Pterostylis is a terrestrial deciduous genus in the Orchidaceae family of some 100 or so species of orchids found mainly in New Zealand, Australia, Papua New Guinea and New Caledonia. The common name of this tuberous orchid is Greenhood. A number of species have green flowers with the dorsal sepal forming a "hood" over the rest of the flower. The name Pterostylis is based on the Greek words meaning winged column (pteron - a wing, stylis - a column). In a number of species, the flower has a hinged lip that swings backwards when touched by an insect, forming a tube with the column and wings. The trapped insect is then forced to crawl out of the tube, removing the pollen in the process. Jones & Clements (2002, Australian Orchid Research volume 4) proposed segregating from this genus the following genera: Bunochilus, Crangonorchis, Diplodium, Eremorchis, Hymenochilus, Linguella, Oligochaetochilus, Petrorchis, Pharochilum, Plumatichilos, Ranorchis, Speculantha, Stamnorchis, Taurantha, Urochilus. This was not accepted. (2025).
Pterostylis curta R.Br., the blunt greenhood, is a quite common species from south east Australia and Tasmania, where it occurs in shrub and woodland areas. It is an easy subject for frost free potted culture in a well draining medium and has received the RHS Award of Garden Merit. Like most Pterostylis, it requires a dry summer rest. It flowers in mid spring. The pictures show plants grown by Martin Bohnet as received from European exchange 005, donated by Wim Boens.
Pterostylis dilatata A.S.George, syn. Linguella dilatata (A.S.George) D.L.Jones & M.A.Clem. is known as the robust snail orchid. It is endemic to the southwest of Western Australia. Flowering plants lack a rosette but have a single green and white flower on a flowering stem 5–15 cm (2–6 in) tall. The first two photos from iNaturalist were taken by ramcad1 and sarraj in Western Australia in July and June and shared under a CC BY-NC license. The last photo was photographed by Bob Rutemoeller in a forested area in southwestern Western Australia September 2007. Malcolm Thomas suspects it is this species.
Pterostylis melagramma D.L.Jones, syn. Bunochilus melagrammus (D.L.Jones) D.L.Jones & M.A.Clem. grows in moist areas in forests in shade in southeastern Australia (Tasmania, New South Wales, Victoria), often in sandy soil. It has narrow pointed leaves clasping the 40 cm stem and 1 to 7 slightly nodding hooded green flowers which are translucent with darker green markings. The lower sepals are deflexed and the tapered brownish lip has a dark central stripe and bristles. Height range: 15-80 cm. It flowers in the winter and spring. Photos taken by Bob Rutemoeller and Mary Sue Ittner in the Grampians, Victoria, October 2007.
Pterostylis nutans R.Br. produces a solitary nodding translucent flower to 2.5 cm long on a 25 cm stem. It has a basal rosette of wavy-edged stalked leaves. The hairy lip protrudes in the front of the flower. This orchid grows in moist sheltered areas in open forests and woodland in southeastern Queensland and southeastern Australia and on the north island of New Zealand. Photos taken October 2007 in the Grampians by Bob Rutemoeller and Mary Sue Ittner.
Pterostylis tasmanica D.L.Jones grows on heathland and heathy forest in well drained soils in New Zealand, New South Wales, Victoria, South Australia and Tasmania. It is similar to Pterostylis plumosa but has smaller flowers and long yellow hairs on the lip. The flower is about 2.5 cm long with the upper hooded part translucent with a netted pattern of dark green lines. This species was included in Plumatichilos with other bearded Greenhoods as Plumatichilos tasmanicus (D.L.Jones) Szlach., but in 2025 that is considered to be a synonym. Photos were taken by Bob Rutemoeller and Mary Sue Ittner October 2007 near Apollo Bay where it was growing in heathland.
Hybrids
Pterostylis 'RK Katano' (nutans x stricta, usually with the alba form of nutans) is a cross created by Heinrich Beyrle and was registered in 2011. It is a very vigorous hybrid multiplying rapidly - easily factor 3-5 per year. Starting growth in September it hibernates as a set of leaves under frost free conditions before sending up flowers by late spring. Like most Pterostylis it needs a dry summer rest. Pictures by Martin Bohnet show how the flower color varies from almost pure white to greenish in different years.
