I need to check that last record...).

He made his collection from around Collingwood, where he lived. Nowadays the species is only found up near Millgrove and Warburton - areas that feature in the newspaper story above. I've always presumed pollution and development along the Yarra has meant the distribution of the species has worked its way up stream.

Today I paid homage to Henry Watts and to Collingwood, among other things. Tomorrow I'll spend a day in the National Herbarium of Victoria, pehaps even examining a specimen or two by the late Mr Watts. (If all this algal talk tires you, don't worry, I'll be sure to feature some orchids next week when I holiday in the Grampians.)

From Birds to Cats - the road to Geelong

I broke the (short but not particularly scenic) journey from Melbourne to Geelong with a stop at Werribee Park. I'd always wanted to look at the garden and sculpture walk around this majestic 1877 house.

Lovely sweeping lawns and pretty flower beds, but also a great collection of lichens on the concrete balustrade. My pictures show the Parterre (the 'on the ground' display of annuals) from the balcony and looking towards the house. The bird-like creature created from plants? That was just in the garden somewhere but it was cute.

The following picture, like an artist's palette, is the top of the balustrade.

The sculpture walk includes lots of great pieces, including the one below which has a nice link to my pictures from yesterday of the forests recovering from fire.

Finally I reached Geelong, and guess what - apparently they won the AFL Grand Final. Who would have guessed...

Fire, Flood, Frost and an Historical Puzzle

I must be in Victoria. The drive from Alexandra through to Narbethong, then along the Acheron Way to Warburton took me through forests regenerating after the fires, flooding rains and then finally snow.

I'm on my way to Geelong for the 2009 conference of the Australian Native Plants Society (Australia), called ASGAP 2009 after their former name, Society of Growing Australian Plants. I'll be attending for the first day to talk about 'Those Changing Names'. The mood in Geelong will depend on what happens at the MCG today...

My plan was to collect some algae from the streams north of Melbourne on my way through. Sadly that has been thwarted by a couple of days of heavy rain - the rivers are too fast and high to see or collect the algae I'm after. I'll try and recollect on Tuesday, on my return to Melbourne to spend a day (looking at, instead of for, algae) in the National Herbarium of Victoria, at the Royal Botanic Gardens Melbourne.

Then a couple of planning meetings for the 2011 International Botanical Congress, before I head off for a week's holiday in the Grampians. If it stops raining, the Grampians should be fertile ground for some plenty of terrestrial orchids and I'll post a few pictures.

So why am I looking for algae around Melbourne? It's all part of finding out what red algae grows in Australia and where, and then working out they fit into the world evolutionary tree for this group - it turns out most are distinctly Antipodean, with a well supported group having evolved quite separately in Australian and New Zealand.

There are some particularly interesting species in the creeks north of Melbourne which I need to collect for DNA analysis. I also need to confirm that a rare species known only from 'Hermitage' comes from near Narbethong rather than Perth! The story goes a little like this (if you want the full background see the ASBS Newsletter no. 128, September 2006, online):

A few years back I was working with Helen Foard on some old collections of freshwater red algae from overseas herbaria, in this case Uppsala in Sweden, when we discovered a single collection of a new species. In 1997 we named the species 'goebelii' after the collector of the specimen, Professor Karl Immanuel Eberhard von Goebel. The label said simply "West Australien, Hermitage, 1898". At the time of publishing the species we were unable to find find a locality ‘Hermitage’ in Western Australia.

With some assistance from Germany we found that Goebel arrived in Western Australia on 3 October 1898 and travelled around the South-West until 28 October of that year. From there he sailed on to Adelaide, Melbourne and Hobart before crossing to New Zealand. Early in the next year he apparently returned to Sydney, Melbourne and Adelaide before heading on to Sri Lanka around March 1899. So it seemed reasonable to assume that the collection labelled ‘Western Australia’ and ‘1898’ was from somewhere in the south-west of Western Australia.

There was a second collection of red algae from the same location and it turned out to be an apparently isolated occurrence of a species otherwise knownly only from central Victoria, southern Tasmania and the south of the South Island of New Zealand .

A little later Roberta Cowan at Murdoch University located in a gazatteer a small settlement called Hermitage on the Moore River, near to New Norcia in Western Australia, but this wasn't on Goebel's itinerary (it was 100 km or so away) and it seemed an unlikely habitat for these particular species.

Then, Aliston Vaughan from the Royal Botanic Gardens in Melbourne made this startling discovery: Goebel had stayed at, and collected near, ‘The Hermitage’, near Narbethong. This is within the known range of the second species and likely habitat for the new one.

And so today, I drove, in the rain, to Hermitage. As I said, the streams were just too high to collect from so I'll have to come back another day. I did see some typical red algal habitat very near to the sign below, so I may be getting close to solving my historical puzzle...

The Green Planet

On the day Sydney looked like Mars (this is the view from my office this morning), the obvious question is: If plants had evolved on the red planet, would they be green?

Scientists analysing the first data sent back from the Phoenix Mars lander last year announced that an asparagus plant would grow in a pot of Martian soil. The dirt from the northern arctic plains of Mars, said Samuel Kounaves from Tufts University, had all the nutrients a plant would need and was a little alkaline, just the way asparagus likes it.

A month or so later, however, there were reports of a chemical called ‘perchlorate’ in the soil, which certainly wouldn’t encourage asparagus growth – it’s a bit like bleach. But that chemical may be scattered in distribution and not a big problem.

Elsewhere on Mars, the lander was picking up signs of water, albeit without confirmation that water still exists on the planet. It was already known that the atmosphere is primarily carbon dioxide. So everything exists, or existed, to grow an asparagus.

But if there was ever life on Mars and it evolved into plant-like things, what colour would they be? Because there is plenty of sunlight reaching Mars and our sun is one the bright ones, you could reasonably expect lovely green asparagus.

However, as I suggested on radio recently, picture yourself on some far-flung planet not so close to a star. You might look out the kitchen window at your freshly mown black lawn and neatly cropped purple box hedge. A little further in the gloom you may be able to make out a few maroon shrubs and a very shady looking tree or two. If your planet doesn’t have an energetic young sun like Earth, your world is likely to be always a little dull. But couldn’t the plants at least provide a little colour to brighten your day?

According to Nancy Kiang, a NASA scientist working in New York, plant-like things growing on another planet are unlikely to be green. Green is a compromise colour and one that wouldn’t work in a planet orbiting a sun in the twilight of its life.

Dr Kiang is trying to help space explorers target planets that might be suitable for plant-like life and suggest to them what these living things might look like. The key defining characteristic of ‘plant-like’ is photosynthesis – the process of using energy (here on earth, the sun’s energy) to turn carbon dioxide and water into sugars and oxygen.

Many planets won’t have the bright star we have to provide all that light energy. Red dwarfs, for example, produce only a small fraction of the visible light we get from our Sun. So plants on a planet orbiting a Red Dwarf would need to hoard all the light they can get, rather than reflecting some of it back the way plants on earth do.

In any case, a light hoarding plant on a planet near to a Red Dwarf would reflect hardly any light and might look black or purple. However Kiang says it is unlikely you will find a blue plant on any planet because blue light is particularly yummy for a plant.

Kiang thinks there are plenty of planets capable of hosting plants in range of odd colours. So when you are next gazing at planets with your telescope, look to see if they are covered in dark coloured vegetation. Just don’t expect to see a blue moon, or planet.

Back on earth, most photosynthetic plants don’t absorb green light, reflecting it back to us and give them their distinctive colour. There are purple bacteria, and brown and red seaweeds (see next section), but mostly our photosynthetic life is a shade of green.

This might seem a bit odd given that sunlight reaching the Earth’s surface is rich in green light. So why are most plants on earth green, and what is the lesson for us earth-dwellers?

Firstly, life is compromise. Red light is rich in photons, and blue light more energetic, so plants may have evolved to use the more ‘nutritious’ reds and blues. A purplish variant may have been able to use more of the sun’s energy but it may also have been easy to spot, and eat, by some vigilant insect or wildebeest. A purple plant may also have become too warm to function at its best – compare your own performance in a (non-air-conditioned) black versus white car on a sunny day.

Secondly, life is the result of successful adaptations, not some a priori grand plan or design. As the environment changes, some plants are better adapted to that change and survive to produce more offspring. Not all possibilities, and combinations of possibilities, are explored. The living world we inhabit represents one track of evolution, one of a many possible worlds.

Thirdly, contrary to Voltaire’s Dr Panglos, there is no reason to believe this is the best of all possible worlds? It’s just one of them. There may be a planet out there with purple plants and that planet may be more what Dr Panglos was imagining.

For now though, we are stuck with Earth. Interestingly, although we call it the green planet, it is mostly blue due the predominance of the oceans, and in any case only the big obvious plants are green.

Our Northernmost Coastal Banksia

The Coastal Banksia we know and love in New South Wales can be found to about half the way up the coast of Queensland, and south to Wilsons Promontory in Victoria. But is does vary along the way.

The ‘typical’ form – and the very first scientific specimen – was collected by Sir Joseph Banks from Botany Bay in 1770. I have a specimen from this gathering in a cabinet once used by Banks, now in my Director’s Office at the Royal Botanic Gardens.

Overlapping with the range of this typical form is a subspecies called monticola, found from the basalt outcrops of Mount Tomah and Mount Wilson up to south-eastern Queensland, and one called compar further north, up to about Mackay.

A fourth variant, once considered to be a subspecies of Banksia integrifolia, but since 1996 considered to be a distinct species, is now called Banksia aquilonia. It’s only found naturally in northern Queensland, in coastal and mountain areas from Paluma Range to Mount Finnigan National Park, but also on Hinchinbrook Island. It’s called Jingana by the Jirrbalangan people of Tully, and sometimes the Northern Coastal Banksia by others.

We have 27 year-old Jingana in flower, beautifully photographed by Simon Goodwin above, on the corner of the National Herbarium of New South Wales. It was collected from the Atherton Tableland in 1982.

Banksia aquilonia is different from Banksia integrifolia in having a row of short, stiff brown hairs on either side of the middle ridge on the underside of the leaf. The valves that open to release the seeds are also slightly larger than those of Banksia integrifolia.

It’s a species that could be grown more widely than it is – obviously it’s pretty hardy given how well it toughs it out beside the herbarium. At least it’s at the northern end of the building.

King of the Ferns*

The eight metre long fronds of Angiopteris evecta are the largest produced by any fern in the world. The King Fern (also known as Giant Fern or Mule’s Foot Fern) can also have a trunk up to three metres high and one metre across.

It’s not to be confused with Todea barbara, a local fern that is also called the King Fern. It’s very impressive too, but doesn’t have the massive fronds of the Angiopteris.

There is one preserved specimen of an Angiopteris frond in the National Herbarium of New South Wales (here in the Royal Botanic Gardens) that was collected from Tweed Valley in 1909. It’s thought the species was once scattered around the far north-east of the State, possibly extending as far south as Byron Bay.

The species was presumed extinct in New South Wales until a single living plant was discovered in December 1977, growing naturally in the Tweed Valley. Occasional reports of other occurrences have not been confirmed.

Its distribution in Australia is sporadic. It’s known from Carnarvon Gorge, Fraser Island and then more common in the wet tropics of far north Queensland, and there is only one small population in the Northern Territory, in north-eastern Arnhem Land.

Outside Australia it occurs from Madagascar to tropical Asia, and it’s relatively easy to grow in a protected, moist location in a Sydney garden. It has been planted widely throughout Asia and the tropics and has become invasive in Jamaica, Hawaii and Costa Rica.

Fossilised fronds very similar to those of the King Fern have been found in rocks about 300 million years old. Ferns and their relatives, such as giant clubmosses, were the dominant vegetation before flowering plants evolved and ferns like the King Fern were among the earliest large plants to colonise the land.

This is before the great southern land of Godwana split away from other parts of Pangea, so what was to become Australia was still connected to Europe and North America.

We have a couple of King Ferns in the Royal Botanic Gardens, including a large specimen in the Fernery and one beside the Botanic Gardens Creek, near our Restaurant. Both grow near to specimens of the ‘other’ King Fern, Todea barbara.

I believe the Creek specimen is celebrating its 40th birthday this year. At least that’s how long it’s been with us – it may well have been planted as an already large, giant fern.

Image: The King or Giant Fern in the Fern House at the Royal Botanic Gardens

*This Passion for Plants posting will also appear on the ABC Sydney website (possibly under 'gardening'), and is the gist of my radio interview with Simon Marnie on Saturday Morning sometime between 9-10 am on 702AM.

l'Apricot

“...the only item of benefit that the Crusades had brought to Europe was the apricot.”

So says Andrey Hussey in Paris: The Secret History (2006), which I strongly recommend you read if you like Paris and a little history. Admittedly this quote is about as close as it comes to botany and Hussey is repeating here the opinion of "veteran French medievalist Jacques Le Goff".

If only to provide a little more rationale for running this quote on my blog, contrary to its botanical name, the apricot, Prunus armeniaca, was probably bred from wild stock in northeastern China rather than Armenia, some 4,000 years ago (although Wikipedia suggests India, about 3,000 years ago).

From China (or India) it eventually made its way to Europe, via Persia, to Italy around the time of the first botanic gardens, then to King Henry VIII's garden in the UK and later to California via Mexico. Presumably our apricots came across from London.

Anyway, it's here now and tastes great.

Image from http://science.howstuffworks.com/fruits/apricot-info.htm

Shake your Bouddi

Seeing as I'm spending the weekend near Bouddi National Park, here a few pictures from Box Head (behind Pretty Beach and Hardys Bay), in the late flush of sprinter.

In Reflections from the Beach and the Bays, compiled by Jillian Baxter, John & Gwynn Wakeham recall the decline of Rock Orchids in the area "which...used to stretch from their cottage down into the sandstone ridges covering the ground with their cream flowers in season".

I'm sure there are still some Dendrobium speciosum around, but their blooms no longer cover the ground. The only orchid I saw was a Donkey Orchid, Diuris aurea (I think - I'm a little rusty on my orchids and will have to check the species name in my books at home).

Other plants featured below are Isopogon anemonifolius (group of yellow flowers), Eriostemon australasius (pink flowers), a very pretty, but small pea that I haven't identified yet (purple flowers) and of course a Flannel Flower (white flowers). All fairly common, but who can resist photographing and posting them. Not me.

Power Plant

"As far as we know this is the first peer-reviewed paper of someone powering something entirely by sticking electrodes into a tree."

So says one of the authors of a paper about to be published in Institute of Electrical and Electronics Engineers' Transactions on Nanotechnology, as reported in the University of Washington News.

Apparently up to 200 millivolts can be generated by sticking one electrode in a tree and the other in nearby soil. The pioneering researchers (Babak Parviz, Carlton Himes, Brian Otis, Eric Carlson and Ryan Ricchiuti) from Massachusetts Institute of Technology powered an electrical circuit entirely from this power source.

Their undergrad student spent summer hooking nails to trees on the university campus, discovering that larger leaved maples were the real power plants.

Others in the team built a ‘boost converter’, which turns the measly 20 millivolts into 1.1 volts – don’t ask me how, I’m a botanist!

Apparently one of the problems with this technology is that the boost converter and related electronics would “spend most of their time in sleep mode in order to conserve energy”, succinctly described as “creating a complication”.

To avoid the system going to sleep and never waking up, a clock was built that runs on 1 nanowatt, producing an electrical pulse every few seconds to wake up the system. I love this kind of physics talk - perhaps my physicist brother Colin can tell me this actually means!

The researchers are keen to point out that this tree-power is quite different to potato or lemon systems where two different metals react to create a potential difference across the tuber/fruit creating a current. To avoid confusion with the ‘potato effect’ (as they call it), the researchers used the same metal for both electrodes.

They are also quick to point out that tree-power is not going to be a substitute for solar-power. Rather, it could provide a cheap way to run tree sensors measuring e.g. environmental changes in forests. Or perhaps the electronic output could be used as a measure of tree health – a kind of pulse for a plant.

