Caladenia bicalliata subsp. bicalliata explained

Caladenia bicalliata subsp. bicalliata, commonly known as the limestone spider orchid or dwarf limestone spider orchid, is a plant in the orchid family Orchidaceae and is native to the south-west of Western Australia and coastal areas of South Australia. It has a single erect, hairy leaf and one or two cream-coloured flowers with reddish-brown tips.

Description

Caladenia bicalliata subsp. bicalliata is a terrestrial, perennial, deciduous, herb with an underground tuber and which occurs singly or in small clumps. It has a single erect, very hairy, linear to lance-shaped leaf, NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide. The inflorescence is a raceme, NaNsigfig=1NaNsigfig=1 high with one or two flowers, each flower NaNsigfig=1NaNsigfig=1 long and 4sigfig=1NaNsigfig=1 wide. The dorsal sepal is about 2sigfig=1NaNsigfig=1 long and abruptly narrows about one-third of its length from the base. The lateral sepals and petals are cream or greenish-cream, much shorter than those of the similar C. abbreviata and C. evanescens and have reddish-brown tips. The lateral sepals are less than 2sigfig=1NaNsigfig=1 long and thread-like for about half their length and the petals are about the same length and gradually taper to a thread-like tip. The labellum is egg-shaped, about 7sigfig=1NaNsigfig=1 long, 5sigfig=1NaNsigfig=1 wide and white with red stripes. The edge of the labellum is serrated and there are two rows of white-tipped calli along its centre. Flowering occurs from August to early October, however the flowers are often open for only one or two days and sometimes self-pollinate and do not open at all.[1] [2] [3] [4]

Taxonomy and naming

Caladenia bicalliata was first formally described by Richard Rogers in 1909[5] but in 2001 Stephen Hopper and Andrew Brown described two subspecies, including subspecies bicalliata and the description of the two subspecies was published in Nuytsia[6] The specific epithet (bicalliata) is a derived from the Latin bi- meaning "two", callus meaning "a callus" and -atus indicating possession, referring to the two pairs of rows of calli on the labellum.[7]

Distribution and habitat

Limestone spider orchid occurs in a narrow coastal strip, growing in calcareous soil between Kalbarri and Esperance in Western Australia and along the south-east coast but sometimes up to 100sigfig=1NaNsigfig=1 inland in South Australia.[8]

Conservation

Caladenia bicalliata subsp. bicalliata is classified as "not threatened" by the Western Australian Government Department of Parks and Wildlife.

Notes and References

  1. Book: Brown. Andrew. Dixon. Kingsley. French. Christopher. Brockman. Garry. Field guide to the orchids of Western Australia : the definitive guide to the native orchids of Western Australia. 2013. Simon Nevill Publications. 9780980348149. 52.
  2. Book: Hoffman. Noel. Brown. Andrew. Orchids of South-West Australia.. 2011. Noel Hoffman. Gooseberry Hill. 9780646562322. 26. 3rd.
  3. Web site: Caladenia bicalliata. State Herbarium of South Australia: efloraSA. 12 October 2016.
  4. Web site: Caladenia bicalliata subsp. bicalliata. Government of South Australia Department for Environment and Heritage. 12 October 2016.
  5. Web site: Caladenia bicalliata. APNI. 12 October 2016.
  6. Web site: Caladenia bicalliata subsp. bicalliata. APNI. 12 October 2016.
  7. Book: Francis Aubie Sharr . Francis Aubie Sharr . Western Australian Plant Names and their Meanings . 2019 . Four Gables Press . Kardinya, Western Australia . 9780958034180 . 146.
  8. Book: Paczkowska. Grazyna. Chapman. Alex R.. The Western Australian flora : a descriptive catalogue. 2000. Wildflower Society of Western Australia. Perth. 0646402439. 76.