Pterostylis xerophila
Pterostylis xerophila, commonly known as the desert greenhood, is a plant in the orchid family Orchidaceae and is endemic to South Australia. Both flowering and non-flowering plants have a relatively large rosette of leaves. Flowering plants also have up to eight translucent white, green and reddish-brown flowers with an insect-like labellum. Description. "Pterostylis xerophila" is a terrestrial, perennial, deciduous, herb with an underground tuber and a rosette of between three and ten leaves. The leaves are long and wide. Flowering plants have a rosette at the base of the flowering stem but the leaves are  usually withered by flowering time. Up to eight white, green and reddish-brown flowers long and wide are borne on a flowering stem tall. The dorsal sepal and petals form a hood or "galea" over the column with the dorsal sepal having a narrow, upturned tip long. The lateral sepals turn downwards, are wider than the galea, dished, and suddenly taper to narrow tips long. The labellum is insect-like, about long, wide with a thin "body" and a thickened "head" end. Each side of the labellum has four to six forward-pointing bristles up to long. Flowering occurs from  September to November. Taxonomy and naming. "Pterostylis xerophila" was first formally described in 1986 by Mark Clements from a specimen grown in Adelaide from material collected in the Great Victoria Desert. The description was published in the fourth edition of the "Flora of South Australia". The specific epithet ("xerophila") is derived from the Ancient Greek words "ξερός (xeros)", meaning “dry” and "φίλος (phílos)", meaning "dear one" or "friend". Its common name as listed on the Commonwealth's SPRAT database is desert greenhood. Distribution and habitat. The desert greenhood usually grows in granite or quartzite rock outcrops in areas receiving an  average annual rainfall of less than , in and near the Great Victoria Desert. Conservation. "Pterostylis xerophila" is classified as "vulnerable" under the Australian Government "Environment Protection and Biodiversity Conservation Act 1999" and the South Australian Government "National Parks and Wildlife Act 1972". Little is known about the threats to this greenhood but include grazing by feral rabbits and goats, weed invasion, accidental destruction by vehicle movement and inappropriate fire regimes.