The researchers don’t know where these voltages come from or why, but they wonder if they have some kind of signalling role.

All very stimulating…and quite odd.

Image: An installation from Future Gardens, held in the Royal Botanic Gardens Sydney in October 2004

All is Leaf

I’ve been waiting to use this quote, attributed to the German poet, thinker and kind-of scientist, Johann Wolfgang von Goethe. And this picture is one I took last year at the first botanic garden in the world, in Padua near Venice – it’s of a glasshouse built around a palm admired by the very same Goethe.

The story, though, is about the origins of flowering plants, a topic I’ve touched on before.

In a very nice article in Monday’s online New York Times, Carl Zimmer first reminds us of Charles Darwin’s interest in this topic – “the abominable mystery” as he called it.

In Darwin’s day there were no fossils from rocks older than 100 million years ago, the time when the flowering plant architecture arose.

Not only do we have flowering plant fossils from older rocks (to 136 million years), we read the story of a plants history in its DNA. The latest discovery is that, as Zimmer puts it, “flowers evolved into their marvellous diversity in much the same way as eyes and limbs have: through the recycling of old genes for new jobs”.

The early fossils are still open to interpretation and the signal is too noisy, so far. Comparison of DNA sequences has identified long unforked branches (sometimes called basal branches because they are represented in most “trees of life” as arising from the base of the trunk) that tell us something about the early flowering plants – see my earlier posting on Amborella.

Although Amoborella from New Caledonia excites evolutionary botanists, it’s the fruit fly of the plant world, Arabidopsis (see my posting on this genus) that has given us clues to where the flower itself came from. We’ve known since the time of Goethe in the 18th century, and probably before, that flower parts probably started as a weird kind of leaf. You get a hint of this occasionally when a deformed petal or other floral bit becomes leaf-like. “Alles ist Blatt (All is leaf)” said Goethe.

Zimmer describes some of the genes responsible for flower parts, reporting on research showing how petals in some flowering plants have evolved from different but related genes.

Then there is the famous ‘double fertilisation’ of flowering plants – the egg, as well as the sack of food reserves around the egg. Zimmer gives the latest theories on how this arose and discusses the debate among scientists as to whether this is much of an advantage to flowering plants and the secret to their dominance of forests on earth today.

Read Zimmer's article...

Three Books that Plant Ideas

Each of these books deserves its own posting but time is not on my side at the moment. They are quite different but each of them does what we try to do as a botanic garden: inspire the appreciation and conservation of plants.

Trees of History and Romance – Essays from a Mount Wilson Garden, by Michael Pembroke. Illustrated by Libby Raines.
I was lucky enough to read a draft copy and have commented already on the dust jacket about how much I enjoyed this book. Written and illustrated by two Mount Wilson (at least one partly transient) residents, this is a book to dip into, to savour, and to learn a little from. It’s written by someone who obviously loves plants and the stories that go with them. It’s a wonderful read.

Australia’s Remarkable Trees, by Richard Allen and Kimbal Baker.
I have a friend who describes these kinds of books as botanical pornography. He means this in a nice way – the pictures and words are so seductive. And this is a great example. Beautiful pictures and fascinating stories (I bought it for the articles…). It will make you want to visit the trees and to look after them.

Germplasm Conservation in Australia – Strategies and Guidelines for Developing, Managing and Utilising Ex Situ Collections, edited by Catherine A. Offord and Patricia F. Meagher.
The longest, and quite explanatory, title. Not a book to cuddle up with in the evening, or to drool over, but perhaps of the three the one that may most directly save the world. It’s all about how we store seeds and other bits and pieces of plant so that we have a back-up collection should something awful happen to their natural habitat. The seeds can be planted out again to restore vegetation or be used to maintain the species if we want to keep that genetic line alive. It’s very practical, very accurate and very important.

Say no to moss, yes to coconut

At the Botanic Gardens we stopped adding moss peat to our potting mixtures more than 15 years ago. Instead, we generally use ‘coco peat’ (or ‘coir’), made from the husk of a coconut and readily available as a by-product of the coconut industry, as well as composted pine bark.

A study just out from Italy gives the thumbs up to coco peat, although they still mixed in a little of the moss peat.

Classical peat is good addition to a potting mix - retaining water and adding extra nutrients – but its extraction from the wild is generally unsustainable. Note that I understand harvesting of living peat moss can be sustainable under certain circumstances. The dry moss peat is formed when the moss sphagnum and other bits and pieces partly decay in swampy land called peat bogs.

To extract the peat these wetlands are drained and destroyed. In addition to the environmental impacts, peat is now becoming difficult to source and expensive.

So the researchers from the University of Turin tested five different peat substitutes, mixed with some standard peat, and found that coconut fibre was the best.

They used camellias as their test plant because they grow well in acidic soils and are often grown in pots. (If you are interested, the cultivars were ‘Charles Cobb’s’, ‘Nuccio’s Pearl’ and ‘Dr Burnside’.)

They tested green compost (grass clippings and leaves), pumice, fibre from coconut husks – composted and uncomposted, and pine bark.

Each of the alternatives was as good as, or better, than straight moss peat, except for the green compost which raised the pH of the mix. Coco Peat was recommended, with some adjustment to fertilizing and watering compared to straight peat.

If you use coco peat straight, you would definitely need to add a little something for you plants to live on.

Image: Coco peat, from a supplier site

Gommier Chou?

George Lambert’s sculpture of Henry Lawson is dwarfed these days by a magnificent Cabbage Gum. The bronze Lawson, with swagman and dog, was installed in 1931. The tree is probably younger, but now envelops the sculpture. Right now, it’s in flower (see end of posting).

Cabbage Gum is a name applied to various gum trees with largish leaves, and the botanical name, Eucalyptus amplifolia, means the large-leaved eucalypt. That said, I’ve seen gum trees with bigger leaves….

Eucalyptus amplifolia is one quite a few (how many I wonder?) species of eucalypt described from specimens cultivated overseas. One of the most famous is Eucalyptus camaldulensis, the River Red Gum, which was described from a private garden in Camalduli, near Naples in Italy.

In the late nineteenth century, the Cabbage Gum was growing in the Bois de Boulogne of El Jazair, in Algeria, and in two gardens in France – the Jardin du Riou, in Cannes, and a private garden in Florence. It was described from these specimens in 1891 by the French botanist, Charles Naudin, who I think was the first Director of the Jardin Botanique de la Villa Thuret in Antibes.

Back in Australia, the Cabbage Gum grows from southern Queensland through to the Bega area in New South Wales. It can be locally common but it features in a now endangered ecological community called Sun Valley Cabbage Gum forest. This assemblage survives only in Sun Valley, in the Blue Mountains.

Apart from eastern Australia and Europe, the Cabbage Gum is also grown widely in at least China.



Images by Simon Goodwin, The Domain, 9 September 2009

Indoor Plants Good, Bad and Ugly

As I’ve said before, indoor plants are a good thing. They are pretty, they make you feel happy, they overwhelmingly turn carbon dioxide into oxygen and they can extract nasty things from the air.

They also have their bad side, apparently. As well as removing what are called ‘Volatile Organic Compounds’ from the atmosphere, they also release some back again.

Research from the University of Georgia looked into the ‘VOC’ emissions of four potted plants - Peace Lily (Spathiphyllum wallisii), Snake Plant (Sansevieria trifasciata), Weeping Fig (Ficus benjamina), and Areca Palm (Chrysalidocarpus lutescens).

A grand total of 23 VOCs were released. Interestingly, some of the VOCs are part of pesticides that were applied to these plants during their early growth. Some VOCs came from micro-organisms living in the soil rather than the plants themselves (but remember the same micro-organisms are responsible for absorbing nasty VOCs as well). And 11 VOCs came from the plastic pots!

There were more VOCs released during the day than at night, with release seeming to be linked to the synthesis of at least some of these chemicals. How long the VOCs remain biologically active and whether they are deleterious to humans is not know.

But don’t let that put you off your indoor plants. They still absorb plenty of VOCs and as a recent study from Texas State University notes, us city folk spend more than 80% of our time indoors and plants help in ‘reducing tension, better coping mechanisms and increased concentration and attention’. They have also been shown to ‘reduce eye irritation and stress, motivate employees…a positive effect on headaches and fatigue and hoarseness, ...[reputedly] less dry skin…increase work productivity’. On the latter point, one study showed the presence of plants improved reaction time for computer tasks by 12%.

So obviously the next step is to plant out our classrooms (being careful to keep VOCs low…). This is exactly what the Texas University researchers wanted to test. For a whole semester they had some students studying amid tropical plants, and others in plant-less rooms. They also tested rooms with windows and those without. The student’s grades were compared at the end – along with lots of demographic data to check for other biases.

Sadly for the vision of Australian students peering out from tropical jungles, there were no differences in the grades or performance attributable to plants.. However the students amid the plants felt that the learning and enthusiasm of the teachers was higher. The lucky students who spent a semester in a windowless, stark room were not particularly satisfied when compared with the others. So it may be that plants can be a substitute for windows in making students feel a little cheerier and more positive, but they are no substitute for DNA and dedication to study it seems.

Image: this is my ‘ugly’ plant. It was the Christmas Tree (a seeding silver beet) in a student house I lived in many years ago...

Mangoian History (P4P*)

It’s nearly magnificent mango season. We have two mango trees in the Royal Botanic Gardens, both in the middle part of the gardens towards Farm Cove. I can’t recall ever seeing fruit on them, for which we can thank our local possums.

Mangoes have been in cultivation for so long (about 4000 years) we can’t say for certain where they first came from. It’s most likely they are native to somewhere like Burma or southern India.

Mangoes were grown commercially in North America by the 1860s and came to Australian horticulture soon after. In the later part of the nineteenth century mangoes were imported from India to Australia at Bowen, just north of the Whitsundays in Queensland. Seeds from these fruits were planted locally and by the late 1880s there was an orchard called ‘Kensington’ providing fruit for the local market.

Mangoes were growing closer to hand. Charles Moore was apparently growing fruiting trees in the Gardens as far back as 1852. And when Captain Flinders was circumnavigating Australia in 1803, he stopped off at Timor to eat mangoes among other fruits to help fight off scurvy in his crew.

Mangoes are now grown commercially in tropical and subtropical Australia, in Western Australia, Northern Territory, Queensland and northern New South Wales. You can get mangoes to fruit in a protected spot to fruit in Sydney, but you have to get them before the possums and fruit flies do.

There are over a thousand different varieties of mango in the world, with about nine commonly grown in Australia. The varieties differ in the fruiting season, skin colour, texture and taste. One of the popular early varieties is Kensington Pride, also known as Bowen, both referring to where mangoes were first grown in Australia.

About 80% of mango trees grown in Australia are this variety, but it is not grown commercially overseas. Apparently Australians have a distinctive taste preference in mangoes. Of course they not only taste good. One mango has 1-3 times the daily recommended intake of Vitamin C and lots of antioxidants, including beta-carotene. No wonder mangoes are the second largest tropical fruit crop in the world, after bananas.

The mango (Mangifera indica) is in the same plant family as pistachio and cashew, as well as poison ivy and the tree widely planted near homesteads in inland Australia, the (South American) Pepper Tree.

If you are planning to save and germinate your mango seed, the Kensington Pride or Bowen will grow true to form, but for most mangoes grafted plants produce fruit sooner. And that should keep you and the possums happy.

Image: Part of a giant Mango tree in Sandakan, Borneo.

*This Passion for Plants posting will also appear on the ABC Sydney website (possibly under 'gardening'), and is the gist of my radio interview with Simon Marnie on Saturday Morning sometime between 9-10 am on 702AM.

Smells Like Bee Spirit

Is there anything orchids won't do to get pollinated? The latest discovery is a flower that smells like a stressed bee to attract bee-eating hornets.

According to a paper published in the latest issue of Current Biology (volume 19, pages 1368-1372), about one-third of the world's 30,000 orchid species deceive their pollinating insects. The flowers trick the pollinators into visiting by imitating flowers that do deliver, or by smelling like a potential mate.

The plant doesn't waste energy producing nectar, and the insect leaves empty footed but carrying some precious pollen to the next flower. Remember that cross-fertilisation is the engine of evolution.

Now there is a new twist on this theme. Dendrobium sinense, from China (as its species name suggests), is pollinated by a hornet that sniffs out something called '(Z)-11-eiconsen-1-ol', better know as the smell of a stressed bee. This pheromone is produced by Asian and European honey bees and has never before been found in a flower.

The orchid flowers are white with a red centre (see above) and offer no reward to the hornet other than the perfume of an unhappy bee.

The researchers from Germany and China - Jennifer Brodmann, Robert Twele, Wittko Francke, Luo Yi-bo, Song Xi-qiang and Manfred Ayasse - set up dummy bees impregnated with the floral scent to show that the smell was in fact attractive to the hornets.

There may be other species with the same pollination trick. Another wasp-pollinated orchid, Steveniella satyrioides, is the next to be studied. The scientists wonder whether mimicking the scent of prey may be common in those wasp-pollinated orchids that offer no food reward.

Other than revealing another fascinating orchid pollination story, this discovery may be useful in developing a safe system for trapping hornets that frustrate beekeepers.

Image: Dendrobium sinense and its pollinating hornet, Vespa bicolor, with a pollen mass on its back. This picture is from Daily Mail on-line and the scientific paper can be purchased from Current Biology.

The Rastafarian Palm from New Caledonia

Quite a few of our palms are in flower or fruit at the moment. If you take the walk behind the Tropical Centre you'll see just a few of our extensive palm collection - in total some 2000 individuals representing 140 different kinds of palm.

If you arrive from the Morshead Fountain Gate opposite the State Library, one of the more curious flowering structures can be found in a group of three palms just at the fork in the path that leads one way towards the Pyramid and the other around the Expressway side of the route around the Arc.

These palms are called Burretiokentia hapala. Their flowers are borne on velvety tentacles or fingers that protrude out from the stem of the palm. The look and texture of this inflorescence is hard to describe but in the pictures above, taken by Simon Goodwin, you see they are a little spider- or octopus-like, perhaps like the hairdo of The Simpson's Sideshow Bob, or more closely, Rastafarian dreadlocks.

The palm is know only from forests in northern New Caledonia, where it is listed as a species 'vulnerable' to extinction, although it flourishes locally after selective logging. Fire and the trampling of seedlings by hunters and climbers are the biggest threat to its survival.

There are 37 species of palm in New Caledonia, but that number is expected to at least double once the results of current taxonomic research are published (Burretiokentia hapala was only discovered in 1964). As with the palms on Lord Howe Island, every one of these species grows here and no where else.

Palms are just part of the botanical appeal of New Caledonia. It's chock full of fascinating plants, many with evolutionary links to the Australian flora. The country is about three-quarters the area of the Sydney region, but supports at least 3,500 species of vascular plants (flowering plants, conifers, ferns etc.). Around Sydney we have about 2,000 species of vascular plants and we quite rightly recognize it as one of the great wildflower regions in Australia!

Like Australia, New Caledonia has 80% of its species that occur no where else in the world.
New Caledonia separated from Australia 65 million years ago (part of the Gondwanic split), and many of the plant groups are related to those of Australia, but with different species.

Again like on Lord Howe Island, this palm species doesn't have any close Australian relatives. However unlike the Kentia Palm from Lord Howe, New Caledonian palms are generally not easy to grow, and the collections in the Royal Botanic Gardens in Sydney are important for conservation and science.

Five seasons, and over and out

As media interest in changing our seasons starts to wane at last, perhaps as we move closer to ye olde 'spring' - or at least the day where Australian's tend to start spring - I present this lovely diagramatic illustration of a possible Five Seasons system for coastal Sydney, thanks to Karen Rinkel, one of our talented Graphic Designers at the Botanic Gardens.

