Pterostylis subtilis, commonly known as the thin mountain greenhood, is a species of orchid endemic to New South Wales. It has a rosette of leaves and when flowering a single translucent white flower with dark green lines, a narrow, deeply notched sinus between the lateral sepals and a curved, protruding labellum.

Thin mountain greenhood
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Orchidoideae
Tribe: Cranichideae
Genus: Pterostylis
Species:
P. subtilis
Binomial name
Pterostylis subtilis

Description edit

Pterostylis subtilis is a terrestrial, perennial, deciduous, herb with an underground tuber and a rosette of fleshy leaves lying flat on the ground. Each leaf is 30–50 mm (1–2 in) long and 15–25 mm (0.6–1 in) wide. When flowering, there is a single white flower with dark green lines, 35–45 mm (1–2 in) long and 15–20 mm (0.6–0.8 in) wide which is borne on a flowering spike 120–250 mm (5–10 in) high. The dorsal sepal and petals are fused to form a hood or "galea" over the column, the dorsal sepal slightly longer than the petals and all sharply pointed. There is a narrow gap at each side of the flower between the petals and lateral sepals. The lateral sepals are erect with a tapering tip 15–20 mm (0.6–0.8 in) long and there is a deep, narrow sinus between them. The labellum is 16–20 mm (0.6–0.8 in) long, about 3 mm (0.1 in) wide, blunt and curved, protruding above the sinus. Flowering occurs in December and January.[2]

Taxonomy and naming edit

Pterostylis subtilis was first described in 2006 by David Jones and the description was published in Australian Orchid Research from a specimen collected in the Barrington Tops National Park.[3] The specific epithet (subtilis) is a Latin word meaning "thin", "fine", "slender" or "acute ".[4]

Distribution and habitat edit

The thin mountain greenhood grows with grasses on sheltered forest slopes in the Barrington Tops National Park.[2][5]

References edit

  1. ^ "Pterostylis subtilis". World Checklist of Selected Plant Families (WCSP). Royal Botanic Gardens, Kew.
  2. ^ a b Jones, David L. (2006). A complete guide to native orchids of Australia including the island territories. Frenchs Forest, N.S.W.: New Holland. p. 306. ISBN 978-1877069123.
  3. ^ "Pterostylis subtilis". APNI. Retrieved 18 July 2017.
  4. ^ Brown, Roland Wilbur (1956). The Composition of Scientific Words. Washington, D.C.: Smithsonian Institution Press. p. 768.
  5. ^ "Pterostylis subtilis". Royal Botanic Garden Sydney; plantnet. Retrieved 18 July 2017.