Pterostylis wapstrarum explained

Pterostylis wapstrarum, commonly known as the fleshy greenhood, is a plant in the orchid family Orchidaceae and is endemic to Tasmania. Both flowering and non-flowering plants have a rosette of leaves lying flat on the ground and flowering plants have up to fifteen crowded green flowers with darker green veins.

Description

Pterostylis wapstrarum, is a terrestrial, perennial, deciduous, herb with an underground tuber. It has a rosette of between four and seven, oblong to egg-shaped leaves, each leaf NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide, lying flat on the ground. Between five and fifteen green flowers with darker green veins are crowded together on a flowering spike NaNsigfig=1NaNsigfig=1 high with four to six stem leaves with their bases wrapped around it. The flowers are about 10sigfig=1NaNsigfig=1 long and 5sigfig=1NaNsigfig=1 wide with the dorsal sepal and petals joined to form a hood called the "galea" over the column. The dorsal sepal is gently curved but suddenly curves downward near the tip and is about the same length as the petals. The lateral sepals turn downwards and are about 8sigfig=1NaNsigfig=1 long, 11sigfig=1NaNsigfig=1 wide, fused together for most of their length and cup-shaped with their tips about 1sigfig=1NaNsigfig=1 apart. The labellum is about 3sigfig=1NaNsigfig=1 long, 2sigfig=1NaNsigfig=1 wide and whitish-green with a dark green, appendage. Flowering occurs from October to December.[1] [2]

Taxonomy and naming

Pterostylis wapstrarum was first formally described in 1998 by David Jones from a specimen collected near Pontville. The description was published in Australian Orchid Research, although as the orthographic variant Pterostylis wapstreorum.[3] The specific epithet (wapstrarum) honours Johannes ("Hans") and Annie Wapstra for their assistance to Jones.

Distribution and habitat

The fleshy greenhood grows in grassland and grassy forest near Pontville.

Conservation

Pterostylis wapstrarum is listed as "critically endangered" under the Australian Government Environment Protection and Biodiversity Conservation Act 1999 and as "endangered" under the Tasmanian Government Threatened Species Protection Act 1995.[4] The total population of this species is estimated to be fewer than 500 individual plants, none of which is known from a conservation reserve. It is threatened by habitat modification and land clearing, grazing by rabbits, inappropriate fire regimes, weeds, and destruction by the introduced red-legged earth-mite (Halotydeus destructor).[5]

Notes and References

  1. Jones. David L.. A taxonomic review of Pterostylis R.Br. in Tasmania. Australian Orchid Research. 1998. 3. 156–157.
  2. 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. 321.
  3. Web site: Pterostylis wapstrarum. APNI. 24 July 2017.
  4. Web site: Species Management Profile - Pterostylis wapstrarum (fleshy greenhood). Government of Tasmania Department of Primary Industries, Parks, Water and Environment. 24 July 2017.
  5. Web site: Pterostylis wapstrarum threatened species listing statement. Government of Tasmania Department of Primary Industries, Parks, Water and Environment. 24 July 2017.