Over the last two weeks, there have been more than 30 media articles and broadcasts – 4 newspaper, over 25 radio, 4 TV and 3 web. Interest spread out around all states in Australia and then internationally (BBC Worldservice, UK and Scotland, and two NZ radio stations).

Responses have varied but mostly people have enjoyed the chance to question our four-season system, and to think about the big biological and climatic changes in each year. It's clear that Indigenous communities have over tens of thousands of years come up with systems far more meaningful than our imported European schema. We could adopt these rather than my slightly plant biased system, or at least use local Indigenous names instead of my clumsy 'springer' and 'sprummer'!

Either way it would mean different seasons for different parts of the country but if that's the way it is, that's the way it is. Our calendar and clock (daylight saving differences excepted) are for keeping us all organised - seasons could be for tracking the changes in the environment around us. And do we change seasons as the climate changes? Perhaps. Maybe that's a good thing too.

Lots of questions and little resolution, yet. But it's a start...

Open Gardens, and Science

Firstly the launch of the 2009-2010 Australia's Open Garden Scheme at 'Yarrawa', in Burrawang, about an hour and a half south of Sydney. Dr Holly Kerr Forsyth spoke eruditely about the history of gardening, the beauty of Bruce Rosenberg's Yarrawa (a garden that features in Kerr Forsyth's most recent publication, Gardens of Eden: Among the World's Most Beautiful Gardens) and, simply, the 'need for gardeners to garden'.

The event was hosted, as always, and wonderfully, by the erasible Andrew Buchanan. The garden of Yarrawa was very pretty and beautifully designed. My pictures below show just some of the many helibores - after four days of trimming to remove dead leaves apparently - and the patch of restored Yarrawa Brush at the entrance to the property. The garden is only 15 years old. It began as a bare paddock with a few (magnificent and large) Brown Barrels (Eucalyptus fastigata).

For information on the Open Garden Scheme, and a copy of the 2009-2010 Guide click here. For a few pictures of Yarrawa, see here...

From Burrawang, to Woccanmagully (or Wogganmagule). Here, in what is also called the Royal Botanic Gardens, in Sydney, our science was 'open' for the day. Talks, tours, games, displays and Rotary BBQ'd sausages, as well as scientists at work - sorting seeds, examining plants under the microscope, preparing herbarium specimens and illustrating.

Here are a few pictures of the day... You can see Steve Paul and Kathy Pfleger (Community Greening), Lesley Elkan (Illustrating), Amelia Martyn (seed sorting) and Karen Wilson (looking at a spring wattle under the microscope).

TV Spring at Night

I've just had the disconcerting experience of being interviewed for TV in the middle of the Royal Botanic Gardens lit up like a spotlighted rabbit, with an earphone in my slightly deaf ear (the right one) and the 7-second delay on my voice feeding back into the same earphone.

I could hear the questions, just, and miscellaneous night noices and what I took to be some audience participation (i.e. I think they laughed occasionally). So I said my piece, about the need for an early spring and an extra season, and with relief my goodbyes when we seemed to have reached the end of the questions.

Odd and not very pleasant. Depressed, I made my way home determined to never do a TV interview at night, put the earphone in my left ear the next time, and try and work out a way to stare down the camera at the same time as remembering all those witty things I was going to say.

My family very kindly taped it for me, so with some trepidation I thought I should watch it so I could improve for next time. Ah, the magic of television. Somehow, and I don't know how, it actually looked and sounded like I knew what was going on and was in some kind of control. Amazing.

If you are not a regular watcher of the '7 PM Project' on Channel 10, you have the opportunity to review my performance on the web (it might not be up yet, but perhaps in the morning). Just remember that I'm still recovering from the experience...

For a slightly more coherent line of argument, see the ABC Online report. For some sometimes very passionate responses to my ideas, read the comments below. It's funny how this topic divides people into two main groups: the first want to know why I don't have something better to do with my time, the second have been thinking much the same thing but usually with slight adjustments.

I think it's a fascinating topic and quite pertinent to how we observe and respond the world around us. But then you know that.

Sea Change (P4P*)

The kind of plant we might display in the botanic gardens later this century? (It's a picture I've used before but too good to resist for this story.)

The land seaward of the Gardens Restaurant in the Royal Botanic Gardens was reclaimed from the sea over a period of 30 years in the mid nineteenth century. In the next 30 years some of it could well be claimed back.

Modelling by the Department of Environment and Climate Change, our parent Department, predicts a 40 cm rise (above 1990 levels) by 2050, and a further 50 cm by 2100. So we’d expect the harbour to be nearly a foot higher in 30 years time.

Our Seawall should cope with this kind of sea level rise, although king tides are likely to reach further into the Royal Botanic Gardens. Already they dump seaweeds on the paths, and occasionally fish and other marine life, but these all arrive through the deliberately cut slots in the wall.

Even centimetre rises will increase the likelihood of flooding, and of the soil becoming even more saline. The bottom lake in the Royal Botanic Gardens has always been brackish and water flows back and forth from Farm Cove, depending on the sea level.

Mullet and long-finned eels also travel through this channel between Farm Cove and the pond, although the eels can do it overland on a rainy night (in fact the mature eels have to leave the pond to spawn, migrating all the way to New Caledonia).

Accelerated climate change in the Sydney region is also likely to increase minimum and maximum temperatures by up to a couple of degrees. Summer rainfall on the coast is likely to increase (but not necessarily in the catchments), but winter rainfall is more likely to decrease.

These changes to the climate will eventually affect what we can grow in the Royal Botanic Gardens. Some plants can tolerate wide variations in temperature and water availability, while those grown at the extreme of their range may succumb. Because we display many different plants, from all around the world, some will much harder to keep alive.

If we have more, or more severe, storms and winds, that will obviously affect how we care for existing trees and the kind of trees we plant over coming years.

So what can we do? Already, when we replaced the stone wall around our two islands in the Main Pond recently, we took the opportunity to make then 50 cm higher. In our reviewing our ‘thematic plans’ (our guides to what grows where and why), we’ll take into account likely changes in salinity along Farm Cove and perhaps require that all new trees planted in the lower garden are in raised beds or mounds. In any repairs and maintenance to the sea wall we’ll take into account likely sea level increases and the increased threat of storm and tidal damage.

In Sydney generally, our gardens will change. You should look at the effects of the 40+ degree day in coastal Sydney on New Year’s Day in 2006. Tree ferns growing out in the open may be a thing of the past, as might be box hedges in planter boxes. Consider bromeliads, succulents or local native plants, but also water-loving gardens in seepage areas and near your rainwater tank.

On the positive side, our gardens have already adapted a little due to the new watering regime (recently relaxed so we can water every day, early in the morning and later in the afternoon). Although most gardeners would prefer some more flexibility in the system, most of us probably over watered our gardens in the past. We’ve all lost a few plants but we are planting and preparing more wisely now. Even though we may get more summer rain, other seasons could be quite dry and the higher temperatures will lead to more evaporation.

Meanwhile, do all you can to reduce your carbon footprint and you may save, among other things, the Royal Botanic Gardens.

*This Passion for Plants posting will also appear on the ABC Sydney website (possibly under 'gardening'), and is the gist of my radio interview with Simon Marnie on Saturday Morning sometime between 9-10 am on 702AM.

Flowering, For the Very First Time

It has been pointed out to me that eucalypts haven’t yet featured in my blog. It’s appropriate for me to feature this genus today, because a visitor to my office this afternoon described the genus as our one of our worst weeds.

So today I feature a species that has a long way to go before it becomes a weed. In fact there are only three individual plants remaining in its natural habitat in the Blue Mountains. Three! Remember Wollemi Pines number just under 100 mature trees in their remote canyon north of Sydney.

The suggestively named Eucalyptus copulans was discovered at Wentworth Falls over a hundred years ago but only named as a distinct species in 1991, by former Director of the Trust Lawrie Johnson and former Trust scientist Ken Hill. At that time it was thought to be extinct and the species name refers not to its virulence, but to this species ‘joining’ or being intermediate between two others.

Since the three surviving trees were discovered, 1000 or so seeds have been collected and deposited in the NSW Seedbank at Mount Annan Botanic Garden. We’ve grown on some of this seed and planted specimens in our botanic gardens.

In November 2003, Professor Peter Crane, Director of Royal Botanic Gardens Kew, and the Hon Bob Debus MP, NSW Minister for the Environment, planted a Eucalyptus copulans in the Rare and Threatened Plant garden just outside the entrance to the Maiden Theatre. They also planted a specimen of the rare Nightcap Oak (Eidothea hardeniana) from north-eastern NSW.

Both plantings were part of the official launch of ‘Seedquest NSW’, a partnership between the NSW Seedbank and the Millenium Seedbank UK to conserve 10% of the world’s flowering plants in our seed banks by 2010 (we are almost there, and the target will be met).

Today, nearly six years on, our 5 m tall specimen is bearing its first flower buds. They are only a few mm long but they signify big things – the successful conservation of this species, albeit outside its natural habitat.

Image: photographs of the budding tree taken on the weekend by Simon Goodwin.

Colour and movement

Contrary to some overseas perceptions, the Australian 'spring' is a colourful season. This mish-mash - and yes it really is a bit mished and mashed - gives a sense of the colour out in the Ku-ring-gai bush this morning, in mid-August. The pink flowers of the boronias were particularly intense.

Speaking of colour and seasons, but admittedly not of Australia and spring, why are autumn leaves more often red in America and yellow in Europe?

Fully functioning leaves are mostly green because they have more green chlorophyll (needed to process the sun's energy) than any other coloured pigment. In deciduous trees, the leaves change colour in autumn as the chlorophyll is recycled - either yellow as a default, or red if a new pigment, anthocyanin is produced. As I explained previously, anthocyanins may provide sun or pest protection, or both, or neither...

Researchers from the Universities of Haifa (Israel) and Kuopio (Finland) suggest we should look at evolution to see why there are more red autumn leaves in America than Europe. There study was published in the latest issue of the scientific journal New Phytologist.

They evoke a long evolutionary war between trees and the insects that use them as hosts. In autumn, insects such as aphids feed of leaves and lay their eggs. Aphids are attracted to yellow leaves so red leaves are a deterrent to this pest. But why do some leaves remain yellow?

Professors Lev-Yadun and Holopainen theorise that until 35 million years ago, much of earth was covered in evergreen tropical forest. A few ice ages and droughts led to the evolution of deciduousness as a way of coping through difficult times. It's proposed that the evolution of red autumn leaves, to ward of pests, also began during this time.

In North America, the trees and their insect pests migrated together along the long north-south mountain ranges as the climate changed. The evolutionary 'war' continued unabated.

In Europe the mountain ranges extend east-west and tree species that could not survive severe cold were more likely to die out, with their insect companions. At the end of the ice age cycle, many of the insect species were extinct and the surviving tree species has less need to spend energy on producing red leaves.

So the scientists hypothesise. Evidence for the theory includes dwarf shrubs that grow in Scandinavia which still produce red leaves. Smaller trees are more likely to survive ice ages becauase they can be protected from more extreme conditions under a layer of snow. The associated insects were also relatively snug and survived to fight another day.

As I said, all this has nothing to do with Australia or spring. My weak connection is that with accelerated climate change, it is important to have corridors for plants to relocate and to evolve. The beautiful bush at Ku-ring-gai is relatively extensive and has at least some connections to the north, although there isn't much mountain height (moving up and down is another way to cope with temperature changes).

And all this begs the question of why the sundew in the photo above is red. Obviously it doesn't repel the kind of insects it likes to digest. I suspect it's more to do with sun protection given the highly exposed places they live. Ah, evolution!

More Pictures of That Orchid....

Here are some more pictures of the orchid in the Port Jackson Fig, taken today. For more about the Bridal Veil Orchid see below. These pictures start with the tree, moving in towards the orchid plant and then its flowers.

I've also added at the end a picture of the climbing cactus, Queen of the Night (Hylocereus triangularis), identified by Simon Goodwin in the comment after my previous posting. As I noted there, and as befitting its common name, this is a plant you are unlikely to see in flower in the Royal Botanic Gardens - its flowers open at night and close by morning. Perhaps we need special summer viewing of this one, after hours.

And this is the cactus!

Mount Annan Botanic Garden Doing a Great Imitation of Spring, or Wattle Day...

Images taken Thursday 13 August 2009

Best Orchid in the Botanic Gardens?

We have this fantastic Port Jackson Fig near our Palm House. It's a beautiful tree in its own right, but around and in it are a bunch of equally pretty plants. In flower right now is the Thin Pencil Orchid, also called the Rat's Tail Orchid and Bridal Veil Orchid.

If you look up into the tree you'll understand why it's called the bridal veil - the flowers are like a cloud of white stars. And if you are lucky a waft of the perfume may drift your way.

Botanically it's a species of Dendrobium or Dockrillia, depending on the taxonomy you chose to use. At the moment we have it filed away as Dendrobium teretifolia. It grows naturally from the tip of Cape York to south-eastern New South Wales - David Jones in A Complete Guide to Native Orchids of Australia illustrates the species with a picture taken in Penrith.

According to Jones, in New South Wales it grows almost exclusively on Swamp Oak (Casuarina glauca), a species that still grows naturally in the Royal Botanic Gardens. We think our surviving plants of Swamp Oak are suckers from a tree that once grew on the edge of Farm Cove, before the cove was reclaimed in the middle of the nineteenth century. Perhaps the orchid also once grew here naturally?

The same Port Jackson Fig is host to a climbing cactus, some kind of Epiphyllum species I presume, but I'll check with Simon Goodwin or Gareth Hambridge and add a comment later to confirm. Underneath there are a few hundred bromeliads, newly planted, and freshly blogged. I'm pretty sure the fig itself is planted, but Ficus rubiginosa a common local species, and does occur more or less naturally on the site.

Image: a picture of our Bridal Veil Orchid taken yesterday by horticulturalist Gareth Hambridge, who says this years blooming is particularly stunning. He also describes this specimen as the best orchid in our collection.

Newcastle Heralds Five Seasons

Firstly sorry to interstate ABC radio audiences who have had to endure my Sydney perspective on life, seasons and everything. This whole seasonal thing has become a popular topic.

I thought I'd share with you an article from the Newcastle Herald by Jeff Corbett. Jeff has similar ideas himself and has published on this a few times already. Today he summed up the sitation nicely in an article headed 'Spring to the Cause' (Newcastle Herald, 11 August 2009, p. 8). Jeff was happy for me to post his story, and would welcome further debate on his blog. And for more of my own thoughts on seasons click here.

Spring to the cause (by Jeff Corbett, Newcastle Herald, 11 August 2009)

"IT'S an indefinable something that produces an indefinable sensation, and it happened on Sunday. That was the arrival of spring.

Yes, I know spring does not happen until September 1, and that this date has been kicking off the Australian season of rebirth ever since the early 1800s when bureaucrats brought it forward from the spring equinox. They advanced spring by about three weeks so the overheating soldiers in the NSW Corps could swap their heavy winter uniform for the summer uniform earlier.

So not only have we been burdened by the unquestioned adoption of the northern hemisphere's four seasons, our spring, summer, autumn and winter were shuffled forward to meet the excesses of a military uniform designed for British winters.

We have modified laws, language, social structure and government to suit our own purposes, and one day we'll rid ourselves of British royalty, yet we accept the mother country's seasons without question.

Or you do. For a long time I have believed that I was Nigel No Friends in questioning, as longtime readers may recall, why we have just four official seasons, why they are of the same duration, why they begin when they do and why they should apply uniformly across a country of impossibly varied climate.

But I am Nigel Two Friends. On Saturday, I have just read, a guest speaker at a garden and market day in Pymble in Sydney outlined his case for five seasons, and that speaker was no less than the chief of Sydney's Royal Botanic Gardens, Tim Entwisle. And at Seaham the founder of Nature Watch and a retired lecturer in biological and environmental science, Kevin McDonald, agrees with him.

