Pterostylis alpina, commonly known as the mountain greenhood,[2] is a species of orchidendemic to south-eastern Australia. It has a rosette of fleshy leaves at the base and usually only one white flower with green markings and back-swept lateralsepals.
Description
Pterostylis alpina is a terrestrial, perennial, deciduous, herb with an underground tuber and a rosette of three to five leaves surrounding the base of the flowering stem. Each leaf is egg-shaped to elliptic, 30–60 mm long and 15–30 mm wide. A single white flower with dark green marks and 25–30 mm long and 9–12 mm wide is borne on a spike 120–300 mm high. The dorsalsepal and petals are fused, forming a hood or "galea" over the column. The dorsal sepal curves forward with a pointed tip. There is a wide gap between the galea and the lateral sepals. The lateral sepals are swept back, have thread-like tips 13–18 mm long and a bulging sinus between them. The labellum is 12–14 mm long, about 3 mm wide, dark green to brown, blunt, and curved and protrudes above the sinus. Flowering occurs from August to October.[2][3][4][5]
The mountain greenhood is widespread in northern and eastern Victoria but is restricted to the Batlow region in New South Wales. It grows in high rainfall forests on the ranges, often on south-facing slopes.[2][3][4]
^ abcJones, David L. (2006). A complete guide to native orchids of Australia including the island territories. Frenchs Forest, N.S.W.: New Holland. p. 305. ISBN978-1877069123.
^ abJones, David L. "Pterostylis alpina". Royal Botanic Garden Sydney: plantnet. Retrieved 2 May 2017.
^ abJeanes, Jeff. "Pterostylis alpina". Royal Botanic Gardens Victoria: vicflora. Retrieved 2 May 2017.
^Mayfield, Enid (2010). Flora of the Otway plain & ranges (2nd ed.). Collingwood, Victoria: CSIRO Publishing. p. 146. ISBN9780643098046.