Caladenia rhomboidiformis

Caladenia rhomboidiformis, commonly known as the diamond spider orchid, is a species of orchid endemic to the south-west of Western Australia. It has a single erect, hairy leaf and one or two green, yellow and red flowers. Until 1971 It was known as a variety of the green comb spider orchid Caladenia dilatata then, until 1989 as a variety of the clubbed spider orchid, Caladenia longiclavata.

labellum detail

Diamond spider orchid
Caladenia rhomboidiformis growing near Dunsborough
Scientific classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Orchidoideae
Tribe: Diurideae
Genus: Caladenia
Species:
C. rhomboidiformis
Binomial name
Caladenia rhomboidiformis
Synonyms

Description

Caladenia rhomboidiformis is a terrestrial, perennial, deciduous, herb with an underground tuber and a single erect, hairy leaf, 120–180 mm (5–7 in) long and about 2 mm (0.08 in) wide. One or two green, yellow and red flowers 40–70 mm (2–3 in) long, 40–60 mm (1.6–2.4 in) wide are borne on a stalk 200–450 mm (8–20 in) tall. The sepals have yellowish to brown, club-like glandular tips 2–10 mm (0.08–0.4 in) long. The dorsal sepal is erect, 30–40 mm (1–2 in) long and 2–4 mm (0.08–0.2 in) wide. The lateral sepals are 25–40 mm (1–2 in) long, 4–7 mm (0.2–0.3 in) wide, turn stiffly downwards and roughly parallel to each other. The petals are 20–30 mm (0.8–1 in) long, 3–4 mm (0.1–0.2 in) wide, spread widely and are also turned stiffly downwards. The labellum is 14–16 mm (0.55–0.63 in) long, 10–11 mm (0.39–0.43 in) wide, broadly diamond-shaped and white to yellow with a deep red tip. The sides of the labellum have greenish teeth up to 2 mm (0.08 in) long and the tip is curled under. There are four rows of deep red calli along the mid-line of the labellum. Flowering occurs from September to October.[2][3][4]

Taxonomy and naming

This orchid was first described in 1930 by Edith Coleman who gave it the name Caladenia dilatata var. rhomboidiformis and published the description in The Victorian Naturalist.[5][6] In 1971, Alex George recognised it as Caladenia longiclavata var. rhomboidiformis[7] and in 1989 Mark Clements and Stephen Hopper raised it to species status.[1] The specific epithet (rhomboidiformis) is derived from the Ancient Greek word ῥόμβος rhombos meaning "rhombus",[8]:263 the suffix oid meaning "likeness"[8]:483 and the Latin word forma meaning "shape" or "figure"[8]:346 referring to the diamond-shaped labellum of this orchid.[3]

Distribution and habitat

The diamond spider orchid is found between Busselton and Augusta in the Jarrah Forest and Warren biogeographic regions where it grows in a variety of habitats but often in jarrah forest, or Banksia or sheoak woodland.[2][3][4][9]

Conservation

Caladenia rhomboidiformis is classified as "not threatened" by the Western Australian Government Department of Parks and Wildlife.[9]

References
  1. "Caladenia rhomboidiformis". APNI. Retrieved 15 March 2017.
  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. 75. ISBN 1877069124.
  3. Brown, Andrew; Dundas, Pat; Dixon, Kingsley; Hopper, Stephen (2008). Orchids of Western Australia. Crawley, Western Australia: University of Western Australia Press. p. 114. ISBN 9780980296457.
  4. Hoffman, Noel; Brown, Andrew (2011). Orchids of South-West Australia (3rd ed.). Gooseberry Hill: Noel Hoffman. p. 155. ISBN 9780646562322.
  5. "Caladenia dilatata var. rhomboidiformis". APNI. Retrieved 15 March 2017.
  6. Coleman, Edith (1930). "A New Caladenia". The Victorian Naturalist. 46: 197. Retrieved 15 March 2017.
  7. "Caladenia longiclavata var. rhomboidiformis". APNI. Retrieved 15 March 2017.
  8. Brown, Roland Wilbur (1956). The Composition of Scientific Words. Washington, D.C.: Smithsonian Institution Press.
  9. "Caladenia rhomboidiformis". FloraBase. Western Australian Government Department of Parks and Wildlife.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.