Pterostylis stricta

Pterostylis stricta, commonly known as the northern greenhood, is a species of orchid endemic to Queensland. It has a rosette of leaves and when flowering a single translucent white flower with green lines, a reddish-brown tip and a curved, protruding labellum.

Northern greenhood
Scientific classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Orchidoideae
Tribe: Cranichideae
Genus: Pterostylis
Species:
P. stricta
Binomial name
Pterostylis stricta
Clemesha & B.Gray[1]

Description

Pterostylis stricta is a terrestrial, perennial, deciduous, herb with an underground tuber and a rosette of wrinkled leaves. Each leaf is 15–60 mm (0.6–2 in) long and 10–20 mm (0.4–0.8 in) wide. When flowering, there is a single white flower with green lines and a reddish-brown tip, 20–25 mm (0.8–1 in) long and 10–12 mm (0.4–0.5 in) wide which is borne on a flowering spike 100–300 mm (4–10 in) high. The dorsal sepal and petals are fused to form a hood or "galea" over the column, the dorsal sepal about the same length as the petals, all with a sharp point. There is a wide gap at each side of the flower between the petals and lateral sepals. The lateral sepals are erect with a tapering tip 12–15 mm (0.5–0.6 in) long and there is a broad, bulging sinus between them. The labellum is 14–16 mm (0.55–0.63 in) long, about 4 mm (0.2 in) wide, dark reddish-brown and curved, protruding above the sinus. Flowering occurs from March to July.[2][3]

Taxonomy and naming

Pterostylis stricta was first described in 1972 by Stephen Clemesha and Bruce Gray and the description was published in The Orchadian from a specimen collected near Ravenshoe.[4] The specific epithet (stricta) is a Latin word meaning "draw together", "hold in check" or "bind".[5]

Distribution and habitat

The northern greenhood grows with grasses and in sheltered gullies in forest between Mount Finnigan and Paluma at altitudes of between 800 and 1,250 m (2,600 and 4,100 ft).[2][3]

References
  1. "Pterostylis stricta". World Checklist of Selected Plant Families (WCSP). Royal Botanic Gardens, Kew.
  2. Jones, David L. (2006). A complete guide to native orchids of Australia including the island territories. Frenchs Forest, N.S.W.: New Holland. p. 304. ISBN 978-1877069123.
  3. "Pterostylis stricta". Trin keys: Australian Tropical Rainforest Orchids. Retrieved 18 July 2017.
  4. "Pterostylis stricta". APNI. Retrieved 18 July 2017.
  5. Brown, Roland Wilbur (1956). The Composition of Scientific Words. Washington, D.C.: Smithsonian Institution Press. p. 144.
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