Caladenia rigida

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Stiff spider orchid
Caladenia rigida 55402283.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Orchidoideae
Tribe: Diurideae
Genus: Caladenia
Species:
C. rigida
Binomial name
Caladenia rigida
Synonyms [1]

Caladenia rigida, commonly known as the stiff spider orchid, [2] or white spider-orchid [3] is a plant in the orchid family Orchidaceae and is endemic to South Australia. It is a ground orchid with a single hairy leaf and one or two white flowers with dark glandular tips on the sepals and fine reddish-brown lines along the sepals and petals.

Contents

Description

Caladenia rigida is a terrestrial, perennial, deciduous, herb with an underground tuber and a single hairy leaf 80–200 mm (3–8 in) long and 8–10 mm (0.3–0.4 in) wide. One or two white flowers with fine reddish-brown lines and 40–60 mm (1.6–2.4 in) across are borne on a spike 150–300 mm (6–10 in) tall. The sepals, but not the petals, have red, reddish-black or yellow-green glandular tips 8–12 mm (0.3–0.5 in) long. The dorsal sepal is erect near its base then gently curves forward and is 25–45 mm (1–2 in) long and about3 mm (0.1 in) wide. The lateral sepals are 40–50 mm (1.6–2.0 in) long and 4–7 mm (0.2–0.3 in) wide and spread stiffly apart. The petals are 25–37 mm (0.98–1.5 in) long, 3–5 mm (0.1–0.2 in) wide and arranged like the lateral sepals. The labellum is 14–16 mm (0.55–0.63 in) long and 9–11 mm (0.35–0.43 in) wide, and white. The sides of the labellum have many red, linear teeth up to 1.5 mm (0.06 in) long with white tips, and the tip of the labellum curves downwards. There are four or six rows of red calli with white tips along the labellum mid-line. Flowering occurs from August to October. [2] [4] [3] [5] [6]

Taxonomy and naming

Caladenia rigida was first formally described in 1930 by Richard Sanders Rogers and the description was published in Journal of the Adelaide Botanic Garden from a specimen collected near Golden Grove. [7] [6] The specific epithet (rigida) is a Latin word meaning "stiff", "rigid" or "inflexible". [8]

Distribution and habitat

The stiff spider orchid is only known from the Mount Lofty Ranges where it grows on the upper slopes of hills in open forest with an open shrub layer. [2] [3] [5]

Ecology

This orchid appears to attract pollinators both by sexual deception of thynnid wasps and by offering food rewards to other insect species. The species does not require fire to flower but some populations appear to benefit from fire, possibly due to the reduction of competition from other species, including grasses. [3] [9]

Conservation

Caladenia rigida is classified as "endangered" under the Australian Government Environment Protection and Biodiversity Conservation Act 1999 and the South Australian Government National Parks and Wildlife Act (1972). The main threats to the species include grazing, especially by kangaroos and weed invasion. [3] [5]

Related Research Articles

Caladenia argocalla, commonly known as white beauty spider orchid, is a plant in the orchid family Orchidaceae and is endemic to South Australia. It is a ground orchid which grows singly or in loose groups and has a single, hairy leaf and one or two white to greenish-white flowers on a wiry, hairy stalk. The total population is thought to be between 2,000 and 4,500 and it is classed as an "Endangered" species.

<i>Caladenia caudata</i> Species of orchid

Caladenia caudata, commonly known as tailed spider orchid, is a plant in the orchid family Orchidaceae and is endemic to Tasmania. It is a ground orchid with a single hairy leaf and up to four red, or yellow and red flowers with dark red to almost black tips.

<i>Caladenia cretacea</i> Species of orchid

Caladenia cretacea, commonly known as Stuart Mill spider orchid, is a plant in the orchid family Orchidaceae and is endemic to a small area in Victoria. It is a rare ground orchid with a single leaf and one or two white flowers on a hairy stalk.

Caladenia flaccida, commonly known as the flaccid spider orchid, is a plant in the orchid family Orchidaceae and is endemic to eastern Australia. It is a ground orchid with a single hairy leaf and up to three cream-coloured, pinkish or red flowers with long, thread-like, glandular tips on the sepals and petals.

<i>Caladenia fragrantissima</i> Species of orchid

Caladenia fragrantissima, commonly known as the scented spider orchid, is a plant in the orchid family Orchidaceae and is endemic to Victoria and South Australia. It is a ground orchid with a single hairy leaf and up to three creamy-white to yellowish-green flowers. It is possible that it is conspecific with Caladenia orientalis.

<i>Caladenia gladiolata</i> Species of orchid

Caladenia gladiolata, commonly known as small bayonet spider orchid, smelly socks or simply bayonet orchid is a plant in the orchid family Orchidaceae and is endemic to South Australia. It is a ground orchid with a single hairy leaf and one or two yellowish or brownish flowers with red stripes and unusual tips on the sepals and petals.

Caladenia helvina, commonly known as the summer spider orchid, is a plant in the orchid family Orchidaceae and is endemic to Tasmania. It is a ground orchid with a single hairy leaf and usually a single greenish-yellow to pale yellow flower with reddish teeth on the sides of the labellum and reddish calli along its mid-line.