Dr Entwisle argues that the four seasons we have inherited from the northern hemisphere just don't fit our bill, and to illustrate this he points to the fact that the flush of flowering begins in and around Sydney in late July or early August. So he is proposing five seasons for the lowland coastal strip that extends north and south of Sydney and which includes Lake Macquarie, Newcastle, Port Stephens and, on a good day, Maitland.

According to Dr Entwisle's calendar, and my own indefinable sensations, we are now in spring, which occupies August and September. Yes, just two months, like four of the five seasons, because these seasons reflect segments of the natural cycle here on our coastal strip, not somewhere in the northern hemisphere.

Next is pre-summer, in October and November; then peak summer over four months, December, January, February and March; autumn in April and May; and winter in June and July. It does seem ludicrous that November is classified now as spring, that March is autumn.

Mr McDonald, who has been keeping daily records of his nature observations for many years, agrees with Dr Entwisle by and large. He points out that Aboriginal people had five, six or seven seasons that reflected the natural sequence in their region rather than another hemisphere.

Our region has six months of hot weather, Mr McDonald says, and that assessment fits neatly with Dr Entwisle's six months of pre-summer and peak summer. Mr McDonald co-ordinates a project, Nature Watch, that involves a loose group of people interested in observing the natural world (kevinmcdonald@hotkey.net.au if you're interested), and their records establish that while some things in nature are changing with changing temperatures, others that rely on daylight length are not.

Dr Entwisle has a fallback position. If we must stick with the other hemisphere's seasons he suggests we mark the start of critical periods in the botanical cycle, periods that will exist despite our unwillingness to recognise them as seasons.

Wattle Day on September 1 would have to be moved back to a date that more widely reflects the start of wattle's flowering, August 1, then we'd have Telopea Day on October 1, Hyacinth Orchid Day December 1, Banksia Day April 1, and Grevillea Day June 1.

We could do with more colour in our lives."

Image: 'Plant of the month' for August at our Mount Annan Botanic Garden. The wattle garden is spectacular at the moment, signally the start of spring.

It's Spring!

Would these magnolias in the beautiful gardens of 'Claremont' in Pymble be flowering if it wasn't spring? Would the wattles be in full bloom across south-eastern Australia to the degree that the cabbie in Canberra tells me it must be spring, if it wasn't? What are the hardenbergias and boronias flaring purple in the bush for if it isn't spring?

Well there are a few responses to this of course. Firstly, perhaps, one wattle/magnolia/boronia does not a spring make. Then, there's plenty of other things not in flower. And on to, it's different for me because I live in Katoomba/Hobart/Darwin. And so on.

Of course 'seasons' vary across the country and the vary from year to year. But as I say every year, we don't have an early spring this year in Sydney, we have the usual start to our peak flowering season, in August.

So what to do about it? I've argued for a rewrite of our seasons - see specifically my suggested Seasons for Coastal Sydney or a few other mentions here.

Today I spoke on this topic at the Easy Care Gardening Garden & Market Day at the lovely 'Claremont' home in Pymble. I outlined my case for five seasons - spring (August, September), pre-summer (October, November), mid-summer (December, January, February, March), kind-of-autumn (April, May) and winter (June, July).

You've got to agree that it's appealing to have two months for winter and four for summer! But seriously, the seasons in most of our regions don't, and shouldn't, be the same as the old country. The trouble is that head just 100 km inland (and upland) from Sydney, my system won't work properly - for a start they have real autumns. And then there is the problem of temperatures and the like (climate) having cycles slightly different to the plants (which use day-length as well as water availability and temperature).

In any case I said today, as I've said before, that if we can't change the seasons let's at least celebrate the start of critical times in the botanical cycle. The first thing to do would be to move Wattle Day to 1 August rather than 1 September. I'm aware of the history of this day and that it was proclaimed nationally in 1992 to be 1 September, but...

I got some feedback today that Wattle Day is still celebrated (as it was more or less officially between the two World Wars) on 1 August in places like Orange.

It's a discussion we need to have. Before we can talk about changes in our gardens or the bush due to climate change, let's sort out our seasons or at least the recognition we give to the long-standing cycles that we live with every year.

Image: From the garden of 'Claremont'. For more about Easy Care Gardening see their website. Easy Care Gardening Inc. is a community based (not for profit) group assisting elderly and disabled pensioners to stay in their homes for longer. The support is through teams of volunteers weeding, mulching and pruning gardens. It's well worth supporting.

A Poetic Visit to the Macarthur Region

Today I inspired a poem after speaking to about 180 students in the Macarthur Region. Really.

The Macarthur Chronicle, the local paper of the Cambellton-Camden-Wollondilly area has set up what they call the Inspire Program to encourage young people in the region 'to follow their dreams'. The paper wants to address the negative stereotyping of kids in the area, exacerbated recently by publicity following the Rosemeadow riot.

Guest speakers are invited to visit secondary schools in the area, where they talk about how they got into their particular field and why its interesting. I was invited to speak today to year 10 and 11 students at the co-ed Broughton Anglican College at Menangle Park. It's partly about me imparting some inspiring words, and partly a chance for me to meet children from the school.

I talked about liking maths and science at High School, but also history and writing, and that typing was one of my favourite subjects in the first few years! It was tough dropping all but physics, chemistry and maths in Year 12, but in those days if you could do science you did science (and science only). Then into my well-worn story about starting university doing mostly maths and physics but switching entirely to botany in second year after being excited by a large picture of a plant cell (in the one small botany unit I did in first year).

From there I talked about getting hooked on algae and eventually botanic gardens. I showed some pictures of our three botanic gardens, with a particular focus on their local garden, Mount Annan Botanic Garden. They were intested in our plant for an Adventure Garden, a pump track and the enduro track (the latter two involve mountain bikes). I also mentioned the expanded Seedbank project, PlantBank. Finally a few of the more intriguing plants and plant stories, and a little about the kind of jobs we have at the Botanic Gardens Trust and what quals you need to get them.

Macarthur Chronicle will write up a story about the visit, but there's more. The biggest surprise, to me at least, was the reading of a poem written while I speaking. It was composed by staff member Charlie Dunn who regularly whips up a poetic response to talks and events. Perhaps it gives a more honest summary of what I said:

Ode to Entwisle

Doctor Entwisle, a scientist
Now director of Sydney garden is on his list.
He is in charge, he is the man
And now he’s visited Broughton Anglic - an

At botany he earned his degree
He studied microscopic, tiny algae.
A whole new algae he did discover
A whole new algae like no other.

Algae may to some be slime
Colours of brown to green and lime.
Some are good and some are bad
You can tell if pollution has made a creek sad.

1816 was the botanic garden’s birth
In a beautiful part of God’s great earth.
On Sydney Harbours edge
You can go to picnic, you can go to veg

Mount Annan, Mount Tomah, botanically new.
There is so much to see and do
Botany takes in from tree to thistle
We thank you for coming, Dr Tim Entwisle.

© C. Dunn
Friday, 7 August 2009

Image: One of the pictures I used in my talk, a paper daisy display at Mount Annan Botanic Garden photographed by Jaime Plaza.

Darwin's Descendents - The Exhibition

Charles and Emma Darwin had ten kids, but this exhibition isn’t about them, or his great-great-grandchildren. It’s about Charles’ scientific descendents – thousands of scientists working around the world on what I like to describe as the Great Adventure. Here are some notes from a speech I gave at the opening of the exhibition on Monday. What I can't provide is a transcript of Charles Darwin, in person, talking to four of our enthusiastic scientists...or Robyn Williams, both funny and smart, as always.

In short, Charles Darwin made sense of life on earth. Before Darwin, and Alfred Wallace, life was unexplained, and through this celebratory year (see plenty of postings below) I’m become more impressed by the man and his science, not less.

Natalie Angier in her book ‘The Cannon - The Beautiful Basics of Science’ – laments that we use the word Theory for his great discovery. In common parlance a theory is mere conjecture. In science, it’s about as close as we get to an indisputable fact.

What we do today is fine-tune the theory – just as we do with the Big Bang, Plate Tectonics, Climate Change….Capitalism?

Darwin spent most of his life experimenting, observing – before and after he published his theory. There was much more he wanted to check to resolve, he knew there were details to sort out.

One of those details was DNA. Another was to find more of the leaves on the tree of life (the variety of life on earth today) as well as the many more leafless branches – 99% of the tree – (the dead-ends, some of them preserved fossils).

What you can see around us today is the continuation of the great adventure started by Darwin. I know that when I dip my hand into freezing water in south-west Tasmania or the clear blue streams of Kakadu, I am entering a new world. When I return to the lab the discovery continues and each new collection adds to the story, the theory, the fact…

But my collecting has been pretty tame, except for a few crocodiles (which were mostly in my mind only). In our exhibition you’ll hear about head-butting a grey nurse shark, being covered from head to foot in ticks and parking the four-wheel drive on top of a critical specimen (haven’t we all done that, or discovered something new when relieving one’s self behind a tree…). Mind you, the exhibition doesn’t include the dangers of pipettes, or the reputed internet addiction (listen to recent episodes of Robyn William’s Science Show on Radio National).

Everyone in this exhibition is collecting, accumulating information, building up the picture. The scientists are finding new things, constructing new branches, fine-tuning the tree of life.

Perhaps 95% of fungi (150-250K, 5K described) are still to discovered, described and named; 20% of algae (12,000, 10,000 described); and 10-15% of green plants (21,000, 18,000 described), and some very serious trimming and grafting to do in all groups as we track down their DNA history.

In the exhibition we have three Trees of Life in the exhibition.

Firstly the original version drawn by Charles Darwin - which our PR Manager Kerry Brown describes as like a small piece of seaweed washed up on the beach

Then Ernst Haekel’s version drawn a decade later that looks more like a brown kelp growing on the sea floor, again thanks Kerry…

And thirdly a recent version by David Hillis (see image above) that could be a town plan for Canberra. Kerry points out humans are one shelf in one house in one street on the outskirts of that town. Try and find humans – you’ll need to use our magnifying glass if you look at the enlarged version of this ‘wheel of life’ in our exhibition. (Just one point of clarification though. About 3000 organisms are dotted around the edge of this tree/wheel and there is a disproportionate number from groups such as the green plants – the greatest diversity at higher taxonomic levels are in the protist and bacterial groups, the micro-organisms. Remember the quote I’ve used before: life to a first approximation is unicellular.)

And what does the real tree of life look like? More like the last, but more complicated still, with interconnections particularly back in the early years of algal evolution. And maybe there is another tree elsewhere in the universe, or as Paul Davies has pointed out, in some difficult to collect place on earth like a volcano or in the upper atmosphere. Now there will be some dangerous and interesting field trips, and a truly great adventure.

"Darwins Descendents: 200 years of scientific adventures", Monday 3 August – 24 November, Weekdays 10 am – 4pm. Red Box Gallery, National Herbarium of NSW, Mrs Macquaries Road, Sydney. Enquiries: 9231 8111. Entry is free.

Image: David M. Hillis, Derrick Zwickl, and Robin Gutell, University of Texas. http://www.zo.utexas.edu/faculty/antisense/DownloadfilesToL.html

Spitting Pollen

In the ‘isn’t nature amazing’ category, this plant has a clever and surprising trick to make sure it gets pollinated – it spits it on the visiting bee (or finger...).

Anneslea fragrans is not uncommon in the mountains of southern China through to Thailand, but you won’t see it in many gardens in Australia. It’s in the tea family, Theaceae, of which Camellia is the largest and most well know member. I was lucky enough to see a mature plant at Bob Cherry’s Paradise garden on Saturday, and to have its tricky pollination mechanism demonstrated to me.

You can see the pollen ‘spittle’ on Bob’s finger in the first picture above. The young flower has its petals tightly clasped together, forming something like a Russian church spire. The swollen part of the spire has slits in it to allow the perfume (it’s not called ‘fragrans’ for nothing) to escape, attracting pollinating insects such as the bee. You might be able to see the slits more clearly in this image.



So then the bee, or Bob’s finger, hovers around the fragrant bloom. If the tip of the spire – a protruding ‘style’ I think – is knocked in any way, a blob of pollen fires out the nozzle. The shocked and now pollen coated bee moves swiftly to a new bloom. This time it may be an older flower, fully opened and receptive to the smear of pollen that will be left on its style.

That seems to be the way it works. It’s fascinating to see the plant in action and we must get an Anneslea on display in the Royal Botanic Gardens (or at least I should find out if we have one at Mount Tomah).

A Few Glimpses of Paradise

Today and tomorrow is open day at Bob Cherry's home garden 'Paradise'. I mentioned this garden in my posting about Derelie Cherry's beautiful new book 'Two Dogs and a Garden' but today I can provide a few pictures.

Bob Cherry showed us some of the gems in the collection, particularly Camellias from China and thereabouts. As always he would gather enthuisiasts as we swept (or more accurately, meandered) through the garden.

Here are a few more pictures from today, the first two Camellia amplexicaulis, a species we had in (single) flower a few weeks ago in the Royal Botanic Gardens.

And Bob in action...

More on Mr Darwin

I should have added to my last posting the link to more information about our Darwin calendar for the year - here!

The Science Open Day mentioned is more precisely 10 am to 4 pm on 23 August (i.e. not 23 and 24 August).

But first...starting on Monday, come look at what Darwin's scientific ancestors are doing in Sydney. See how they risk life and limb to collect plants, then grind them up to extract long 'sentences' such as TACGAATTCCGATGACAC... - sentences without punctuation and using only four letters, but the code of life.

Visit the Red Box Gallery, to your left after you cross the Cahill Expressway on Mrs Macquaries Road.

Darwin's Garden (P4P*)

In his later years, Charles Darwin experimented and observed nature in his backyard and glasshouse ‘laboratory’ at Down House in Downe, England. He studied pollination, climbing vines, insect-eating plants, and famously, earth worms, among other things.

His other ‘garden’ was the entire flora of the world, as observed and collected during the voyage of the The Beagle between 1831 and 1836. After the publication of The Origin of Species in 1859, this garden of creation became the garden of evolution.

This year we have been celebrating the 200th birthday of Charles Darwin and 150 years since the publication of his famous theory of evolution by natural selection.

One of the things we’ve tried to emphasise here at the botanic gardens – and you can see a reference to this in the quotes adorning our D-A-R-W-I-N installation – is Darwin's abiding interest in plants generally, and his particular love of animal-eating plants and orchids. (The picture above is the back of the letter ‘D’, featuring Darwin’s head!).

Darwin once said 'I care more about Drosera [the insect-eating sundews] than the origin of all the species in the world'. Perhaps a little hyperbole, but for someone who wasn’t all that taken by the Australian flora he fell in love with a genus of about 180 species, more than half of which are native to our country (mostly in south-western Australia). (Although he said he looked forward 'with more pleasure to seeing Sydney than to any other part of the voyage', he left saying famously 'I leave your shores without sorrow or regret’.)

He also said 'I never was more interested in any subject in my life than this of orchids'. Clearly he'd forgotten all about his sundews, but orchids certainly gave him lots of evidence for evolution and he published a major tome on how orchids and insects help each other, called The various contrivances by which orchids are fertilised by insects.

Those contrivances included trigger mechanism to bash the head of the insect against ready waiting pollen, buckets to trap the insect and direct it past the pollen, and long nectary spurs that require the insects to dip their head deep in the spur to get the sugary reward, thus....past the pollen again. Actually the pollen in orchids is glued together in a big lump called a 'pollinium', which can found attached to various appendages of your recently visiting insect.

Most famously, Darwin predicted the existence of a moth with a 30 cm long proboscis (straw-like device for sucking up nectar) after he saw an orchid from Madagascar with a 30 long nectar spur. 41 years later, and after his death, such a moth was discovered.

Here in the botanic garden you can walk along our Thinking Path, reading and contemplating the quotes about evolution. Every tree in the botanic garden can remind you of the tree of life, with the leaves representing species alive with us today.

It’s worth remembering, though, that most species are extinct, and most of life is unicellular. That is, to continue the analogy, most leaves have fallen off the tree and only a few of these leaves represent the flowering plants and largish animals we see around us every day.

