Pterostylis bicolor, commonly known as the black-tip greenhood, is a plant in the orchid family Orchidaceae and is endemic to south-eastern Australia. It has a rosette of leaves and when flowering, three to ten well-spaced, bright green flowers with a blunt, greenish-black appendage on the labellum. It is similar to the swan orchid, Pterostylis cycnocephala but that species has a beak-like appendage and crowded flowers.
Description
Pterostylis bicolor, is a terrestrial, perennial, deciduous, herb with an underground tuber. It has a rosette of between five and twelve dark green leaves, each leaf 10–35 mm (0.4–1 in) long and 3–15 mm (0.1–0.6 in) wide. When flowering there are between three and ten well-spaced, bright shiny green flowers 8–11 mm (0.3–0.4 in) long and 4–5 mm (0.2–0.2 in) wide on a flowering spike 80–300 mm (3–10 in) tall. Six to eleven stem leaves are wrapped around the flowering spike. The dorsalsepal and petals form a hood or "galea" over the column. The lateral sepals turn downwards, 6–7 mm (0.2–0.3 in) long and 7–8 mm (0.28–0.31 in) wide, dished and joined for most of their length. The labellum is egg-shaped, 3 mm (0.1 in) long and 2 mm (0.08 in) wide, with a greenish-black, blunt, ridged, forward pointing appendage. Flowering occurs from August to November.[2][3][4]
The black-tip greenhood is widespread in New South Wales and found in scattered populations in Victoria. It grows in grassy woodland and forest.[2][3][4]
^ abJones, David L. (2006). A complete guide to native orchids of Australia including the island territories. Frenchs Forest, N.S.W.: New Holland. p. 320. ISBN978-1877069123.
^ abJones, David L. "Pterostylis bicolor". Royal Botanic Garden Sydney: plantnet. Retrieved 27 May 2017.
^ abJeanes, Jeff. "Pterostylis bicolor". Royal Botanic Gardens Victoria: vicflora. Retrieved 27 May 2017.
^Brown, Roland Wilbur (1956). The Composition of Scientific Words. Washington, D.C.: Smithsonian Institution Press. p. 28.