Three of the new orchid species are endemic to the rugged Kimberley region of Western Australia.
The newly-identified species of orchids belong to two genera: Calochilus and Dipodium.
Calochilus kimberleyensis, Dipodium ammolithum and Dipodium basalticum are endemic to the Kimberley region, while Calochilus barbarossa is also found in Australia’s Northern Territory.
“The Kimberley having a strong seasonal climate, including a nine-month dry season, it was easy to think there was little habitat available for orchids,” said Dr. Russell Barrett, a researcher with the National Herbarium of New South Wales.
“Finding orchids in such a remote region can be a slow process, and this research has taken 30 years to reach publication.”
“Many people have assisted with the search over the decades, particularly Kimberley locals Robin and Butch Maher, both with a keen eye for potential habitats, and crucially, a helicopter at hand.”
“One of the key challenges in understanding species diversity has been the many connections between the Kimberley, South-east Asia, and other parts of northern Australia.”
The Kimberley region is largely unmanaged wilderness or free-range grazing land, subject to weed invasion, feral animals and high-frequency, broad-scale fires, each of which presents threats to orchid habitats and species.
Successful conservation of orchids in the region will ultimately rest on habitat conservation as most species are habitat specific.
In some cases, specific habitats could be beneficially fenced to protect orchids from damage by feral animals, particularly close to stock watering points.
Some habitats may require dedicated weed control to sustain orchid populations.
“A few species remain very poorly known in the Kimberley, with only a single location known for three of the ground orchids, Habenaria hymenophylla, Spiranthes sinensis, and Zeuxine oblonga,” Dr. Barrett said.
“Only a single site has been recorded for the tree orchid Dendrobium foelschei, but the population was subsequently killed by a hot fire that scorched the Melaleuca trees it grew in, so this species may no longer occur in the Kimberley.”
“Feral animals such as pigs could also destroy orchids and their habitats,” he added.
“Many orchid relationships remain poorly understood and new genetic data is likely to lead to additional name changes in coming years, and perhaps even additional species.”
“Orchids such as Habenaria eurystoma occur in very discreet areas in Western Australia, the Northern Territory and Queensland, separated by 1,000 km or more.”
“It remains to be determined how long these populations have been separated, and whether more than one species should be recognized. Genetic data is likely to be crucial in answering such questions.”
A paper describing the discovery was published in August 2022 in the journal Telopea.
Russell L. Barrett et al. 2022. A revision of Orchidaceae from the Kimberley region of Western Australia with new species of tropical Calochilus and Dipodium. Telopea 25; doi: 10.7751/telopea15711
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