And to learn more about Darwin and his legacy, visit the Darwin’s Descendants – 200 years of scientific adventure exhibition in the Red Box Gallery, on the left past the Art Gallery of NSW, from August 3 until November 24 (weekdays 10 am to 4 pm, free entry). There will also be Science Open Days at the Gardens on the weekend of 23 and 24 August 2009.

The back of the letter ‘D’, featuring Darwin’s head, and the first letter in the DARWIN installation at the Royal Botanic Gardens]

*This Passion for Plants posting will also appear on the ABC Sydney website (possibly under 'gardening'), and is the gist of my radio interview with Simon Marnie on Saturday Morning sometime between 9-10 am on 702AM.

Local Governments, Roses and Irises, and Why Not?

I’m feeling very close to local government at the moment, as long as it’s someone else’s local government.

Last Monday I was in Grafton to help celebrate 150 years of local government for the Clarence Valley. I attended a reading of the original Proclamation – well part of it – followed by a Mayoral reception with plain and pumpkin scones.

I missed the opening of the Shannon Creek Dam due to my inability to follow simple, but easily misconstrued, instructions about how to find the dam. But I did make the Celebration Dinner at the South Grafton Ex-Serviceman’s Club, including the launch of a book about the last 150 or so years in Grafton.

The Botanic Gardens does have some interesting associations with Grafton. The locals made the brave decision to ask our Director between 1846 and 1896, Charles Moore, to suggest trees for their new school. Director Moore of course said the Moreton Bay Fig. He always said the Moreton Bay Fig. I gather he sent them some seedling and now the city has some lovely mature specimens of this species amid an impressive collection of park and street trees. The famous Jacarandas weren’t in flower when I was there but many of the streets – such as the one pictured above – are quite beautiful.

There is another connection, with Grafton being the death place of William Carron, a collector at the Botanic Gardens and survivor of the ill-fated Kennedy expedition to Cape York in 1848. I’m sure there are other links – they have a Grey-headed Flying-fox camp for starters.

That was Grafton. This morning I spoke about the World’s Greatest Botanic Garden (yes again, and no it’s not just Sydney) at Woollahra Council building. A very enthusiastic and interested audience, in a very scenic location looking over the harbour.

This afternoon, I joined the Mayor and some councillors from Hawkesbury City Council to watch Her Excellency Governor Marie Bashir plant the first ‘Governor Macquarie Rose’ at the Deerubbin Centre in Windsor. Her rose was then flanked by plantings from Mayor Bart Bassett and Glynis Hayne, President of The Rose Society of NSW (and Australia as it happens).

The rose was bred by Trevor Grant and will be propagated and sold by Swane’s Nurseries. You’ll remember that Swane’s was also behind the Firefigher Rose planted in Government House earlier this year. This new Rose, perhaps to become know as ‘The Governor’, will grace not only every town in the Hawkesbury City area, but also (according to today’s speeches) Hyde Park, Government House and the Royal Botanic Gardens.

Today’s plantings were of course just sticks in the ground, so I can’t give you a photo of the bloom. Apparently it will be pink and perfumed and for all you rose buffs, it’s a hybrid tea.

Coming up in the new year, the bicentenary of Macquarie's reign as fifth Governor of the penal colony of New South Wales (1810-1821), the rose will be joined by a blue and white iris. Why an iris? Elizabeth Macquarie apparently had a penchant for distributing blue irises and white irises around the countryside, so a special blue & white bloom has been bred to celebrate the occasion.

We discussed at the function today the fact that both plants are native outside Australia, but then so were Lachlan and Elizabeth...

Seed Pod Art

If you like to mix your art and plants, take a look at this exhibition by Scott Cardamatis and Joseph Saad. Last night Bob Carr opened the exhibition at Global Gallery in Paddington with his usual mix of gravitas, substance and humour.

In tune with the artwork, the opening speech had a strong environmental message. And yes Red Gum forests were mentioned!

The art is constructed from various seed pods and other related plant parts, collected from around Australia, but mostly south-west Western Australia. It's all very sustainable, with most of the pods being unwanted waste from seed collectors in the west.

I won't try to describe the result. It's better that you head to 5 Comber St, Paddington, or too Scott and Joseph's very pretty website. I can say that I like it a lot.

Is this a new genre of art? I'm not really able to judge but this view was certainly proffered frequently at the opening.

So yes again I'm doing a bit of an advert, but I'm happy to promote projects that promote plants and conservation.

No Longer (Much Shorter) Under the Banyan

Two weeks ago I was on Lord Howe Island standing under this tree, what the islanders call a Banyan (Ficus macrophylla f. collumnaris - also sometimes called a subspecies, ssp., rather than form, f.').

One week ago I was standing under a 'Banyan' in the Royal Botanic Gardens in Sydney being photographed as part of a story on the botanic gardens for Sydney Magazine (the glossy that comes free with the Sydney Morning Herald once a month). Don't worry, other people were photographed as well - five of us in all - to match up with interviews we did on science, the herbarium, guided walks, animals in the botanic gardens, Indigenous food plants and so on.

The sad thing is that the picture was no good. Apparently all but one picture (of our photogenic Indigenous Education Officer - yes, you, Clarence Slockee!) has too much person and not enough botanic garden.

So as the sun set over the city this afternoon - around 4.15 pm - I was rephotographed next to the giant Children's Fig (Ficus macrophylla f. macrophylla, in case you were wondering). This time I'm pretty much a scale bar. You'll be able to see how magnificent this tree is by looking at the tiny Director standing next to it! The Banyan is still there, but now in the background, and without me blocking out a dozen or so of its magnificent trunks.

I'm assuming this will be it. The final pictures were taken in medium or large format, with film. Good old fashioned photography. The discarded Banyan and me were all digital. We'll see the final result in the September issue of Sydney Magazine. Who knows what will survive the editorial process but you can be sure that Clarence peering out from the subtropical garden will be the money shot...

A Different Kind of Commemorative Rose

Another weekend with the Armed Services. A few weeks ago it was the Reserve Forces on parade in the Domain. Today it was the dedication of the NSW Korean War Memorial in Moore Park, and there is a botanical link.

Minister Graham West (as Minister Assisting the Premier on Veterans' Affairs) was joined by Don Rowe (President of the NSW RSL, and known to us at the Botanic Gardens through the dedication of the Domain Memorial Wall and the repair of the Morshead Fountain), Mr Yang Kim (Minister for Patriots and Veterans Affairs, Republic of Korea) and other representatives of the Korean government and Korean war societies in Korea and Australia.

The botany? Well the Memorial consists of a stone wall around scattered Rose of Sharon (Hibiscus syriacus, the national flower of the Republic of Korea) in steel and bronze. Each flower represents a NSW soldier who died in the Korean Ware 1950-53. In the centre are two large granite stones from a quarry in Kapyong, a significant battle site in Korea. Eleven concrete 'blades' are interspersed with the hibiscus flowers, one for each of the battles in which Australian soldiers played an important role.

It's an impressive and evocative memorial, thanks to the design tallents of Jane Cavanough from Artlandish Art and Design, along with Pod Landscape Architecture.

You won't see many Rose of Sharon hibiscus in gardens around Sydney (although correct me if I'm wrong - I know we have grown it at the Royal Botanic Gardens in the past). Jerry Colby-Williams (in an online item from Gardening Australia) notes that 'rivalling the heat-loving hibiscus is the Rose of Sharon (H. syriacus), a cold-hardy, deciduous shrub or small tree'. I note that this follows a recommendation to visit Sydney's Royal Botanic Gardens in summer to see rare (heat-loving) hibiscus species.

It's also worth noting that the common name Rose of Sharon is also applied to Hypericum calycinum, Lilium candidum and Tulipa agenensis subsp. boissieri, being cited in a nice little article on our website as an example of how common names can sometimes mislead.

I've mentioned before the botanical connections developing between Korea and Australia. Today was a demonstration of the strong bonds that already exist between the two countries, rising of course out of adversity.

Thanks to the Landscapedia website for the picture of the Rose of Sharon.

Our Headful Ballerina

La Ballerina with some of the donors who made her restoration possible (photo: Simone Cottrell)

The following media release (thanks to Kerry Brown) tells a little more of the story just in case you missed the ABC or SBS news on Thursday night, or the Sydney Morning Herald yesterday!

Missing piece of history returns to Gardens

Once a prevailing presence in the Royal Botanic Gardens, their morality and their taste have been questioned, and their numbers diminished as they have been burned, banished and beheaded.

But the tide has turned and the historic statues of the Gardens and Domain are being rehabilitated. On 23 July, “La Ballarina” was returned to the Gardens with her new head, hand and foot.

She was one of a shipment of eight statues purchased in Italy in 1883 for the new Palace Garden in Sydney’s Botanical Gardens on the site of the razed International Exhibition Centre. Postcards of the newly laid-out garden show almost as many statues as trees.

Botanic Gardens Trust Executive Director, Tim Entwisle said, “The nineteenth century statues were integral to the early design of the Gardens and the values that inspired it. European civilisation was recreated in these young colonial gardens through classical and neo-classical artworks.”

La Ballarina was sculpted by Charles Summer, a highly successful Australian-born sculptor living in Carrara, Italy. It is a copy, albeit a good one, of a work by Antonio Canova, the most famous Italian sculptor of the nineteenth century – some say the best since Michelangelo.

After more than three decades in the Gardens stoneyard, and losing important appendages including her head, La Ballarina is the first surviving Italian marble to undergo reconstruction.
Managing Director of International Conservation Services Julien Bickersteth, who has overseen the work, said the new head, foot and hand were sculpted by Polish-born Master Jacek Luszczyk of Traditional Stone in Lidcombe, Sydney.

“Jacek worked from images of the original sculpture by Antonio Canova. The marble for the reconstructions was shipped from Carrara, the source of the original marble,” Mr Bickersteth said.

La Ballarina was unveiled beside the Main Pond, casually balancing on the toes of one foot, her graceful new fingers touching the chin of her new tilted head.

Also speaking at the unveiling, Australian Ballet Artistic Director David Mcallister said, “Dance is enormously popular in Australia, with around 300,000 people actively participating in a dance class each week. We can only imagine the joy that visitors to the Royal Botanic Gardens will experience when stumbling across the beautifully restored La Ballarina after such a long injury and absence from the stage.”

La Ballarina now stands within coo-ee of the 1995 mosaic “Wuganmagulya” by Aboriginal artist Brenda Croft recalling ancient rock carvings of the area’s original inhabitants that depict the sea, land, native flora and fauna of the place where the viewer is standing.

“The Gardens’ statuary acquired over more than 150 years provides a unique visual record of the evolving social and artistic values of Australian society,” said Dr Entwisle.

Other marble “Italians”, such as the Discus thrower currently lying broken and bound in the Gardens stoneyard, are among the statuary lined up for restoration as private donations make this possible.

Last year, five bronze monuments in the Royal Botanic Gardens and Domain underwent extensive conservation through private funding.

Paradise in the Maiden Theatre

On Friday I had the pleasure of hosting the launch of 'Two Dogs & a Garden', the latest publication by Derelie Cherry. Representatives of the horticultural media, botanic gardens staff, Friends and friends, all gathered in the beautiful Maiden Theatre to hear about a beautiful book.

Graham Ross (30 years talking gardening with wife Sandra and daughter Linda on 2GB, 15 years on Better Homes and Gardens, and previously 10 years as Trustee at the Botanic Gardens) was guest speaker, and he spoke about Bob Cherry as a quiet, but over, achiever. The book covers a lot of ground, and as Graham said, contains many parallel stories. There is the meeting and marriage of Bob and Derelie, the lives of their two dogs of course, and most prominently in the luscious illustrations, the garden!

If you don't know the garden, its quite aptly called 'Paradise' and it lives north of Sydney in a place called Kulnura (the picture above is from my visit in 2004). Bob and Derelie open the garden twice a year, and this year with an additional October opening as part of the Open Garden Scheme. The next opening is the first weekend in August. I better not do any more advertising - have a look at their website for more about the book and the garden.

But back to the launch. Derelie was the next to speak and clearly this book was a labour of love, in more ways than one. When I first met Derelie about five years ago she was encouraging me to write a book. As I said on the night, it's books like this that are so well written, designed and produced that scare me off. Of course Derelie is well experienced in the task. She has a PhD in History, researching and writing on Alexander Macleay in colonial NSW, and over 20 years experience in in publishing books. As she says in her book, she met Bob Cherry at the Melbourne International Flower Show in 1999, and was wooed with flowers and the chance to live with two dogs and a garden.

Bob also spoke, about his love for growing and breeding plants, but also for seeing them in their natural habitat. Bob Cherry has a long association with the botanic gardens. In 1990 he travelled to southern China with Carrick Chambers and Ben Wallace, where in the first of his many collecting trips they covered 5000 miles and 400 plants (if I've matched up the right trip in Derelie's book!). Bob also travelled with Karen Wilson (a couple of years earlier, to New Caledonia), and later, with staff Simon Goodwin, Tony Curry and Ross Ingram.

Together they collected lots of plants for Bob's nursery but also for the botanic gardens collection - over 1000 accessions, from China, Vietnam, New Caledonia, Mexico. A couple I mentioned at the launch were the large King Fern at the entrance to the Fernery (which Simon Goodwin tells me also came with the fern-like attached plant, Tmesipteris (a species of which I saw on top of Mount Gower on Lord Howe Island last week...) and Camellia amplexicaulis which I mentioned in a previous post.

There was also the wild-collected Taxodium mucronatum (Mexican Bald Cypress) which was planted beside Central Avenue in the Domain two years ago to commemorate the 150th anniversary of the first First Class Cricket match held in NSW (between NSW and Victoria). And for someting completely different, the yellow-flowered Nelumbo (Lotus) that, according to Simon Goodwin, became a great hit in the Cunningham Pond in the late 1990s.

So lots of wonderful plants in the botanic gardens are thanks to Bob, and later Derelie who joined him on his trips. The fact that we have a wonderful book about the garden of plants at Kulnura, is thanks to Derelie, and of course Bob.

The Cryptic House (P4P*)

This might one day be our "Octopus's Garden", just off Mrs Macquaries Point. For now, our Cryptogam House is a reminder of the alga, fungi, mosses and other smaller 'plants' that live in and around our botanic garden.

Firstly, we need to clear up the confusion between ‘cryptogram’ and ‘cryptogam’. The former is a code that requires deciphering (i.e. cryptic writing), the latter a group of plants and plant-like organisms whose sexual ways were once obscure (i.e. cryptic marriage). The term cryptogam is itself a little cryptogramic.

So why do we have a house dedicated to things with obscure sex? Well most of the botanic garden displays the beauty and wonder of ‘phanerogams’, the seed-bearing plants. In these plants you can see the sexual organs – they are the mostly the pretty flowers that attract the attention of birds, bees and us, but also conifers and the like.

The category Cryptogamia was devised by Carl Linnaeus in the 18th century, but the definitions have changed over time. Ferns, for example, have been included in either cryptogams or phanerogams. Mosses, algae and fungi have always been considered cryptogams.

But now that we understand the full complexity of life on earth, these terms aren’t very helpful, except as a link to the history of science and our botanic garden.

Mosses are grouped together with the flowering plants, conifers, ferns and green algae. The rest of the algae are incredibly diverse and spread throughout the tree of life. The fungi turn out to be more closely related to animals than to plants.

The anachronistic Cryptogam House in the Royal Botanic Gardens started life in 1921 as the Aquatic House, holding glass display tanks of water plants. It evolved into a cryptogram display, showing off mosses and ferns – plants that generally like moist but not fully aquatic surrounds.

These days it is used by our Education staff for potting up plants with some of the 24,000 school children who visit the botanic gardens for classes and excursions.

We have plans for opening up more of our glasshouses and turning a couple of them into large aquatic tanks to display water plants. You can see bigger cryptogams in the Fernery, next to the Cryptogam House.

