In a small green shed about an hour out of Melbourne, dozens of pot plants sit on a white plastic table, awaiting their turn to be measured.
A thick hairy leaf or two juts out from each pot, and occasionally, a thin stem carries a purple orchid flower with spindly petals pushing up towards the sky.
The cold morning dampens the orchid’s scent, but as the day heats up, the shed starts to smell a little musky as the flowers do their best to attract a pollinator.
With freezing fingers, volunteers unceremoniously tip the content of pots out onto the table and rummage through the dirt — hunting for the large root-like tubers of one of Australia’s rarest wild orchids.
“That’s next year’s tuber,” Alex McLachlan says as he pulls up the roots out of the dirt to show some of the other volunteers.
“You can tell that because it’s white and thick and flush.”
Dirt is searched through to check if there are any hidden orchids. (ABC Science: Jacinta Bowler)
He’s been here since very early this morning, but has been preparing the plants currently awaiting planting for much longer that.
As a research scientist at the Royal Botanical Gardens, he helped raise the rosella spider orchids from seed.
“There’s about a thousand in total,” he says, joking that there’s too many to give them names.
”But I am very happy to see them going back out into the wild where they belong.”
Mr McLachlan separates the tubers carefully and passes them off to another volunteer. They measure and record the plant’s length, number of flowers and leaves.
Over the next two days, volunteers will take trays of plants with their corresponding numbered tag carefully down the hill.
The rosella spider orchid (Caladenia rosella) is classified as critically endangered in Victoria, and is found nowhere else in the world.
A staggering 500 orchids are now ready to be planted into hard soil, almost doubling the number of these rare plants in the wild.
It’s not lost on Mr McLachlan that it takes dozens of volunteers and years of work to get to this point just with one species of plant.
“People don’t realise how much effort and how much money it is to get from a seed to this,” he says.
And with hundreds of orchids at risk of extinction in Australia alone, the race is on to save them.
The ‘crypticness’ of orchids
Go for a walk through the Australian bush and you might not notice orchids right under your feet.
While some grow on trees or rocks, the vast majority of Australia’s orchids hide under the soil.
Most of the time, they keep a low profile. Sometimes, it might be just a single grass-like leaf blade poking out of the ground.
“Orchids have this crypticness,” Megan Hirst, an research scientist at the Royal Botanic Gardens Victoria and the project lead explains.
“They need specialised pollinators. They have to have a relationship with the soil, the fungi.
“They’re really picky,” she laughs.
But if all the conditions are met, occasionally, a colourful and fragrant flower blooms.
Each orchid is measured and weighed before planting. (Supplied: Andie Dittman/Royal Botanic Gardens Victoria)
“When [orchids] come out and flower, it’s taken a lot to get there,” Dr Hirst says.
“It’s an awesome event.”
The variety is astounding. Many species produce colourful displays and scents to attract just one species of wasp, ant, fly, beetle or even bird.
The Canberra spider orchid (Caladenia actensis) produces flowers that look and smell like a female wasp.
The flowers of greenhood orchids (Pterostylis sp) hinge and close, trapping gnats to keep them on the plant for longer.
And the flying duck orchid (Caleana major), one of National Science Week’s contenders for Australia’s most amazing wildflower, has evolved an elaborate flower that looks like a duck in flight.
Many of Australia’s orchids exist nowhere else in the world, but more than 200 of them are at risk of extinction, according to the EPBC Act List of Threatened Flora.
While this sounds dire, there are groups around Australia working on solutions.
“The orchid conservation team at the Botanic Gardens [in Victoria] have something like 500 species in propagation,” Mr McLachlan says.
“There’s about eight threatened species, including non-orchid species, that are going back out into the wild this year.”
Catching packs of pollen
To get a glimpse of a rosella spider orchid in the wild is no easy feat.
Most of the year they are hidden in the soil, with a single leaf that emerges during winter and a single purple flower with long thin petals emerging in August and September.
Like many orchids, the rosella spider orchid has a symbiotic relationship with a only one species of pollinator.
The plant produces a musky, sweet smell which attracts the nectar seeking native bee Leioproctus platycephalus.
“It’s a pretty widespread bee, but this orchid is highly specialised to it,” says Linda Riquelme, an ecologist at La Trobe University.
“They have these pollinia, these little packs of pollen. It gets stuck either to the back of their head or on their thorax … and then they have to pull out the little pack.”
