Pterostylis hians, commonly known as the opera house greenhood,[1] is a species of orchid endemic to New South Wales. Non-flowering plants have a rosette of leaves flat on the ground but flowering plants have a single shiny white and green flower. This greenhood is only known from a single location near Ulladulla.
Pterostylis hians is a terrestrial, perennial, deciduous, herb with an underground tuber and when not flowering, a rosette of dark green, more or less round leaves, each leaf NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide. Flowering plants have a single bright green and white flower NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide on a stem NaNsigfig=1NaNsigfig=1 tall. The dorsal sepal and petals are fused, forming a hood or "galea" over the column and the dorsal sepal has a short, sharply pointed tip. The lateral sepals are held closely against the galea, have erect thread-like tips NaNsigfig=1NaNsigfig=1 long and a protruding, platform-like sinus between their bases. The labellum is about 5sigfig=1NaNsigfig=1 long and 3sigfig=1NaNsigfig=1 wide, just visible above the sinus. Flowering occurs from March to May.[2]
Pterostylis hians was first formally described in 1997 by David Jones from a specimen collected near Manyana and the description was published in The Orchadian.[3] The specific epithet (hians) is a Latin word meaning "gaping" or "yawning".[4]
The opera house greenhood grows in shrubby forest in a small area near Ulladulla.