I’m also keen to promote what might be called the ‘Octopus’s Garden’ off Mrs Macquaries Point. There is a natural aquatic garden under the sea and we are exploring ways to view and interpret the seaweeds on the rocky shores of Sydney Harbour.

*This Passion for Plants posting will also appear on the ABC Sydney website (possibly under 'gardening'), and is the gist of my radio interview with Simon Marnie on Saturday Morning sometime between 9-10 am on 702AM.

Pretty Odd Camelia

An intriguing camellia species from Vietnam is now in flower in the Camellia Garden around Rathborne Lodge in the Royal Botanic Gardens (enter via Woolloomooloo Gate).

In 2007, a snip of Camellia amplexicaulis was donated to the Botanic Gardens by camellia collector and grower extraordinaire, Bob Cherry. Our horticulturalist Phil Pettitt successfully grafted the cutting, and you can now see it in full bloom.

This species has some of the longest leaves in the genus, sometimes over 25 cm, and as the name ‘amplexicaulis’ implies (in Latin), they embrace the stems at their base. The new growth is crimson or bronze coloured.

In bloom it’s equally striking, with goblet-shaped flowers that are pink or red with a purplish tinge. Although naturally a summer-autumn flowerer, it can flower at any time, as evidenced by this photo taken last week at the Royal Botanic Gardens.

Thanks to Simon Goodwin for the image (which shows a flower a little more open than usual) and link to more background on this species.

Island Palms

Leaflets down, leaflets up...

I’m back from a short holiday to Lord Howe Island and the ‘star’ plants there are certainly the palms. The four species grow naturally here and no where else – i.e. they are endemic to the island (along with another 101 of the 243 native species) – although you’ll find one of them in gardens around the world.

There are three genera, all of them endemic to the island: two have only one species, and the best known, Howea, two. I saw them all on a walk to the top of Mount Gower.

Although both Howea species are sometimes called Kentia Palm in the horticultural trade, it’s Howea forsteriana, known on the island as the Thatch Palm, that is more widely grown under this name. The second species, Howea belmoreana, is called Curly Palm on the island.

Three botanists from London – Vincent Savolainen and Matthieu Boulestiex from Imperial College London and Bill Baker form Royal Botanic Gardens in Kew (England) – have been studying these palms in great detail over the last few years.

The Thatch (or Kentia) Palm grows from sea level to around 300 m, the Curly Palm starts a little higher (at 50 m) and grows up to 400m. The fact that the ranges of these two closely related species overlap has intrigued botanists for some time.

The London trio found the two palms had diverged from a common ancestor less than one million years ago, on Lord Howe Island. Speciation – the process of a new species being formed – has been what we call ‘sympatric’. This means, as I said above, the two species grow in the same place.

The Thatch Palm flowers on average six weeks before the Curly Palm, which may have been enough to allow them to go their separate ways. However there is enough overlap to allow cross-fertilisation. Hybrids exist on the island and you can see one in the Palm Grove of the Royal Botanic Gardens (if it has survived our flying-fox friends).

Our London colleagues continue to discover curious things about our palms. Both are wind-pollinated, even though most palms are pollinated by insects. And the Thatch Palm includes genetic variants across the island: for example, there is a distinct cluster near Ned’s Beach. These populations may well be in the early stages of becoming new species themselves.

So how can you tell a Thatch from a Curly? As the two pictures show, the former has flattish fronds with droopy leaflets. The latter has – you guessed it – curvy leaves, and quite upright leaflets (giving it an angular look). The Thatch Palm also has more than one flowering stalk at a time.

The value of the palms to the island’s ecosystem goes without question, but one local curtly noted that ‘Kentia Palm is good for producing seed to grow more palms, and that’s about it!’

[Thanks to The Lord Howe Island Signal, volume 6, number 85, 3 July 2009 for the scoop on this species.]

My Island Home (Briefly)

I'll be here for a few days, and will no doubt return with tales of its popular palms, and perhaps other peripatetic plants...

Plant Maths

I was asked a question today about links between maths and botany. Of course the architecture of all plants is guided by mathematical principles - from structural engineering to keep them upright to various constraints on growth at a molecular and cellular level.

As a young scientist (i.e. quite a few years ago) I was on the look out for ways to combine mathematics into my botanical research. I wasn't so interested in statistics or 'applied maths', but was intrigued by why plants looked the way they did and how they grow, often (as in a tree) in a very iterative way.

In the end I got diverted into the discovery and classification of plants and algae, but I've always been intrigued to patterns in nature. One of the most famous it the Fibonacci series, and I spoke about this with Simon Marnie (ABC Radio Sydney, Weekend Show) about a year ago. Given this was before I was a regular blogger, I'll copy the notes for that interview here:

"Fibonacci, or Leonardo of Pisa as he was known to his friends, was perhaps the great mathematician in Europe during the middle ages.

He was one of the first Europeans to use the 1-10 number system we enjoy today, and he asked the pertinent question ‘how many pairs of rabbits are created by a pair of rabbits in one year’.

The answer to this question led to the discovery of a sequence of numbers that now bears his name, the Fibonacci Series.

Put simply, each number in the series is the sum of the previous two numbers. So if we start with 1, we get another 1 (0+1), 2 (1+1), 3 (1+2), 5 (2+3), 8 (3+5) and so on to 13, 21, 34, 55, 89 etc.

These numbers appear with surprising regularity in botany. A well know example is the spiralling of flowers in something like a Sunflower, or the scales on a pine cone. If you stare down at the tip of a pine cone or in the middle of a sunflower you see the segments (individual flowers, scales etc.) spiralling out in two ways.

One way is called the steep spiral – these run most directly to the edge of your view. The other is the shallow spiral – these curve around and include more segments before then reach the edge of your view. The number of spirals you see in both cases – shallow or steep – will be a Fibonacci number, and the ‘steep’ will be the next number in the series after the ‘shallow’.

Two examples cited in a recent edition of Brisbane Botanics, the newsletter of the Volunteer Guides at Brisbane’s Botanic Gardens, was a pine cone with 8 shallow spirals and 13 steep spirals, and a protea flower head with 21 shallow spirals and 34 steep spirals of flowers. The sunflower can have 89 or even 144 rows of spirals (you do the maths).

All this sounds weird until you look at a flower and fruit but it will quickly come to you if you look at the real thing in your garden.

Petals on a flower are often in a Fibonacci series number: e.g. 3 in an iris, 5 in a buttercup, 8 in delphiniums. There are exceptions of course, such as a doubling of these numbers in some species.

Why is this so? It’s probably due to developmental constraints and opportunities… What that means in the real world is there are some efficient ways of packing cells and plant structures so that each unit has maximum exposure to light or pollinators or whatever.

In more precise terms, each new unit is about 222.5 degrees away from the previous one because this, on average, allows the best ‘packing.

But then some plants don’t conform entirely. There is the Lucas Series which goes 1, 3, 4, 7, 11… But really this is just the Fibonacci series starting with 1 and 3, rather than 1, 1 and 2. With some different constraints at the start, this presumably results in the most efficient arrangement of the various bits and pieces.

Botanical garden architecture is now mimicking these patterns. There is the education facility at Eden Project in Cornwall, ‘The Core’, and the new treetop walk at Royal Botanic Gardens Kew. ‘The Core’ even as at its core a 70-tonne piece of Cornish granite sculpted into a seed with a Fibonacci pattern of pimples [the photo above is the top of 'The Core']."

The Kid's Fig (P4P*)

Of the 3,000 mature trees in Royal Botanic Gardens and Domain, which is the most significant or remarkable? Perhaps the first Wollemi Pine ever planted in horticulture? But that specimen is little more than a decade only, hardly ‘mature’.

When Richard Allen, on his way to producing a book about such trees, asked me I stumbled from the Wollemi Pine (too small), to Charles Fraser’s Yellow Wood, Flindersia xanthoxyla, planted in 1828 in the Palm Grove (no-one knows about it), to the Red Cedar near Palm House that was also collected and planted during Fraser’s tenure (ditto).

Apparently the right answer is the Children’s Fig, a beautiful specimen of Moreton Bay Fig on the west side of Farm Cove. I know this because previous Director, Professor Carrick Chambers, did some recognisance work with a few other staff before he brought Richard’s question to me.

They were right of course. There are about 500 figs in the Royal Botanic Gardens and Domain, 150 of them Moreton Bay Figs (Ficus macrophylla f. macrophylla). Quite a few of them compete for the title of remarkable, including the one just below the Morshead Gate and another trapped on the island in the middle of Mrs Macquaries Road.

One Moreton Bay Fig, though, is so special we’ve built an impressive green fence around it. We don’t know the age of the tree but it is presumably one of Charles Moore’s many fig plantings. Moore was director of the Gardens from 1848 to 1896, and according to the director of the Museum at the time, had a ‘predilection for that scourge of gardens, the Moreton Bay Fig’.

Trust Community Education Officer, Donna Osland, tells me that the tree got its moniker on Arbour Day in 1983, when the Plunket Street Public School pupils were designated its custodians. At that time, children loved playing in its buttress roots and aerial root trunks.

For safety reasons, kids now have to slouch on the fence and dream about such play. Still, it’s an impressive tree and – along with the Wollemi Pine, Yellow Wood, Red Cedar…and perhaps the Chrysophyllum imperiale planted by Prince Alfred in 1868… – it is one of the most remarkable trees in the Gardens.

*This Passion for Plants posting will also appear on the ABC Sydney website (possibly under 'gardening'), and is the gist of my radio interview with Simon Marnie on Saturday Morning sometime between 9-10 am on 702AM.

Weird Life

I was fascinated, as always, to hear Paul Davies talking about the origins of life, this time on Radio National's Science Show. It was a great show all round - part two of a fascinating astronomy special linked to the Music of Cosmos event staged by University of Sydney.

Davies, now at Arizona State University but based in Adelaide for a while in recent years, was talking about what he terms 'weird life'. He thinks finding life elsewhere in the universe is unlikely, or at least not to be necessarily expected, but worth investigating.

He makes a good point about not confusing the number of earth-like planets with the number of planets that have earth-like-life, or indeed any life. There is more to life starting and evolving than finding 'goldilocks' planets like ours - i.e. just right in terms of having water and being a goodly distance from a star.

But more interesting are his ideas for testing here on earth for 'alien' or 'weird' life. What he means is that there may be life that has evolved separately to all the bacteria, bugs, algae, flowers, fungi and people that populate this planet. If such life could be found then we might argue that if it can happen twice on a near-perfect planet like ours, it could happen elsewhere. If not, well we go on searching.

It's complicated of course and this weird life might be living in extreme environments were regular life can't live - e.g. very, very hot places; very radiated places; very acidic places; and son on. Or it might live just under, or as Davies puts it, even in, our noses.

An obvious question is even if we find such weird life (with perhaps different DNA, different amino acids, different chemical symmetry) how do we know it isn't just an off-shoot of the same family tree during a long experimental phase at the beginning. There are tests for this but it does depend on life beginning with a bit of a bang rather than a draw out fuzzy period. And of course the weird life might be extinct now so we need to also search through historical remains of life.

Download or listen on-line to this Science Show (and while you are at it, the previous one - these astronomers and astrobiologists are exciting presenters). It's definitely a feast for the brain.

Maybe I'm more interested in this kind of thing because I work on relatively weird life - that is, algae - but I think the diversity of life forms on earth, and the way they evolved, are fascinating.

By the way, my picture is of a bromeliad, Aechmea gamosepala, which is coming into flower at my front door at the moment. Not necessarily weird life, but weird looking.

Reservists on Parade

Looking after the Domain as well as three botanic gardens means there is a lot more to life than plants and horticulture (in fact within the botanic gardens there is more as well but the Domain is different).

Today there I sat with senior soldiers, politicians and other dignatories to watch the Vice Regal Review of the National Reserve Forces Day Parade. Another gorgeous morning in Sydney, as the '39ers' (reservists serving during the Second World War) were honoured first, then various brigades of service people.

The NSW Governor and NSW Patron of the Reserve Forces Day Council received a Royal Salute then inspected the parade, before saying a few words of welcome and thanks. This year is 70 years since the start of the Second World War, an opportunity to thank the many people in the reserve forces back then, and today.

The event went like clock-work, in true military style. Very formal and respectful, as it should be, but also very powerful when you scan the faces of those who served during wars between 1939 and today. For a civilian in a suit, very humbling.

Seductive Succulents

A beautiful sunny morning in the Cacti and Succulent Garden at the Royal Botanic Gardens. Lots of red, orange and yellow Aloes in flower. A couple of giant Agaves giving it their all in a once in (their) lifetime floral display. The giant agave-like Furcraea is nearly spent but you can find a few shattered flowers at its base, the result of cockatoo pruning.

Jaime Durie and crew had flown across to Sydney to do two days filming for their American version of 'The Outdoor Room'. It's a commercial show, but I'm happy to promote products that excite people about plants and gardens. Jamie is also an Ambassador for our Royal Botanic Gardens Foundation, and has given his time freely to help us launch various campaigns.

We talked about his return to the Cacti and Succulent Garden after quite a few years - he now spends about half his time in the US and half in Australia. Of course we also filmed and talked about his recycled steel sculpture in the Garden, and how the plants have settled in nicely after five years. It does look good, and the rusty brown finish is a great backdrop for the grey-green succulents, some with suitably red-brown new growth.

After chatting about changes in the Royal Botanic Gardens over the last five years - new Begonia, Rose and Camellia gardens, plus a reduction in the amount of water we use by about 50% - I left Jamie and entourage to walk across to the Australian Rockery, near the Opera House. This rockery is actually due for a 'make over', and we are keen to use wild-sourced plants from the NSW Seedbank at Mount Annan Botanic Garden, at the same time promoting Mount Annan near one of our most populated Garden Gates.

By the way, while I'm plugging RBG on TV, Graham Ross featured our Tropical Centre display of carnivorous plants on Better Homes and Gardens last night. A selection of our animal-loving attractions were at the top of his list of weird and wacky plants.

Stinky solution for bloody canker

Garlic sprays are popular for gardeners wishing to use less refined products to control their garden pests. Garlic is mixed with water - sometimes with chilli, onions or soap - and applied to leaves to control unwanted visitors such as aphids.

It's always nice when home-grown remedies such as this receive a tick from scientists. As someone of sceptical disposition I always seek extraordinary evidence for extraordinary claims, but garlic is a known antibacterial agent so it's no wonder small bugs don't like it - although technically it could help protect them from any irritating bacterial diseases and make leaf-munching more pleasant!

In a report in the latest issue (July 2009) of the The Garden, the magazine of the Royal Horticultural Society, it seems that giving garlic to your plant intravenously may also be good for its health. 'Bleeding canker' is a foul-sounding name for a nasty disease of Horse Chestnuts (Aesculus hipposcastanum). Since the 1970s, England has lost some of its majestic old Horse Chestnuts from this bacterial pathogen. (Although bleeding cankor has sometimes been attributed to the fungal-like Phythophthora, this recent epidemic seems to be bacterial.)

The 'blood' is the blackened gum that oozes from the bark of diseased trees. If the canker makes it all the way around teh tree, it usually dies. The article quotes Forestry Commission statistics of up to 3000 infected Horse Chestnuts being felled for public safety. '...trees start to bleed one year and are dead the next...'

A new treatment from the Netherlands would be a breadth of fresh air, except that the leaves end up smelling strongly of garlic! But the good news is that an injection of allicin, extracted from garlic, has helped trees recover within a year. The garlic in the leaves isn't really a problem either as it helps to repel moths that don't help the problem by defoliating the Horse Chestnuts.

Until now the recommended treatment was to do nothing. Cutting off infected limbs can create new entry points for the bacterium and will help spread the disease. And no antibacterial chemicals have been available for use in home or amenity gardens.

It's worth the odd whiff of garlic if you can save a tree.

