Pterostylis parca commonly known as the Lithgow leafy greenhood is a plant in the orchid family Orchidaceae and is endemic to New South Wales. Non-flowering plants have a rosette of leaves on a short stalk. Flowering plants lack a rosette but have up to eight translucent pale green flowers on a flowering stem with three to six stem leaves.
Pterostylis parca, is a terrestrial, perennial, deciduous, herb with an underground tuber. Non-flowering plants have a rosette of between three and four narrow egg-shaped leaves, each leaf NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide on a stalk NaNsigfig=1NaNsigfig=1 high. Flowering plants have up to eight translucent pale green flowers on a flowering spike NaNsigfig=1NaNsigfig=1 high. The flowering spike has between five and seven stem leaves which are NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide. The flowers are NaNsigfig=1NaNsigfig=1 long, NaNsigfig=1NaNsigfig=1 wide. The dorsal sepal and petals are joined to form a hood over the column with the dorsal sepal having a brown tip. The lateral sepals turn downwards and are NaNsigfig=1NaNsigfig=1 long, NaNsigfig=1NaNsigfig=1 wide and joined to each other for more than half their length. The labellum is about 4sigfig=1NaNsigfig=1 long, 2sigfig=1NaNsigfig=1 wide, reddish-brown and hairy with a dark stripe along its mid-line. Flowering occurs from August to October.[1] [2]
The Lithgow leafy greenhood was first formally described in 2006 by David Jones who gave it the name Bunochilus parcus and published the description in Australian Orchid Research from a specimen collected near Lithgow.[3] In 2010, Gary Backhouse changed the name to Pterostylis parca.[4] The specific epithet (parca) is a Latin word meaning "frugal", "scanty", "thrifty" or "penurious",[5] referring to the small labellum of this species.
Pterostylis parca grows in moist places in forest in the Lithgow and Bathurst areas.[6]