Caladenia leptochila subsp. dentata, commonly known as the toothed spider orchid, narrow-lipped spider-orchid or narrow-lipped caladenia, is a plant in the orchid family Orchidaceae and is endemic to South Australia. It has a single leaf and one or two mostly reddish-brown flowers. It differs from subspecies leptochila in the colour of its flowers, toothed edges to its labellum, and its distribution.

<i>Caladenia longiclavata</i> Species of orchid

Caladenia longiclavata, commonly known as the clubbed spider orchid is a species of plant in the orchid family, Orchidaceae and is endemic to the south-west of Western Australia. It is a widespread and common orchid with a single, hairy leaf and one or two greenish-yellow, white and red flowers and which grows in the area between Perth and Albany.

Caladenia macroclavia, commonly known as the large-club spider orchid, or brown bayonets, is a plant in the orchid family Orchidaceae and is endemic to South Australia. It is a ground orchid with a single hairy leaf and a single green to yellowish-green flower with dark red central stripes. It is a rare species and in 2006 the total population was estimated to be between 35 and 80 mature plants.

Caladenia patersonii is a plant in the orchid family Orchidaceae and is native to Victoria and Tasmania. It is a ground orchid with a single hairy leaf and one or two creamy-white, yellowish or pink flowers.

Caladenia pumila, commonly known as the dwarf spider orchid is a plant in the orchid family Orchidaceae and is endemic to Victoria, Australia. It is a ground orchid with a single erect, hairy leaf and a single white flower with pale pink stripes. Its short flowering stem distinguishes it from other Victorian spider orchids. After 1933 it was presumed extinct until two plants were discovered in 2009.

Caladenia richardsiorum, commonly known as the little dip spider orchid, Richards' spider orchid or robe spider orchid, is a plant in the orchid family Orchidaceae and is endemic to South Australia. It is a ground orchid with a single erect, hairy leaf and usually only one yellowish-green flower. It is similar to the endangered Mellblom's spider orchid but has a much larger leaf and the petals lack glandular tips.

<i>Caladenia rosella</i> Species of orchid

Caladenia rosella, commonly known as the rosella spider orchid is a plant in the orchid family Orchidaceae and is endemic to south-eastern Australia. It is a ground orchid with a single hairy leaf and a single scented pink flower. Although it may have had a wider distribution in the past, the total number of plants in 2000 was estimated to be 120 in four populations in Victoria. There is a single record from New South Wales but the orchid is classified as "extinct" in that state.

Caladenia petrensis, commonly known as the rock spider orchid is a plant in the orchid family Orchidaceae and is endemic to the south-west of Western Australia. It has a single erect, hairy leaf and up to three pale yellow flowers with drooping lateral sepals and petals.

Caladenia stellata, commonly known as the starry spider orchid is a plant in the orchid family Orchidaceae and is endemic to south-eastern Australia. It is a ground orchid with a single, hairy leaf and usually only one greenish-cream flower with red markings.

<i>Caladenia valida</i> Species of orchid

Caladenia valida, commonly known as the robust spider orchid, is a plant in the orchid family Orchidaceae and is endemic to south-eastern continental Australia. It is a ground orchid with a single sparsely hairy leaf and up to three white to cream-coloured flowers which sometimes have red streaks. It is similar to Caladenia reticulata but is large and taller with more stiffly spreading lateral sepals and petals.

Caladenia woolcockiorum, commonly known as Woolcock's spider orchid, is a species of orchid endemic to South Australia. It has a single, long, erect, hairy leaf and one or two cream-coloured to greenish-yellow flowers recognised by their long, drooping lateral sepals and petals with their ends having dark glandular tips and by the red-tipped labellum.

Caladenia saxatilis is a plant in the orchid family Orchidaceae and is endemic to South Australia. It is a ground orchid with a single hairy leaf and one or two pale creamy-green flowers, sometimes with thin reddish lines. It occurs in the southern Flinders Ranges.

Caladenia intuta is a plant in the orchid family Orchidaceae and is endemic to two small areas on the Yorke Peninsula in South Australia. It is a ground orchid with a single hairy leaf and one or two white flowers which sometimes have faint reddish lines.

References

  1. 1 2 "Caladenia rigida". Australian Plants Census. Retrieved 4 October 2023.
  2. 1 2 3 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. 1 2 3 4 5 "Recovery plan for twelve threatened orchids in the Lofty block region of South Australia" (PDF). Australian Government Department of the Environment. Retrieved 17 March 2017.
  4. "Caladenia rigida". State Herbarium of South Australia: efloraSA. Retrieved 17 March 2017.
  5. 1 2 3 "White spider orchid Caladenia rigida" (PDF). Government of South Australia Department for Environment and Heritage. Retrieved 17 March 2017.
  6. 1 2 Rogers, Richard Sanders (1930). "Rogers, R.S. (1930), Contributions to the Orchidology of Papua and Australia". Journal of the Adelaide Botanic Garden. 54: 45–46. Retrieved 17 March 2017.
  7. "Caladenia rigida". APNI. Retrieved 17 March 2017.
  8. Brown, Roland Wilbur (1956). The Composition of Scientific Words. Washington, D.C.: Smithsonian Institution Press. p. 753.
  9. Faast, Renate Facelli; Farrington, Lachlan; Facelli, José M.; Austin, Andrew D. (2009). "Bees and white spiders: unravelling the pollination syndrome of Caladenia rigida (Orchidaceae)". Australian Journal of Botany. 57 (4): 315–325. doi:10.1071/bt08135.