And the picture? It's a Dracula orchid in our Tropical Centre...sorry...

Close to the top

In an April posting, I profiled one of more intriguing plants in the Royal Botanic Gardens, Macdougall’s Giant Century Plant (Furcraea macdougallii). It was coming into flower for the first time in our garden.

Now in full flower, Senior Horticulturalist Dawson Ougham cut a side branch of the inflorescence with a pole saw and took a lovely close up of the flower (above).

It's a good time for flowers in the Agavaceae family and around Sydney at the moment you'll see plenty of the giant, bendy Agave attenuata, also from Mexico but from higher up the mountains.

Them seeds is back

Don't tell anyone, at least until after 10.00 am today (Monday 29 June), but we've tested our space seeds. And the results are...contained in the following Media Release...with a few additional comments from me at the end...

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NASA astronaut Gregory Chamitoff today announced that the first Australian seeds to go into space have survived more than 2800 orbits of the Earth with no signs of space fatigue or damage.

At the request of the Botanic Gardens Trust Sydney, Dr Chamitoff took the seeds of Golden Wattle, Flannel Flowers, Waratah and Wollemi Pine with him on the Discovery Mission STS-124 that launched last May.

The Canadian-born astronaut and the seeds spent six months at the International Space Station (ISS) 400km above the Earth before returning in late November. An identical control package of seeds was stored back on earth.

Dr Chamitoff said “Germination tests at the NSW Seedbank at Mount Annan Botanic Garden have confirmed that space travel did not adversely affect the viability of the Golden Wattle, Flannel Flower or Waratah seeds. Germination tests are still underway on the seeds from Wollemi Pine.

“Both the seeds and I were subject to microgravity and low-level ionising radiation. NASA keeps a regular check on how I am affected, and the Botanic Gardens Trust are testing the seeds and will continue to monitor the seedlings,” said Dr Chamitoff.

The ISS, circling the Earth once every 90 minutes at 28,000 km per hour is, in effect, in free fall. Gravity is close to zero and is called microgravity. Ionising radiation is from high-energy waves at the short-end of the electromagetic spectrum which, while useful in many areas of medicine and research, can cause burns, cancer and damage to living tissue and genes.

Dr Chamitoff said, “From NASA’s perspective, we are interested in seeds that might be hardy enough to survive long duration exposure to the space environment and then germinate in greenhouses in Space or on other planets. Ultimately, this will be essential to support self-sustaining outposts or colonies in Space with food and oxygen.”

Botanic Gardens Trust Executive Director Dr Tim Entwisle said, “With habitats under increasing threat, seedbanking on earth, and perhaps in space one day, will be part of an integrated conservation program for species threatened by extinction due to global warming or other sudden changes to their habitat.

“The more we learn about how seeds react in different environments, the more we learn about how to conserve our irreplacable plant species,” he said.

Dr Tim Entwisle said that testing and observation of all four species that have endured six months in space will continue at the NSW Seedbank to see if the space seedlings match or surpass the vigour and longevity of their control counterparts further down the track. The seeds that they produce will also be compared.

“Microgravity alone has the capacity to discombobulate a seed so it doesn’t know which way to grow. Certainly this would be an issue for the seeds if they had been germinated up in Space but it seems, at this stage, that our seeds still know which way is up!” he said.

Differences in the lifespan between the space and control seeds are currently being tested using “fast track aging”. Seeds are put under tough conditions with high humidity and heat of 45 degrees, to then judge whether their natural lifespan has been shortened by their space experiences.

Dr Entwisle said, “The four species of seeds that we selected to send into space are very different from each other. The tough guys are the Golden Wattle, from the acacia family, which rely on fire to germinate and are thought to be the longest lived seeds on earth – some acacia seeds will last hundreds of years in storage. Waratahs and flannel flowers will last for decades. Wollemi pines are still a relatively unknown quantity, but this space experiment will increase our knowledge about this rock star of the plant world.”

It is hoped the Wollemi space seeds will germinate within a few weeks. Because the ancient species appears to have evolved in cooler climate conditions millions of years ago, the seeds needed to be chilled before germination.

Horticultural students from the University of Sydney assisted staff with the tests.

---

This is a case in science where 'no result' is a good result. We expected and hoped space travel would not change our seeds and so far that seems to be the case.

It's good news for a seedbank in space (unlikely in the short-term), carrying seed into space for vegetating new worlds or space stations (possibly sooner) and for the environment and seedbanking back on earth (where we need seeds to be as resilient to change as possible!).

The Acid Test (P4P*)

A pink-flowered Hydrangea in the Royal Botanic Gardens, presumably responding to a shortage of aluminium: Photo Jaime Plaza

Most gardeners know that increasing the acidity of soil can change the colour of some hydrangea flowers from pink to blue. It doesn’t always work though, and that’s because there is more to it than acidity.

Yet at a cellular level, flower colour in some plants is controlled simply by the quantity of pigments and the pH (acidity) at which they are stored. Different plant species produce different kinds of pigments, with pinks and blues mostly due to a group called ‘anthocyanins’.

These anthocyanins are stored in storage compartments in the cells called vacuoles. They slosh around in an acidic solution inside these compartments. If the acidity of this solution changes – which can be caused by a genetic mutation effecting pH regulation – the colour can change.

For example, just recently (Science 5 Dec 08) variants of petunia were bred (by fiddling with genes in a laboratory) with a less acidic vacuole solution. Even though the pigments (the anthocyanins) remain in the same concentration, this change in acidity led to a change in colour – in this case from pink to a kind of blue-purple which is not found in nature.

But back to hydrangeas, and changes to acidity on a coarser scale. The flowers of most larger-leaved hydrangeas (e.g. Hydrangea macrophylla) are blue or pink, depending on whether aluminium is available in the soil. If yes, the flower is blue. If no, the flower is pink.

The intensity of the colour depends on both the amount of aluminium available in the soil, and the amount of pigment in the flower (if there is no pigment, the flower is white). Often gardeners adjust the acidity of the soil to change the colour of hydrangea flowers. This is because aluminium is more available to the plant in lower pH (i.e. more acidic, below ‘6.5’) soils. If there is plenty of aluminium in the soil anyway, acidity might not make any difference.

Typically a gardener will add lime to the soil to make it more alkaline, leading to less available aluminium, and all other things being equal, pink flowers. But if the soil is packed full or aluminium or naturally acidic you may kill the plant (e.g. from a shortage of available iron) before it produces pink flowers! If you want blue flowers, adding aluminium sulphate (sulfate) to the soil should do the trick.

Why aluminium and not just acidity like the petunia? In the case of the hydrangea, the aluminium binds directly with the anthocyanin to create a blue coloured compound. Inside the Petunia flower the anthocyanin is changing colour due to the direct effects of acidity, but that’s beyond what we can cover on a Saturday morning – and I’d have to do a lot more homework.

Not all hydrangeas respond to fiddling with the soil chemistry. For example the oak-leaved hydrangea – Hydrangea quercifolia – has white flowers, with a tinge of pink. Nothing you can do to these flowers in a garden setting will give them even the least flush of blue.

Maybe the vacuole in these petals is too well buffered, or maybe the pigments are of a kind that is not influenced by acidity. In any case, you won’t be able to change their colour with a hand full of lime or ammonium sulphate.

*This posting will also appear on the ABC Sydney website (possibly under 'gardening'), and is the gist of my radio interview with Simon Marnie on Saturday Morning sometime between 9-10 am on 702AM.

The fruit fly of the plant world

A tiny plant with a big name? I don't think so. This image is from the Nature site.

I was amused to read the headline and lead sentence for a story on the latest genetic mapping of Arabiodopsis thaliana. This is the non-descript plant from the Brassicaceae family (once known as the Cruciferae, and including agricultural staples such as cabbage, turnips and canola), which has been analysed and manipulated in much the same way as the poor old fruit fly.

The story from the Carnegie Insitution for Science was headed 'Midget plant gets makeover'. So I immediately thought it must be about one of the really tiny flowering plants, such as the floating Wolffia - is this still considered to be the smallest flowering plant I wonder?

The start of the next line made it even more obscure: A tiny plant with a long name... Ah, one of the long named plants. You may recall I posted about this a month ago. So was it Ornithogalum adseptentrionesvergentulum?

Turns out it is neither a very small plant or a very long named plant. It's good old Arabiodopsis thaliana! But when you have to think of a new lead every time something new is discovered in this plant, it's must be a struggle.

In any case, the news item reiterated that this plant has 'helped researchers from over 120 countries learn how to design new crops to help meet increasing demands for food, biofuels, industrial materials, and new medicines'. Everything you ever wanted to know about the insides of Arabidopsis can be found in the Arabidopsis Information Resource (TAIR). Apparrently this site gets a few more hits than my blog - averaging over 1.6 million each month....

And the big news? The latest version of the full genome of this species has been released with stacks more information about the 33,518 genes that 'make up this tiny plant'. In case you are wondering, that's 114 new genes as well as 168 new 'pseudogenes'.

Arabidopsis was the first plant to have its genome sequenced. It's loved by experimental biologists because it grows fast and reaches maturity quickly, just like the fruit fly.

Watering Australia's capital botanic garden

Water for Canberra’s botanic gardens?

In good news for the Australian National Botanic Gardens (it’s been getting a bit of a hammering in the local Canberra press of late), a $3 million pipeline will carry water from Lake Burley Griffin to the botanic gardens.

Some of the concerns raised in recent days were about the impact of the drought on the living botanical collections. The new pipeline will, according to the National Capital Authority, ‘save the gardens thousands of dollars each year’. More water and more money will hopefully help restore some of the garden beds, and of course this is an environmentally responsible way to get water.

Apparently the lake water is shared between ACT and the Commonwealth. Under this new arrangement, ACT will reduce its annual take from the lake, allowing the Authority to increase the amount available to the Australian National Botanic Garden (a Commonwealth funded facility).

Most Australian botanic gardens are looking into alternative water sources, as well as reducing their water use through mulching, smarter planting and selective watering.

At the Royal Botanic Gardens and Domain in Sydney we’ve reduced water use by 50% over the last six years, Mount Tomah Botanic Gardens is totally self-reliant (dams and rainwater tanks) and Mount Annan Botanic Garden was awarded a 4-star rating by Sydney Water for the water saving initiatives over the last few years. The next big step is to get the Sydney estates hooked up to a treated storm or sewage water system – by 2016, our bicentenary, at the absolute latest!

[Thanks to ABC Online and Murray Fagg for the Canberra component of this story.]

Colourful camellias

Just a quick alert to a walk and talk this weekend by our volunteer guides.

If you like Camellias (Deborah Cameron suggested this morning on 702AM it was about 50:50) consider dropping in to the Royal Botanic Gardens at 2 pm tomorrow - Saturday, 20 June.

Helen Hemphill and other volunteer guides will tell you all about 'Camellias - Winter Beauties of the Garden'. You can enjoy tea, made of course from Camellia sinensis leaves, and enjoy the many species of camellia in flower at the moment.

Of particular interest are specimens grafted by our horticultural staff, including the 'Azalea Camellia' and a yellow-flowered species, and lots of native species from China, Vietnam and nearby. You'll also be able to see Camellia oleifera, grown more widely in China than the tea camellia due to the demand for its seed oil.

It's been a great year for camellia flowering, and with the recent rain you can enjoy the blooms on and off the bush - the carpets of pink flowers are spectacular.

The walk/talk costs $15 epr person, including the tea, and you can book through 9231 8304. It starts at the Maiden Theatre, via Woolloomooloo Gate.

Catalyst Features My Favourite

Amid Catalyst's sumptuous and scientific portrait of Sydney's Royal Botanic Gardens (with a brief mention of the Botanic Gardens Trust's seedbank at Mount Annan Botanic Garden), my favourite tree, and tree story, got some air time.

I've spoken and written about it a few times, but just in case you don't know the story of the 'Imperial Tree', read on...

There is a tree in the Royal Botanic Gardens with a royal name, and a royal origin.

The majestically named Chrysophyllum imperiale is from the rainforests of Brazil. Our largest specimen was planted by Prince Alfred, Duke of Edinburgh, and son of Queen Victoria in 1868.
The trip had its ups and downs. His Royal Highness had recently survived an assassination attempt at Clontarf, across the harbour. (Although a Florence Nightingale trained nurse Lucy Osburn soon brought the Prince back to full health, the incident sparked a period of racism in Australia with an anti-Irish Catholic movement lasting for many years.)

On the up, I think, as the first member of English royal family to visit Australia the Prince was welcomed with one of the earliest Sydney Harbour fireworks displays.

The tree itself is rare in its natural habitat and you are unlikely to see outside a few botanic gardens. In 1868 it was commonly found around Rio de Janeiro but that city’s spread has destroyed most of its natural habitat. In fact we sent some seed back to Rio to support their recovery program for this tree.

Also typically for that period, it was moved a few years later to a new spot – they liked doing that sort of thing and we still occasionally do it with younger trees.

The leaves are large, up to 40 cm long, slightly pleated and with toothed edges. The species name ‘imperiale’ is presumably a reference to its majestic leaves and overall bearing. The genus name means ‘golden leaf’, referring to the leaves of some species having a golden undersurface – Chrysophyllum imperiale doesn’t have golden leaves but the new growth has rusty hew…

We also the Star Apple, Chrysophyllum cainito, in the Gardens. It isn’t as impressive overall but it does have golden under-leaves and tasty fruits.

Apparently Chrysophyllum imperiale makes a nice pot plant when carefully pruned and the Friends of the Gardens sometimes have them available for sale. And if you want to see a close up of the magnificent leaves see my earlier posting.

The End of the World in 80 Gardens...

Monty Don from the BBC website.

Last night Monty Don finished his tour of the world ‘in 80 gardens’. He finished in Bali, after skimming through Thailand and Singapore in search of the perfect tropical garden.

Was the show successful? I watched every episode, but I’m a director and self-confessed ‘groupie’ of botanic gardens. Many people I know who aren’t directors of botanic gardens and have only a passing interest in gardens generally watched and enjoyed it.

Personally I found it a little short on plants, and stories about plants. Perhaps my own tour of the world would be ‘in 80 plants’? Still, Monty Don was clear about what he was doing and it wasn’t really about the plants themselves – he doesn’t particularly like ‘collections of plants’ and isn’t a great fan of botanic gardens.

We were lucky the Royal Botanic Gardens in Sydney got some attention. Apart from Kirstenbosch, a lovely alpine garden in Norway and us, there weren’t too many other botanic gardens featured (oh, and the wonderful Alice Springs Desert Park of course).

At the time (Show Two) I was disappointed that the focus was on flying foxes and the absence of Australian plants in our garden. Contrary to what Monty Don said, the flying foxes are quite transient on this site and there is no evidence they were on this site at the arrival of the First Fleet – the present camp has been here 20 years after a 70 year absence. And of course the Royal Botanic Gardens are packed with rainforest trees from eastern Australian and nearby islands.

Monty Don is enthusiastic, but a little too much for my taste. A rather large number of gardens were the best he’d ever seen. He also read a little too much into some of the gardens, rather than just enjoyed them. His fear of plant collections is a little too precious and his reaction to some of the tropical gardens as somehow not ‘authentic’ I think was condescending at best.

But as I said, I watched every episode. I enjoyed being taken for a tour through lots of different garden landscapes. Any travel show is fun, and one featuring gardens can’t be too bad. I particularly liked the show on Japan and China, with the views of the Green Mountain(s) unforgettable and clearly linked to the art from China.

Interesting that my most memorable part was the ‘natural landscape’, and a pine sticking out the side of a mountain. Perhaps there is room for a series on Around the World in 80 Plants, or Around the World in 80 Plant Landscapes. Not quite as catchy a title, but it would be fun – to make, and watch.

Asia-Pacific capacity building

Three perspectives on the Korean National Arboretum - the garden, making paper and part of their botanical museum

The Botanic Gardens Trust has made a commitment to work with neighbouring countries so they can create and maintain botanic gardens. Two years ago I visited Bogor to participate in a workshop for staff involved in designing eight new botanic gardens in Indonesia. China has apparently built nearly 100 in the last ten years.