Rosella spider orchids used to be found across parts of Victoria and New South Wales, but their range has contracted to just four known locations around the north-east of Melbourne, with a combined footprint of the size of a suburb.
A rosella spider plant being put in the ground. (Supplied: Andie Dittman/Royal Botanic Gardens Victoria)
In 2000, just 120 wild plants remained across the small area. But since then, things have improved. Work has been done to protect the remaining ecosystem, and small numbers of plants have also been added to supplement the wild populations.
In 2023, scientists counted 655 mature plants.
While the increase is impressive, a few hundred plants will likely not protect the species from going extinct without future help.
“There’s just not that many around,” Dr Hirst says.
The new location — which has been kept secret for the plants’ protection — will be a fifth spot for the orchid to grow and thrive.
The team has already confirmed that Leioproctus platycephalus is in the area, which is vital to ensure the plants succeed in their new home.
“Hopefully there’s going to be more plants here than there are anywhere else,” she says.
How to grow an orchid
It’s a long and difficult process to get from powdery seeds to a flowering orchid ready to be planted in the ground.
“It is hard,” Mr McLachlan admits.
The orchid relies on a specific fungal species to grow.
The microscopic fungi — which for spider plants is a genus called Serendipita — fills the plant’s roots in a structure called a peloton.
The fungus is particularly important to the first part of the plant’s life.
“It won’t germinate without the fungi,” he says.
Alex McLachlan (left), Ben Cullin and Megan Hirst are working on protecting the rosella spider orchid. (Supplied: Andie Dittman/Royal Botanic Gardens)
The fungi is grown, and then added to the seed on petri dishes in sterile conditions. This is to ensure no other fungi or bacteria will infect the batch and kill the seedlings.
“The seedlings will form, and then they’re kept in our growth room back at Cranbourne,” he says.
“And they’ll stay in their little plates for about three months until they’re big enough to then go up into flasks.”
The flasks are their home for another few months until the leaves are about the size of matchsticks.
Rosella spider orchids take years of work before flowering. (Supplied: Andie Dittman/Royal Botanic Gardens Victoria)
Then, they’ll finally get added to soil in pots.
It will still be another year or two before they are ready to go into the ground, to make sure they’re as big and strong as they can be.
“If they’re extremely healthy, they can flower in their first year,” Mr McLachlan says.
“But mostly it’s second or third year plants which will be healthy.”
A garden of volunteers
It’s on a cold July morning, about three years after the seeds were propagated and much longer since the project started, that the team drive out of Melbourne to the planting location.
“It’s not the end point but, this is the fun bit,” Dr Hirst says.
“It’s taken years of work to get here.”
Volunteers from around Victoria gather on a small plot of land owned by Nature Conservancy Australia, with hundreds of rosella spider orchids in pots in tow.
Dozens of people from across Victoria came together for the two days of planting. (ABC Science: Jacinta Bowler)
Early in the day, things can be a little chaotic, Dr Hirst says.
“It starts off as massive anxiety attack until we work out the groups and work out what’s happening,” she laughs.
As the project lead, she seems to constantly be in multiple places at once: running up and down the hill to help people place cages over the delicate plants, giving others around her tips or a helping hand.
Orchids, she explains, have much more of a cult following than some other plants, and it’s visible in the number of people that have made their way out today — a mix of locals and those from much further abroad.
People from orchid societies hammer holes into hard ground. Ecology PhD students get on their hands and knees to carefully place each cultivated plant into its hole. There’s a mother and daughter who have driven hours to be here.
This flowering plant was part of the first batch of rosella spider orchids to be put in the ground. (Supplied: Andie Dittman/Royal Botanic Gardens Victoria)
Dr Hirst tears up when she describes how she feels about the people that have come out to be here.
“Everyone’s really trying their hardest … There’s obviously a shared experience here, everyone wants a good outcome,” she says.
“There’s got to be something behind that, and I think we’re tapping into it.”
But behind the joy and excitement for the days ahead, Dr Hirst knows better than most just how many other plants are in dire need of the same treatment as the rosella spider orchid.
“It’s trying to rally enough support,” she says.
“If you’re going to do it properly … there are things that need to be done. It’s not like we can just grab a couple of plants and whack them in.”
“It’s very doable, but we need funding to do that.”
