Pterostylis tasmanica explained

Pterostylis tasmanica, commonly known as the small bearded greenhood, is a species of orchid in the family Orchidaceae which is native to south-eastern Australia and New Zealand. It has a single green flower with translucent "windows" and a long, thin labellum bordered with golden hairs. It is similar to P. plumosa but is shorter, with smaller leaves and flowers but a more densely feathery labellum.

Description

Pterostylis tasmanica is a terrestrial, perennial, deciduous, herb with an underground tuber . It has between eight and fourteen dark green leaves crowded around the base of the stem and extending upwards, the leaves NaNmm long and NaNmm wide. Flowering plants have a single green flower with translucent green panels, the flower NaNmm long and NaNmm wide arranged on a flowering stem NaNmm high. The dorsal sepal and petals are fused to form a hood or "galea" over the column, the dorsal sepal with a short point on its end. The lateral sepals are turned downwards, joined near their bases with tapering tips NaNsigfig=1NaNsigfig=1 long. The labellum NaNmm long, bearded with bright yellow hairs up to 3mm long and ending in a dark brown knob. The flowers appear from September to November.[1] [2] [3] [4] [5]

Taxonomy and naming

Pterostylis tasmanica was first described in 1994 by David Jones and the description was published in Muelleria from a specimen collected near Temma in the Arthur-Pieman Conservation Area.[6] The specific epithet (tasmanica) is refers to the distribution of this greenhood "being centred around Tasmania and the Tasmanian basin".

Distribution and habitat

The small bearded greenhood grows in coastal heath and scrub. It is widespread in Tasmania but also occurs on the south coast of New South Wales,[7] southern Victoria[8] the south-east of South Australia[9] and on both the North and South Islands of New Zealand.

Ecology

Pterostylis tasmanica is autogamous and the ovary is already swollen when the flowers open.

Notes and References

  1. Book: Jones. David L.. A complete guide to native orchids of Australia including the island territories. 2006. New Holland. Frenchs Forest, N.S.W.. 978-1877069123. 336.
  2. Jones. David L.. Contributions to Tasmanian Orchidology. Australian Orchid Research. 1998. 3. 154.
  3. Jones. David L.. New species of orchidaceae from south-eastern Australia. Muelleria. 1994. 8. 2. 190–191. 19 July 2017.
  4. Web site: de Lange. Peter James. Pterostylis tasmanica. New Zealand Plant Conservation Network. 20 July 2017.
  5. Web site: Pterostylis tasmanica. New Zealand Native Orchid Group. 20 July 2017.
  6. Web site: Pterostylis tasmanica. APNI. 19 July 2016.
  7. Web site: Pterostylis tasmanica. Royal Botanic Garden Sydney; plantnet. 19 July 2017.
  8. Web site: Jeanes. Jeff. Pterostylis tasmanica. Royal Botanic Garden Melbourne; vicflora. 19 July 2017.
  9. Web site: Census of South Australian Plants – Orchidaceae. State Herbarium of South Australia. 19 July 2017.