Praecoxanthus

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Leafless orchid
Praecoxanthus aphyllus (7226183884).jpg
P. aphyllus growing near Pinjarra
Scientific classification Red Pencil Icon.png
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Orchidoideae
Tribe: Diurideae
Subtribe: Caladeniinae
Genus: Praecoxanthus
Hopper & A.P.Br.
Species:
P. aphyllus
Binomial name
Praecoxanthus aphyllus
(Benth.) Hopper & A.P.Br.
Synonyms [1]
  • Caladenia aphyllaBenth.

Praecoxanthus aphyllus, commonly known as leafless orchid, is the only species of the flowering plant genus Praecoxanthus in the orchid family, Orchidaceae and is endemic to the south-west of Western Australia. Plants in flower lack a true leaf, although those plants that are not flowering do possess a green leaf. This species is one of the first orchids to flower each year and its creamy white, fragrant flower easily distinguishes it from other species.

Contents

Description

Praecoxanthus aphyllus is a terrestrial, perennial, deciduous, sympodial herb with a few inconspicuous, fine roots and a tuber partly surrounded by a fibrous sheath. The tuber produces a replacement "dropper" which becomes the daughter tuber in the following year. Non-flowering plants produce a single, stalkless, egg-shaped leaf which is 20–40 mm (0.8–2 in) long, 8–20 mm (0.3–0.8 in) wide and glabrous with prominent white veins. The leaf of flowering plants is reduced to a tiny bract at the base of the stem. [2] [3] [4]

There is a single resupinate flower on the end of a wiry, glabrous stem 20–40 cm (8–20 in) high. The flower is 2–4 cm (0.8–2 in) wide and long. The three sepals and two petals are spreading, creamy-white, free and similar in size and shape to each other. As is usual in orchids, one petal is highly modified as the central labellum. The labellum has three lobes and is purple, green and yellow with two irregular rows of stalked, club-like calli. The sexual parts of the flower are fused to the column, which has wing-like structures on its sides and are widest at the base. Flowering occurs from March to May and the fruit that follows is a non-fleshy, hairy, dehiscent capsule containing a large number of seeds. [2] [3] [4]

Labelled image Praecoxanthus labelled.pdf
Labelled image

Taxonomy and naming

Leafless orchid was first formally described in 1837 by George Bentham who gave it the name Caladenia aphylla and published the description in Flora Australiensis . [5] [6] In 2000, Stephen Hopper and Andrew Brown described the genus Praecoxanthus and included this species. [7]

The genus name "Praecoxanthus" is derived from the Latin word praecox meaning "premature" or "precocious" [8] :629 and the Ancient Greek anthos meaning "flower". [8] :54 The specific epithet "aphyllus" is derived from the Ancient Greek prefix "a-" meaning "without" [8] :62 and phyllon meaning "leaf". [8] :605

Ecology

Leafless orchid flowers are highly fragrant and attract native bees. The yellow calli on a purple labellum resemble pollen-bearing stamens but the flower is nectarless, [4] attracting the insects to an absent reward. [9]

Distribution and habitat

This orchid usually grows in sandy soils in woodland but near Esperance tends to grow in low heath with sub-soil moisture. Unlike some orchids, they do not usually grow in colonies and individuals are well-spaced. [2] [10] It occurs between Pinjarra and Albany and in a coastal strip east to Esperance [2] in the Avon Wheatbelt, Esperance Plains, Jarrah Forest, Mallee, Swan Coastal Plain and Warren biogeographic regions. [11] [12]

Conservation

Praecoxanthus aphyllus is classified as "Not Threatened" by the Western Australian Government Department of Parks and Wildlife. [11]

Related Research Articles

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

Caladenia marginata, commonly known as the white fairy orchid, is a species of orchid endemic to the south-west of Western Australia. It has a single pale green, hairy leaf and up to four creamy-white flowers and often grows in dense colonies, flowering profusely after summer fires.

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

Caladenia saccharata, commonly known as sugar orchid, is a species of flowering plant in the orchid family, Orchidaceae and is endemic to the south-west of Western Australia. It has a single leaf and a single flower with three white sepals and two similar petals.

Caladenia abbreviata, commonly known as the coastal 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, creamy-yellow flowers on a flowering stem up to 35 cm (10 in) high. Although the flowers have long, thread-like petals and sepals, they are shorter and darker than those of other spider orchids. It is a rare, relatively recently discovered species although often found near human activities.

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

Caladenia ambusta, commonly known as the Boranup 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, linear leaf and a single creamy-coloured flower on a stem 27–35 cm (11–14 in) high. It is only known from a relatively small area south-west of Margaret River growing in deep sand in shrubland and woodland and only flowering profusely after fire.

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

Caladenia arrecta, commonly known as the reaching 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 red, yellow and green flowers on a flowering stem up to 35 cm (10 in) high. It is distinguished from the similar C. longiclavata and C. magniclavata by its upswept petals and distinctive calli. Although not common, it is widespread in south-eastern coastal areas.

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.

Caladenia bicalliata 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. There are two subspecies differing in the size and colour of the flowers.

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

Caladenia christineae, commonly known as Christine's 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 four small, white to cream-coloured flowers. It is distinguished from similar spider orchids by its small, odourless flowers with their stiffly held sepals and petals.

Caladenia corynephora, commonly known as the club-lipped 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 one or two greenish-yellow and red flowers which have a labellum with a club-like tip. It is the only Western Australian caladenia with a clubbed labellum.

