Display boxes in the Australian Botanic Garden Mount Annan HerbariumCredit: Rhett Wyman
Within minutes of slipping into the back rooms of the Australian Botanic Garden at Mount Annan, on Sydney’s south-western fringe, it is clear the research facility is more akin to a zoo than a greenhouse.
Botanical body parts resembling reticulated possum tails and giant scorpion stingers pickle in jars. Liquid nitrogen billows in one room. Green tendrils wriggle out of seeds in refrigerated corners. The scent of drying eucalypt oil flavours the air and, at the covert swipe of a keycard, a full-length mirror in a hallway whirrs aside to reveal a secret entrance.
“This is the most biodiverse spot in the country, probably,” says Professor Brett Summerell, chief scientist of the gardens. We’ve stepped through to a room filled with racks of drying flannel flowers and all manner of foliage curing between TV guides from last month’s Herald. Its walls are a bank-vault style concrete cube mounted with a 500-kilogram fireproof window. The spot Summerell is referring to is beyond a second heavy freezer door: the inner sanctum of the PlantBank’s seed vault. He lugs it open.
Professor Brett Summerell opening the cryo storage dewar at the Botanic Garden PlantBank.Credit: Rhett Wyman
That reveals a room the size of a shipping container set at minus 18 degrees, about the temperature of a kitchen freezer. There are rows of metallic silver bags filled with seeds; a growing collection of Australian plants, enough to reboot entire ecosystems.
The PlantBank contains material from about 20 per cent of Australia’s seed-bearing flora. There is one alien species, though, in a conspicuous pile of yellow envelopes: the pollen of a corpse flower.
The blooming of Sumatran superstar “Putricia” at Sydney’s Royal Botanic Garden last week became perhaps the biggest moment for botanic science in the city’s history. Millions watched Putricia’s fronds inch apart online and 27,000 people queued – many for more than three hours – to snatch a two-minute glimpse and a malodorous whiff.
Putricia’s fame was boosted by the garden staff’s commitment to theme within her retro glasshouse; think the camp-goth aesthetic of Little Shop of Horrors, a Lynchian vibe summoned by a mist machine and dreamy classical music, and a stench worthy of Nosferatu’s undergarments.
Putricia in full bloom last Thursday night.Credit: Janie Barrett
During her fleeting flowering, horticulturists scraped away Putricia’s pollen with a dessert spoon. John Siemon, director of horticulture at Botanic Gardens of Sydney, whisked the packages to Mount Annan in the dead of night. Now the precious granules are subject to the same study many hundreds of plants have undergone: can the pollen withstand minus 20 degree temperatures? For how long? What about cryopreservation, at minus 180? For a critically rare Sumatran plant with a wild population of 400, such questions are crucial.
Next door, seed bank manager Dr Nathan Emery is bent over a microscope, peering down at perfectly round globules dyed cobalt blue. The pollen has been treated with a concoction of chemicals and sugars replicating the sticky “stigma” (female pollen-seeking) organ of a corpse flower which, hopefully, will trigger the pollen to germinate if it’s viable.
Putricia the corpse flower’s pollen germinating with plant ovary-seeking tubes through a microscope.Credit: Rhett Wyman
“It’s early days at the moment, but we are starting to see some pollen tubes coming through,” Emery says. These pale tendrils normally grow down into the flower to fertilise a plant’s ovaries, triggering the production of fruit and seeds. “It’s looking quite promising.”
While recent days have been all about Putricia, for years scientists at this facility have studied how to best store Australian plant species and test how they’ll react as the weather turns more extreme.
A resident liquid nitrogen-filled dewar – a cryogenic storage flask – that can store 30,000 specimens in suspended animation serves as the ultimate long-term safeguard. But not all species can withstand the snap-freeze. Once frozen, the cells of many rainforest plants explode.
Those species are kept alive in the tissue culture lab, where plants are painstakingly propagated over and over in sphagnum moss and solutions of agar, sometimes spiked black with toxin-draining charcoal.
Rows of rainforest plants, some functionally extinct, in the tissue culture lab.Credit: Rhett Wyman
There are hundreds of palm- to fingernail-sized plants, ranging from underground Rhizanthella orchids to lilly pillies and native guava.
“Most of the species here are affected by the exotic introduced disease myrtle rust, which came into the country in 2010,” Summerell says.
About 16 different species are on the brink of extinction.
“[Myrtle rust] has a huge, huge potential host range; all of the Myrtaceae family, which include eucalypts, paperbarks, lilly pillies – 20 per cent of Australian flora, essentially,” Summerell says.
“My research focuses on plant diseases, so this one’s very close to my heart.”
The ruthless fungal disease savages growing leaves, stops fruiting and can rapidly kill a plant. In the face of such a foe, preserving as many diverse individuals as possible of these life-support cuttings is crucial. Genetic diversity is the ammo of evolutionary resilience. One of these tiny sprouts may contain the DNA key to myrtle rust resistance. Failing that, immunity may could one day be crafted with gene-editing tool CRISPR.
Rows of Lenwebbia from the myrtle family, decimated in the wild by myrtle rust.Credit: Rhett Wyman
“But how much should we play God? It’s a really complex question,” Summerell says. “At the moment we’re just looking for natural resistance, using true and tried techniques that are less controversial and less expensive.”
We head outside – past a murky pool of floating marshwort sprouting yellow, fuzzy flowers, and a grevillea that thrusts its blooms onto the ground so they look like spiky red millipedes – and enter an enormous shaded nursery.
