Pterostylis jacksonii, commonly known as the southwest granite snail orchid, is a species of orchid endemic to the south-west of Western Australia. Both flowering and non-flowering plants have a rosette of leaves flat on the ground and flowering plants have a single green and white flower. It is only known from between Walpole and Albany.
| Southwest granite snail orchid | |
|---|---|
Scientific classification 
| |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Monocots |
| Order: | Asparagales |
| Family: | Orchidaceae |
| Subfamily: | Orchidoideae |
| Tribe: | Cranichideae |
| Genus: | Pterostylis |
| Species: | P. jacksonii
|
| Binomial name | |
| Pterostylis jacksonii | |
Description
editPterostylis jacksonii is a terrestrial, perennial, deciduous, herb with an underground tuber and a compact rosette of leaves 15–35 mm (0.6–1 in) in diameter. Flowering plants have a single green and white flower 9–11 mm (0.35–0.43 in) long and 5–8 mm (0.2–0.3 in) wide on a flowering stem 40–80 mm (2–3 in) high, sometimes with a light brown tinge. There is a single stem leaf 6–8 mm (0.2–0.3 in) long and 3–4 mm (0.1–0.2 in) wide on the flowering stem. The dorsal sepal and petals are fused, forming a slightly inflated hood or "galea" over the column. The lateral sepals are held close to the galea, almost closing the front of the flower and have erect, thread-like tips 14–17 mm (0.6–0.7 in) long. The labellum is broad but not visible from outside the flower. Flowering occurs in June and July.[2]
Taxonomy and naming
editPterostylis jacksonii was first formally described in 2014 by David Jones and Christopher French from a specimen collected in the Mount Frankland National Park and the description was published in Australian Orchid Review. The species had previously been known as Pterostylis sp. 'granite'.[3] The specific epithet (jacksonii) honours William Pownall Jackson, who discovered this species.[3]
Distribution and habitat
editThe southwest granite snail orchid grows with moss on granite outcrops between Walpole and Albany in the Warren biogeographic region.[2][4]
Conservation
editPterostylis echinulata is classified as "not threatened" by the Western Australian Government Department of Parks and Wildlife.[4]
References
edit- ^ "Pterostylis jacksonii". World Checklist of Selected Plant Families (WCSP). Royal Botanic Gardens, Kew.
- ^ a b Brown, Andrew; Dixon, Kingsley; French, Christopher; Brockman, Garry (2013). Field guide to the orchids of Western Australia : the definitive guide to the native orchids of Western Australia. Simon Nevill Publications. p. 360. ISBN 9780980348149.
- ^ a b "Pterostylis jacksonii". APNI. Retrieved 26 July 2017.
- ^ a b "Pterostylis jacksonii". FloraBase. Western Australian Government Department of Biodiversity, Conservation and Attractions.