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

Caladenia cruscula, commonly known as the reclining spider orchid is a species of orchid endemic to a small area in the south-west of Western Australia. It has a single hairy leaf and a single cream-coloured flower with a long red fringe on the sides of its labellum.

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

Caladenia exstans, commonly known as the pointing spider orchid, is a species of orchid endemic to a small area in the south-west of Western Australia. It has a single, hairy leaf and one or two green, yellow and red flowers with a labellum which does not curl downwards but "points" forward.

Caladenia graminifolia, commonly known as the grass-leafed spider orchid is a species of orchid endemic to the south-west of Western Australia. It has a single glabrous leaf and one or two short-lived, greenish-yellow and red flowers which have a narrow labellum with long teeth on its sides.

<i>Caladenia hirta <span style="font-style:normal;">subsp.</span> hirta</i> Subspecies of orchid

Caladenia hirta subsp. hirta, commonly known as the sugar candy orchid or candy orchid, is a plant in the orchid family Orchidaceae and is endemic to the south-west of Western Australia. It has a single leaf and up to three creamy-white or pink flowers with brownish tips and a brown back.

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

Caladenia horistes, commonly known as the cream spider orchid is a species of orchid endemic to the south-west of Western Australia. It has a single, hairy leaf and one or two, creamy-yellow flowers which have a red-striped labellum and long, dark, thread-like tips on the sepals and petals.

<i>Caladenia longicauda <span style="font-style:normal;">subsp.</span> rigidula</i> Subspecies of orchid

Caladenia longicauda subsp. rigidula, commonly known as the rigid white spider orchid or island white spider orchid, is a plant in the orchid family Orchidaceae and is endemic to the south-west of Western Australia. It has a single hairy leaf and up to three large, mainly white flowers with relatively short lateral sepals and petals. It is similar to the reclining white spider orchid but that species has smaller, cream-coloured flowers.

Caladenia sigmoidea, commonly known as the sigmoid spider orchid, is a species of orchid endemic to the south-west of Western Australia. It has a single erect, hairy leaf and usually only one red and cream-coloured flowers with an unusual S-shaped labellum.

Caladenia ultima, commonly known as the late spider orchid, is a species of orchid endemic to the south-west of Western Australia. It has a single erect, hairy leaf and up to three creamy-yellow flowers with a red-striped labellum. It is one of the last spiders orchids to flower each year.

Caladenia validinervia, commonly known as the Lake Muir spider orchid, is a species of orchid endemic to the south-west of Western Australia. It has a single erect, hairy leaf and up to three greenish to creamy white flowers with red stripes on the sepals and petals. The flowers have relatively narrow sepals and petals and a relatively small labellum. It is a rare orchid only known from an area between Rocky Gully and Collie.

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

Caladenia vulgata, commonly known as the common spider orchid, is a species of orchid endemic to the south-west of Western Australia. It is a relatively common and widespread orchid with a single erect, hairy leaf and up to three creamy-white flowers. There is some variation in the species, both in flower colour and growth habit.

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

Caladenia gemmata, commonly known as the blue china orchid, is a plant in the orchid family Orchidaceae and is endemic to the south-west of Western Australia. It has a small, oval leaf and up to three intense blue to mauve flowers. It is the most common and widespread of the West Australian china orchids, sometimes appearing in large numbers after summer fires.

References

  1. "Praecoxanthus". World Checklist of Selected Plant Families (WCSP). Royal Botanic Gardens, Kew . Retrieved 25 June 2016.
  2. 1 2 3 4 Hoffman, Noel; Brown, Andrew (2011). Orchids of South-West Australia (3rd ed.). Gooseberry Hill: Noel Hoffman. pp. 210–212. ISBN   9780646562322.
  3. 1 2 "Praecoxanthus". FloraBase . Western Australian Government Department of Parks and Wildlife.
  4. 1 2 3 Pridgeon (ed.), Alec M.; Cribb (ed.), Phillip J.; Chase (ed.), Mark W.; Rasmussen (ed.), Finn (2001). Genera Orchidacearum, Volume 2, Orchidoideae (part 1). Oxford, England: Oxford University Press. pp. 113–115. ISBN   0198507100.CS1 maint: extra text: authors list (link)
  5. "Caladenia aphylla". APNI. Retrieved 25 June 2016.
  6. Bentham, George (1837). Flora Australiensis. 6. London: Lovell Reeve and Co. p. 387. Retrieved 25 June 2016.
  7. "Praecoxanthus aphyllus". APNI. Retrieved 25 June 2016.
  8. 1 2 3 4 Brown, Roland Wilbur (1956). The Composition of Scientific Words. Washington, D.C.: Smithsonian Institution Press.
  9. Groom, Philip K. Groom; Lamont, Byron (2014). Plant Life of Southwestern Australia Adaptations for Survival. Berlin: De Gruyter. p. 138. ISBN   9783110370164.
  10. Archer, William (21 July 2008). "Praecoxanthus aphyllus". Esperance Wildflowers. Retrieved 25 June 2016.
  11. 1 2 "Praecoxanthus aphyllus". FloraBase . Western Australian Government Department of Parks and Wildlife.
  12. Paczkowska, Grazyna; Chapman, Alex R. (2000). The Western Australian flora : a descriptive catalogue. Perth: Wildflower Society of Western Australia. p. 87. ISBN   0646402439.