Here there are rows of potted Lenwebbia, a subtropical shrub with hairy leaves rescued from the cloud forests of northern NSW and southern Queensland. Some were grown from cuttings gathered by plant collectors who rappelled down cliff faces to reach every specimen they could.
“This is it. This is the world’s population right here in front of you,” says Siemon. Staff regularly douse the shrubs in fungicide; spores of myrtle rust are so pervasive that even here, the nation’s botanical sanctum, the fungus would alight on their leaves and commence its attack.
“It’s crazy,” Summerell says. “If this happened to a mammal, can you imagine the hoo-ha?”
It’s an enormous operation, but keeping species from the brink is only a fraction of the services offered here. While some scientists look forward, others are looking back.
We meet identification expert Andrew Orme within the garden’s herbarium. He’s squinting at the pages of a 130-year-old Bible.
“It’s my great uncle’s Bible,” says Norm Small, a member of the public who brought in the enormous tome. “When my grandson was going through it, we found these plants.”
Norman Small bought his great uncle Charles Edward Small’s Bible to the herbarium at Australian Botanic Garden Mount Annan to help identify plant material found within.Credit: Rhett Wyman
There are slender brown daisy seeds dried onto Samuel 2:12-16. In other pages, Orme has uncovered fragments of pansies and peas. The herbarium holds a library of 1 million species – recently digitised – that help identify plant material, from the biblical to weeds that sicken cows, and cannabis brought in by cops.
In the air-locked concrete vaults of the herbarium – strictly quarantined against bugs such as cigarette beetles, which could devour the lot – rows of red boxes hold preserved lichen clinging to bark and red seaweed dried on a page like steamrolled fairy floss. Summerell produces a banksia flower gathered in April 1770 by botanists Joseph Banks and Daniel Solander.
This specimen, along with the rest of their collection, was soaked by seawater when their ship, HMS Endeavour, struck the Great Barrier Reef later that year; the banksia we are looking at was laid out on the ship’s sails to dry near what is now called Cooktown in Queensland.
Banksia serrata specimen collected by Joseph Banks in Botany Bay, 1770. Credit: Rhett Wyman
The banksia made it to Banks’ private collection in England, then to the Natural History Museum London, and was eventually repatriated to Australia in the 1900s to join 833 of his specimens. Its seafaring journey exemplifies the international trading web that makes a botanic garden.
“Last year we distributed to 35 institutions around the globe, mostly in the UK, England, Ireland, Europe, in the United States and around Australia,” Siemon says, standing in a nursery of young Wollemi pines. The prehistoric trees grow in black studded pots with holes for their roots to grow out – they’re reminiscent of dinosaur hides.
The pink fronds of Kallymenia rosea algae reach from a storage unit.Credit: Rhett Wyman
Like the velvet myrtle, every single Wollemi in the wild is represented in this nursery. Each is tagged with the exact location, tree and stem it was propagated from. Thirty years after their extraordinary discovery in a secret grove, the pines now aren’t uncommon in backyard gardens. But here, there’s enough to lose yourself within the fronds. You feel their mythology bearing down on you, as though the shade they cast carries weight.
Scientists still gather seed from wild Wollemis – which has historically involved a collector dangling from a steel cable slung from a helicopter – in the never-ending quest for more genetic gunpowder. Now, as in zoos with critically endangered animals, we have a “meta population” spread across the globe. Another six baby plants were sent around the globe recently as yet another back-up.
“They’re surprisingly adaptable,” says Summerell. “They grow beautifully in the south of England.”
John Siemon, director of horticulture, among the Wollemis. Every wild pine is represented in this nursery population.Credit: Rhett Wyman
The importance of the global lifeline has never been sharper. Several species of the root-rotting pathogen Phytophthora (the scientists’ second nemesis, after myrtle rust) have infected the wild Wollemis. Their roots can be drenched in fungicide, but that takes hundreds of litres delivered by air. Injecting the treatment creates an unwanted wound.
Summerell’s team are working on a non-invasive treatment that can permeate bark.
But that’s just disease risk; Black Summer could have razed them all.
“The environment is changing so quickly, and more and more exotic impacts are happening,” Summerell says. “The need to do all of this work across all 25,000 species of Australian species of plants is becoming more and more urgent.”
Botanic Gardens of Sydney’s new chief executive, Simon Duffy, spent 27 years at Taronga Zoo. The style of conservation work is practically identical between the institutions, he says.
Simon Duffy joined Botanic Gardens of Sydney as CEO last year from Taronga Zoo.Credit: Wolter Peeters
Duffy was overseas when Putricia’s skirt began to part, but he raced back and managed to catch the end of the show last Friday. He says a spate of recent corpse flower bloomings – in Geelong (named Casper), Cooktown (Big Betty) New York (Smelliot), London (Unnamed) and Boston (Dame Judi Stench) – is partly a consequence of enormous public interest in the plants, which has led to a direct boon in the conservation efforts of corpse flowers and the work of botanic gardens generally.
“She sparked an interest in the community, which demonstrates how much people love and adore plants in nature,” Duffy says. “Plants are the basis of all life. They give us clean water, clean air. They give us medicines. They give us food.
“My takeaway is that, despite our current situation where we’re facing some very wicked problems, people still have hope, and they still want to be inspired.
“And she was a great inspiration story.”
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