Pterostylis obtusa, commonly known as the blunt-tongue greenhood, is a species of orchid endemic to New South Wales. It is distinguished from similar greenhood orchids by its thick, flat, platform-like sinus and blunt labellum which is only just visible above the sinus.
Pterostylis obtusa has a rosette of between three and six dark green, egg-shaped, crinkled leaves, each leaf NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide. A single shiny, bright green and white flower is borne on a flowering spike NaNsigfig=1NaNsigfig=1 high. There are between three and five stem leaves on the flowering spike. The flowers are NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide. The dorsal sepal curves forward in its upper half and has a thread-like tip about 4sigfig=1NaNsigfig=1 long. The edges of the petals are flared and the sinus is flat and platform-like with a rolled edge. The lateral sepals have thread-like tips NaNsigfig=1NaNsigfig=1 long. The labellum is NaNsigfig=2NaNsigfig=2 long, 3sigfig=1NaNsigfig=1 wide, green, blunt and is just visible above the sinus. Flowering occurs from February to June.[1] [2]
Pterostylis obtusa was first described in 1810 by Robert Brown and the description was published in Prodromus Florae Novae Hollandiae et Insulae Van Diemen.[3] [4] The specific epithet (obtusa) is a Latin word meaning "blunt" or "dull".[5]
The blunt-tongue greenhood grows among grass in moist places on the ranges and tablelands of New South Wales and on Lord Howe Island. Specimens from Tasmania are Pterostylis atrans.[6]