Pterostylis hians, commonly known as the opera house greenhood, 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. Description 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 long and wide. Flowering plants have a single bright green and white flower long and wide on a stem 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 long and a protruding, platform-like sinus between their bases. The labellum is about long and wide, just visible above the sinus. Flowering occurs from March to May. Taxonomy and naming 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. The specific epithet (hians) is a Latin word meaning "gaping" or "yawning". Distribution and habitat The opera house greenhood grows in shrubby forest in a small area near Ulladulla. References hians Endemic orchids of Australia Orchids of New South Wales Plants described in 1997