Pterostylis humilis

Pterostylis humilis is a species of orchid endemic to New Zealand. It has a rosette of leaves at the base of the plant and when flowering stem, leaves which usually obscure the dark green and white flower.

Greenhood
Scientific classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Orchidoideae
Tribe: Cranichideae
Genus: Pterostylis
Species:
P. humilis
Binomial name
Pterostylis humilis

Description

Pterostylis humilis is a terrestrial, perennial, deciduous, herb with an underground tuber and which often forms colonies. It has a loose rosette of leaves at the base and when flowering, between three and four more or less erect stem leaves, 40–90 mm (2–4 in) long and 15–25 mm (0.6–1 in) wide. The top-most leaves are higher than, and usually obscure the flowers. There is a single dark green flower with translucent white stripes and a reddish-brown tinge borne on a flowering stem 45–55 mm (1.8–2.2 in) tall or higher. The dorsal sepal and petals are fused, forming a hood or "galea" over the column. The dorsal sepal is more or less erect near its base then curves forward to the horizontal. The petals are slightly flared and slightly shorter than the dorsal sepal which has a short tip. There is a wide gap between the lateral sepals and the galea and the lateral sepals have thread-like tips which are erect, spread slightly apart from each other and are higher than the galea. The labellum is dark reddish-brown, curved and protrudes slightly above the sinus. Flowering occurs between November and January.[3][4]

Taxonomy and naming

Pterostylis humilis was first formally described in 1922 by Richard Rogers and the description was published in Transactions and Proceedings of the Royal Society of South Australia.[2][5] The specific epithet (humilis) is a Latin word meaning "low", "on the ground", "shallow" or "poor;".[6]

Distribution and habitat

This greenhood grows in montane forests of Nothofagus and in subalpine scrub. It occurs on the Volcanic Plateau and in the Egmont National Park on the North Island. On the South Island it occurs from near Nelson to near the Buller River.[3][4]

References
  1. Williams, E. (2017). Pterostylis humilis. The IUCN Red List of Threatened Species 2017: e.T22486134A22488070. https://doi.org/10.2305/IUCN.UK.2017-2.RLTS.T22486134A22488070.en. Downloaded on 12 November 2018.
  2. "Pterostylis humilis". World Checklist of Selected Plant Families (WCSP). Royal Botanic Gardens, Kew.
  3. de Lange, Peter James. "Pterostylis humilis". New Zealand Plant Conservation Network. Retrieved 29 June 2017.
  4. "Pterostylis humilis". New Zealand Native Orchid Group. Retrieved 28 June 2017.
  5. Rogers, Richard Sanders (1922). "Contributions to the orchidology of Australia and New Zealand". Transactions and Proceedings of the Royal Society of South Australia. 46: 151–152. Retrieved 11 March 2018.
  6. Brown, Roland Wilbur (1956). The Composition of Scientific Words. Washington, D.C.: Smithsonian Institution Press. p. 498.
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