Nearly all the new gardens have a strong conservation and local flora focus, and as part of the international botanic gardens community (if you are wondering, through a group called Botanic Gardens Conservation International, and meeting our obligations to the Global Strategy for Plant Conservation...) we want to make a difference to the conservation of plants worldwide.

There are lots of things we'd like to do, including setting up a Diploma in Botanic Gardens Management in the region, under the auspices of Botanic Gardens of Australia and New Zealand and Botanic Gardens Conservation International, and possibly run out of Singapore Botanic Gardens.

Korea is a country in the region with fewer needs than others but with a strong relationship with Australia already. Along with Indonesia, Korea was a strong supporter of APEC in its formative years. It is a country with a similar GDP to Australia (although its population is about double) and with a similar need to maintain connections outside the country (more so than China and USA). The links have always been strong in trade: mostly beef, gas and minerals to Korea, and cars and electronics to Australia. Both countries share an interest in education and communication. Interestingly Korea is a world leader in broadband holds regular summits with Australia attending on this topic.

Yesterday and today we hosted a visit by staff from the Korean National Arboretum. The delegation was headed by Dr Kim Yong-ha, Director-General of the Korean National Arboretum. Also with Dr Kim were Dr Lee Hae-Joo, Head of the Planning Section and Dr Kang Utchang, Senior Research Scientist. I'd met Dr Kang on my visit to Seoul last year for the meeting of the East Asian Botanic Gardens Network.

It's likely some of their staff will attend the diploma course in Singapore if we can get that up and running next year. They also have an interest in sending staff to Mount Annan Botanic Garden to learn more about caring for Australian plants, and us sending an expert to Korea to help them establish an Australian garden in a new Aboretum just out of Seoul.

So a wet tour of the Royal Botanic Gardens today and a fine one of Mount Annan Botanic Garden yesterday. No matter what the weather, the party seemed very impressed and we all enjoyed the visit.

Heritage trees matter too

One of the historic trees under threat from the 20-year old flying-fox camp in the Royal Botanic Gardens

As I announced in a media release a week ago, it is now too late to relocate the flying-foxes from Sydney’s historic Royal Botanic Gardens this year.

Our window of opportunity is May to July – after breeding and before the flying-foxes are carrying their young. And while the State Government has given approval, discussions are continuing with the Commonwealth Government. Even if a decision is made swiftly, it will take several weeks to set up the necessary research and monitoring before starting the noise disturbances.

We expect the flying-foxes to relocate relatively quickly to other Sydney camp sites, probably within two weeks. But we do need to allow for contingencies, such a new camp being established in an unsuitable area and further relocation being needed. Two months would be ideal.

So the flying-foxes stay another year. The camp arrived in the Royal Botanic Gardens 20 years ago, after a 70-year absence from this site. In those two decades we have lost 18 mature trees – about one a year. The camp peaks to about 22,000 animals in summer but drops to about 5000-10,000 in winter.

Good rainfall and excellent tree care have allowed the trust to nurse through many of the most severely affected trees, but as each year passes we stand to lose another of our majestic specimens.

While the approvals quite rightly take into account the welfare of the flying-foxes, they cannot take into account the damage caused to one of the world’s great botanical collections. The Commonwealth are doing their job, considering our application under the terms of the Environment Protection and Biodiversity Conservation Act 1999, but what about the health and long-term viability of our botanic gardens?

Let me make it clear, it’s not the botanic gardens or the flying-foxes. The Trust is confident it can safely relocate flying-foxes: the same techniques were used successfully to move a similar sized camp in Melbourne six years ago and to reduce numbers here in Sydney in the 1990s. If nothing is done, the botanic gardens will be trashed and the flying-foxes will need to move find a new place to camp, as they did twenty years ago when they returned to the botanic gardens.

Mass planting of fast-growing trees as roosting sites isn’t the answer. The tree collection is of immense scientific and heritage importance, and demonstrates the diversity of the world’s flora. We have started collecting seed from the wild to propagate and eventually restore the Palm Grove.

The 192-year old Royal Botanic Gardens is listed on the National Trust Register as a Landscape Conservation Area, and under the NSW Heritage Act as an item of Environmental Heritage. The Conservation Management Plan for the Royal Botanic Gardens identifies the whole site to be of exceptional national, state and local significance.

The Palm Grove, where most of the bats roost, is one of the older and more significant landscapes in the Gardens. The trees date back to the 1820s, and most of the palms to the 1860s. We’ve already lost a magnificent Kauri pine (Agathis moorei) collected by Charles Moore from New Caledonia in 1850. Of most concern at the moment is a Red Cedar collected from Parramatta in 1822 by the first head of the Botanic Gardens, Charles Fraser, and a Flindersia collected on the Oxley Expedition to the Brisbane and Logan Rivers in 1828.

There are 48 species of wild-collected palms, many of them rare in cultivation. Our Pritchardia maideniana were for many decades the only mature specimens of this species thought to exist in the world. Just a few years ago our collections were used to confirm the identity of a possibly natural population rediscovered in Hawaii.

Several new fungal species have been discovered and described from palms in the Palm Grove so these specimens become what we call ‘type localities’ – important scientific reference points. There are also many trees which are difficult to collect or rare in the wild, providing critical specimens for scientific study.

Under our current licences we’ve done all we can to deter the flying-foxes from the most sensitive trees. We’ve tried python poo, toilet crystals, shrimp paste, strobe lights, directed water sprays (when water was more freely available), plastic bags tied to branches, and even the colourful Inflatable Man. Over the next year we may have to net a few of the more important trees. None of these measures offer any long-term solution.

Carefully managed noise disturbance is proven and safe, and the welfare of the flying foxes will be paramount. Relocation is essential if we are to save Australia oldest botanic garden and its precious tree collection.

The Plant Hospital (Passion for Plants*)

Like us, plants are damaged, debilitated and killed by diseases. Sometimes they shrug off a minor infection, other times they only survive with some kind of surgery or chemical treatment.

With around 42,000 individual plants – excluding grasses in our lawns, but including more than 3,000 mature trees and about 9,000 different species and cultivars – the botanic garden needs a plant hospital. We call it the Plant Disease and Diagnostic Unit.

We now have a new ‘hospital’ building in our Central Depot, in the shadow of the Cahill Expressway. Like all hospitals, we have disease diagnosis and treatment areas, as well as research laboratories.

Most of the diagnoses are for soil-borne pathogens, particularly species that cause Phytophthora root rot. Treatment for Phytophthora cinnamomi, the usual culprit, includes adding more organic matter to the soil (to encourage other micro-organisms to out-compete it), improving drainage and under some conditions using the chemical phosphonate.

Generally you can only slow down its spread. It’s far better to use good garden hygiene to avoid Phytophthora getting into your garden in the first place.

Our research is mostly on fungi, but also includes Phytophthora (which is actually more closely related to the giant brown kelp in the sea than it is to a mushroom).

A lot of effort goes into detecting and documenting leaf diseases in the Proteaceae and Myrtaceae families, including well-known Australian plants such as the banksias and eucalypts.

Within eucalypts at least, there seems to be a close association between many of the fungal and eucalypt species, suggesting probably co-evolution of the host and its pathogen.

But with more eucalypts being planted overseas, new associations are formed between fungus and plant, sometimes with drastic consequences for the plant. Accelerated climate change may have the same result, as pathogen and plant respond differently to changes in temperature and rainfall.

We also have one of the world’s top research groups studying a deadly fungus called Fusarium oxysporum. This is actually a complex of different but related fungi that cause catastrophic crop losses in over 150 plant species, with huge economic consequences. It is also a major cause of palm deaths in Sydney.

The Botanic Gardens research team have discovered strains native to Australia, in soil as well as on local relatives of tomatoes, palms and cotton. This knowledge will help predict future adaptations of the fungus, as well as tracking the evolution of the pathogen to help manage its future spread.

But if you simply want to know what is wrong with you garden plant, and how to cure it, look up ‘Pests & diseases’ under the ‘Plant Info’ tab on the Gardens’ website or ring (02) 9231 8186. Note that this service does incur a charge.

*This posting will also appear on the ABC Sydney website (possibly under 'gardening'), and is the gist of my radio interview with Simon Marnie on Saturday Morning sometime between 9-10 am on 702AM.

It's fungi time

This picture, care of Dave Bidwell, shows a tree severely infected by Armillaria

Out walking in Lane Cove National Park yesterday I noticed lots of fungal fruiting bodies - toadstools of brown, red, green and blue hue. To remind us why there are so many around, it rained during the walk.

So now is the time to find out what fungal hyphae are lurking beneath your garden soil. The toadstools and mushrooms are of course the tip of the hyphal iceberg. Most plants needs fungi to survive so don't be too distressed to see the occasional fruiting body in your garden. However some of course are a big problem.

Just this week our head Arborist at the Royal Botanic Gardens, Dave Bidwell, sent out a reminder to us all to be on the look out for Armillaria Root Rot. As Dave said: "fruiting bodies of the fungus Armillaria luteobubalina are in evidence at present at or around the base of trees across the estate. Armillaria is a pathogen which can kill large trees, but sometimes acts as a saprophyte living off dead material. It is difficult to control...'

Dave included some photos with his email and I've included one of them here. It's a spectacular example on an Erythrina. The picture was taken last year and tree has since died and been removed.

Our Plant Pathology team is keen to map the distribution of the fungus in the Gardens so that we can limit its spread and work on local control measures.

As I told my walking companions yesterday, Armillaria (like all true fungi) is more closely related to us than it is to flowering plants. This doesn't really make any difference to the way we treat it but perhaps it's due a little more respect? Or maybe less if you are a botanist?

Flying Foxes to Stay Another Year

This is a copy of the Media Release we sent out today:

The Botanic Gardens Trust has decided to postpone its plans to relocate the flying-fox camp which is causing extensive damage to the historical trees at the Royal Botanic Gardens in Sydney.

Earlier this year the Trust received approval from the NSW Department of Environment and Climate Change for its plan to use noise disturbance to relocate Grey-headed Flying-foxes from the heritage-listed Royal Botanic Gardens to other camps in the Sydney area.

The noise disturbance technique has been employed successfully in the Royal Botanic Gardens Melbourne to move a similar-sized camp, and in the Sydney Gardens in the 1990s to reduce numbers.

Due to ongoing and incomplete discussions with the Commonwealth about the proposal, the Botanic Gardens Trust has resolved to suspend its proposed relocation for 2009.

Botanic Gardens Trust Executive Director, Dr Tim Entwisle, said that the decision to delay the relocation is disappointing but necessary. “We have always been clear about the need to disturb the camp only when it is safe for the flying-foxes.“

“Although we expect the relocation to occur relatively quickly, we need to allow extra time in case they settle in an unsuitable area. Our window of opportunity is May to July, after breeding and before the animals are carrying their young.”

Dr Entwisle says “Eighteen trees have been lost so far, but good rainfall and excellent tree care has meant that some of the most severely damaged trees have been nursed through another year.

“While relocation in 2009 would give us the best opportunity to save the remaining trees, I’m hopeful we can hold onto the most scientifically and culturally important specimens for another 12 months.”

The extra year gives the Trust time for further research and monitoring of camps in the Sydney area in preparation for the planned relocation.

Flying-foxes began settling in the Palm Grove in 1989 – nearly 70 years after they had been last reported in the Royal Botanic Gardens. Over the last two decades the camp has grown in size from a few hundred to a peak of 22,000 during summer months, resulting in extensive damage to a landscape of great historical, scientific and cultural value.

Dr Entwisle said, “The Trust is committed to safeguarding the precious heritage of the Royal Botanic Gardens, and to the relocation of the flying-foxes in accordance with state and federal requirements so there are no long-term adverse impacts on this vulnerable species.”

Smart Sydney Lights

OK, this isn't really about plants but we did have a light projector sitting in the Royal Botanic Gardens...

Tonight L and I explored the Smart Light Walk, part of Vivid Sydney. I downloaded a few images and videos from the Blue Tooth spot in Observatory Park, including an interview with Sydney's answer to Melbourne's Tiger Woods (I'm afraid you'll have the read the local papers to understand that).

And that's my next very slight botanical link, Brian Eno. Of course he put out two relevant albums - 'Before and After Science' in 1977 and 'Another Green World' in 1975.

But putting aside that other green world for a moment, enjoy these pictures of the Opera House, the Modern of Contemporary Art and Joe Snell's Songlines outside the Conservatorium.

Seeds at Sea

The floatable Coco de Mer (Lodoicea maldivica) among other fruits and seeds in the recent display by our Volunteer Guides for their 'Native Fruit and Nuts' talk and walk.

With long-distance dispersal becoming cool, and indeed necessary - how else do you get protea relatives from Australia to South Africa after the split of Gondwana (see my previous posting about the work of Peter Weston and colleagues) - it's time to look at oceanic journeys by plant seeds.

Let's turn our focus then from Seeds in Space to Seeds at Sea.

A neat PhD study on this topic is described in the latest issue of the Friends of Kings Park quarterly magazine 'For People & Plants'. It's the work of student Lydia Guja, guided by David Merritt and Kingsley Dixon of (Kings Park) Botanic Gardens and Parks Authority and Grant Wardell-Johnson of Curtin University of Technology.

The article starts with some historical context. That well-known botanist Charles Darwin was one of the first to test experimentally whether seeds will survive after floating in sea-water. In his garden at Downe - his laboratory for studies of pollination, climbing and carnivory in plants, among other things - Darwin discovered that some seed capsules and fruits could survive for up to 28 days, and some up to 137 days, as ocean currents washed them from one shore to another.

He figured that you could reasonably expect at least 10% of seeds in any country to travel 1,500 km. Of course most of these plants would occur naturally near the coast and would typically be salt-tolerant anyway.

With a simlar argument to the one used when we sent a few thousands seeds of Australian seeds into space, Lydia and her colleagues point out that no Western Australian coastal plants have ever been given the Darwin treatment.

And so the fruits of 13 WA species were floated in sea water for 70 days, and then the seed germinated. Ten survived the ordeal, with only one suffering a little from the experience. Event the three that germinate were thought to be inhibited by dormancy rather than salt and/or water.

The study will now move into testing the boyancy of different fruits, and into the physiology of surving high salt concentrations.

Does all this help us explain how protea relatives got to South Africa from Australia? Well not really, unless there is a salt tolerant ancestor somewhere in the Proteaceae family tree. Or perhaps a raft-building forebear?

Indoor Plants are Good for You

An indoor plant? From Sydney's 2007 Sculpture by the Sea.

On Gardening Australia on ABC TV tonight, Sophie Thompson mentioned recent studies showing that indoor plants are good for you. A few weeks back I spoke with Simon Marnie (Weekend Show, 702AM) about one of these studies, from an American hospital.

We also investigated the myth that indoor plants and flowers should be removed from rooms at night lest you die from lack of oxygen... This is the transcript of that chat.

"Plants are better than television and drugs. That’s a gross oversimplification of course, but a fascinating study of 90 people recovering from the surgical removal of their appendix found plants were pretty good. The study by Kansas State University was carefully planned and analysed, with post-surgery patients randomly assigned to hospital rooms with or without plants.

The patients with plants in their rooms felt better and took less pain medication. When asked what the best thing about their room was, nearly all of them said the plants. For the plant-deprived group, the television was the most liked aspect of their room.

Although not part of the study, it seemed that potted plants had better ‘healing properties’ than cut flowers. As patients recovered they would start to care for their potted friends, pruning and watering, and moving them into better light.

Other studies have demonstrated that indoor plants make the air healthier, and can increase humidity and reduce the quantity of harmful spores and bacteria.

But what about when the lights go out? Will you suffocate when the plant starts to consume more oxygen than it produces? During the day plants convert carbon dioxide and water to oxygen and carbohyd