Pterostylis erythroconcha explained

Pterostylis erythroconcha, commonly known as the red shell orchid, is a species of orchid endemic to South Australia. As with similar orchids, the flowering plants differ from those which are not flowering. The non-flowering plants have a rosette of leaves but the flowering plants have a single flower with leaves on the flowering spike. This greenhood has a white and green flower with reddish brown markings and a long, fleshy, curved labellum.

Description

Pterostylis erythroconcha is a terrestrial, perennial, deciduous, herb with an underground tuber and when not flowering, a rosette of between three and ten egg-shaped leaves. Each leaf is NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide. Flowering plants have a single flower NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide borne on a flowering stem NaNsigfig=1NaNsigfig=1 high. The flowers are translucent white with reddish-brown stripes and markings. The dorsal sepal and petals are fused, forming a hood or "galea" over the column. The dorsal sepal curves forward with sharp point or a thread-like tip NaNsigfig=1NaNsigfig=1 long. The lateral sepals are held closely against the galea, have an erect, thread-like tip NaNsigfig=2NaNsigfig=2 long and a broad, flat sinus with a small notch between their bases. The labellum is NaNsigfig=1NaNsigfig=1 long, about 4sigfig=1NaNsigfig=1 wide, thick, fleshy and reddish-brown protruding prominently above the sinus. Flowering occurs from April to August.[1] [2]

Taxonomy and naming

Pterostylis erythroconcha was first formally described in 1985 by Mark Clements and David Jones from a specimen collected near Corny Point. The description was published in the fourth edition of Flora of South Australia.[3] The specific epithet (erythroconcha) is derived from the Ancient Greek words erythros meaning "red"[4] and konche meaning "snail".

Distribution and habitat

The red shell orchid grows on calcareous sand and limestone, sometimes forming large colonies, usually near the coast, in mallee. It is found in the south-east of South Australia.

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. 291.
  2. Web site: Pterostylis erythroconcha. State Herbarium of South Australia: eflora SA. 27 June 2017.
  3. Web site: Pterostylis erythroconcha. APNI. 27 June 2017.
  4. Book: Brown. Roland Wilbur. The Composition of Scientific Words. 1956. Smithsonian Institution Press. Washington, D.C..