Life on the Line: The Rarest Orchids We’re Fighting to Save

Though every orchid species that the Orchid Conservation Program works with is endangered, some are so rare that they're down to single-digit populations.

Threats to these beautiful species range from habitat degradation to introduced flora and fauna species and trampling by livestock. While protecting these exceptionally rare orchids from these threats is no simple feat, Royal Botanic Garden's Orchid Conservation Program team are battling each day to make sure they don't disappear. Take a look at some of our most critically endangered orchids, teetering on the brink of extinction, that we're fighting to save. 

Blue-tongue Greenhood (Pterostylis orephila)

Down to just one tiny wild population, the Blue-tongue Greenhood (Pterostylis orephila), which gets its common name from the distinctive blue-green labellum ‘tongue’ that protrudes from its flowers, is critically endangered. Found in a few areas close to streams in Victoria’s subalpine forests and shrublands, these environments were ravaged by bushfires last summer, decimating wild populations and leaving little hope of survival for the species.

In collaboration with La Trobe University, our team have been out in the field this spring undertaking vital fire recovery work, in order to propagate Pterostylis orephila in the laboratory this Summer. When ready, the propagated specimens will be used to regenerate native habitats, and seeds will be collected and stored at Cranbourne with the Orchid Conservation Program seed collection, and also in New South Wales at the Australian National Botanic Gardens the Victorian Conservation Seedbank, ensuring that any future environmental emergencies won’t come at the cost of our precious biodiversity. 

Dwarf Spider Orchid (Caladenia pumila

One of the most threatened orchids on the planet, there are just two Dwarf Spider Orchid plants (Caladenia pumila) remaining in the wild, growing in grassy woodland near Bannockburn. Since Caladenia pumila was first described in the early 1920s, population number declined dramatically, with just two specimens remaining in the wild a decade later. Presumed extinct, the two wild plants we know of now were discovered by chance in 2009. The Orchid Conservation Team has been busy saving this species from extinction, hand-pollinating plants, collecting seed and growing 100 Caladenia pumila specimens in the laboratory and nursery. 

Coloured Spider Orchid (Caladenia colorata)

Protecting the Coloured Spider-orchid (Caladenia colorata) is a remarkable example of the multifaceted work that the Orchid Conservation Program achieves, as it required the team to unravel the mysteries of its pollination, propagation and habitat for introduction back into the wild.

While like all our native orchids, Caladenia colorata requires a specific mycorrhizal fungi, habitat and climate, it's also known for being the first case of food deception in Australian orchids where just one species of thynnid is involved. Royal Botanic Gardens Victorias' Dr Noushka Reiter and colleagues from UWA and ANU discovered that Caladenia colorata relies on a particular native wasp for pollination, emitting small amounts of sucrose from the labellum which the wasp feeds on.

This complex system of moving parts takes years to understand and mimic in the lab and field, but the hard work has paid off. The Orchid Conservation Program, working with wonderful private landholders, has been able to introduce over 800 Caladenia colorata plants in several locations. These are now recruiting, with over 600 seedlings having germinated from seed set on these sites. We now have self-sustaining populations with consistent natural flowering, pollination and recruitment!

Your support is critical to ensuring the Orchid Conservation Program can protect and regenerate these species so that they continue to play their vital role in native habitats. Donate today and help save these precious species from extinction


Published on