Prasophyllum robustum

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Robust leek orchid
Scientific classification Red Pencil Icon.png
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Orchidoideae
Tribe: Diurideae
Subtribe: Prasophyllinae
Genus: Prasophyllum
Species:
P. robustum
Binomial name
Prasophyllum robustum

Prasophyllum robustum, commonly known as the robust leek orchid, is a species of orchid endemic to Tasmania. It has a single tubular, green leaf and up to thirty greenish-brown flowers with a white labellum. It is only known from a single population of about fifty plants, its numbers having been reduced by land clearing.

Contents

Description

Prasophyllum robustum is a terrestrial, perennial, deciduous, herb with an underground tuber and a single tube-shaped leaf which is 300–850 mm (10–30 in) long and 5–6 mm (0.20–0.24 in) wide near its dark red to purple base. Between fifteen and thirty greenish-brown to brownish flowers are loosely arranged along a flowering spike which is 150–250 mm (6–10 in) long reaching to a height of 400–1,100 mm (20–40 in). The flowers are 15–20 mm (0.6–0.8 in) long and wide and as with other leek orchids, are inverted so that the labellum is above the column rather than below it. The dorsal sepal is lance-shaped to egg-shaped, about 9.5–11 mm (0.37–0.43 in) long, about 5 mm (0.2 in) wide and has about four dark brown striations. The lateral sepals are linear to lance-shaped, 10–12 mm (0.4–0.5 in) long, about 2.5 mm (0.1 in) wide and spread widely apart from each other. The petals are linear, 10–11 mm (0.39–0.43 in) long, about 2.5 mm (0.1 in) wide and whitish with a brown line along the centre. The labellum is white, egg-shaped to lance-shaped, 11–13 mm (0.4–0.5 in) long, about 6 mm (0.2 in) wide and turns sharply back on itself near its middle. The edges of the outer part of the labellum have crinkled or wavy edges and there is a raised, fleshy, green, channelled callus in its centre and extending to the bend. Flowering occurs in November and December. [2] [3] [4] [5]

Taxonomy and naming

The robust leek orchid was first formally described in 1940 by William Henry Nicholls who gave it the name Prasophyllum patens var. robustum from a specimen collected at Smithton. The description was published in The Victorian Naturalist . [6] [7] In 1998, Mark Clements and David Jones raised the variety to species status. [1] The specific epithet (robustum) is a Latin word meaning "hard and strong like oak". [8] [2]

Distribution and habitat

Prasophyllum robustum grows with shrubs and grasses in forest. It is only known from a single population of about fifty plants and the Smithton population appears to be extinct. Other populations have been lost due to land clearing for agriculture. [2] [4]

Conservation

The only remaining population of P. robustum is on private property with the current owners taking steps to preserve the species. Potential threats include land clearing, grazing by horses and inappropriate fire regimes. [4] [5]

Related Research Articles

Prasophyllum amoenum, commonly known as the dainty leek orchid or Snug leek orchid, is a species of orchid endemic to Tasmania. It has a single tubular, green leaf with a purplish base and between five and twelve light green, dark brown and white flowers. In 2007, the entire population was estimated to be about 600 plants.

Prasophyllum crebriflorum, commonly known as the crowded leek orchid, is a species of orchid endemic to Tasmania. It has a single tubular, dark green leaf with a purplish base and up to twenty five reddish-brown flowers. It is only known from four relatively small populations growing at high altitudes.

Prasophyllum erythrocommum, commonly known as the tan leek orchid, is a species of orchid endemic to Victoria. It has a single tubular green leaf and up to thirty small, greenish-brown to dark brown flowers. It is a very rare orchid, only known from a single small area north of Melbourne.

Prasophyllum favonium, commonly known as the western leek orchid, is a species of orchid endemic to Tasmania. It has a single tubular leaf with a reddish base and between five and fifteen brownish flowers with a dark purple labellum. In 2000, the entire population was estimated to be less than forty mature plants in a very small area.

Prasophyllum fosteri, commonly known as the Shelford leek orchid, is a species of orchid endemic to a small region of Victoria. It has a single tubular green leaf and up to twenty five green to reddish-brown flowers. It is a very rare orchid, only known from a single population on a roadside.

Prasophyllum incorrectum, commonly known as the golfer's leek orchid, is a species of orchid endemic to Tasmania. It has a single tubular, dark green leaf and up to twenty scented, yellowish-green and reddish-brown flowers. The largest population occurs on a golf course.

Prasophyllum limnetes, commonly known as the marsh leek orchid, is a species of orchid endemic to Tasmania. It has a single tubular, green leaf and up to thirty five greenish-white flowers with a pinkish labellum. It is only known from a population of fewer than twenty plants growing in a sanctuary near Port Sorell.

Prasophyllum milfordense is a species of orchid endemic to Tasmania. It has a single tubular, dark green leaf and up to thirty greenish-brown, white and purplish flowers. It is a very rare orchid, only found in a single location with a population of around 240 plants.

<i>Prasophyllum patens</i> Species of orchid

Prasophyllum patens, commonly known as the broad-lipped leek orchid or sandstone leek orchid, is a species of orchid endemic to the Sydney region of New South Wales. It has a single tubular green leaf and up to thirty green to greenish-brown, lemon-scented flowers with a white labellum.

Prasophyllum perangustum, commonly known as the Knocklofty leek orchid, is a species of orchid endemic to Tasmania. It has a single tubular, dark green leaf and up to fifteen greenish or light brown flowers with a white labellum. It is a very rare orchid with only six plants recorded in 1993.

Prasophyllum stellatum, commonly known as the Ben Lomond leek orchid, is a species of orchid endemic to Tasmania. It has a single tubular, dark green leaf and up to twenty greenish-brown to brownish flowers with a white labellum. It is only known from two disjunct populations, at Ben Lomond and near Deloraine.

<i>Prasophyllum subbisectum</i> Species of orchid

Prasophyllum subbisectum, commonly known as the Pomonal leek orchid, is a species of orchid endemic to Victoria. It has a single, thin tubular leaf and up to fifteen small, greenish-brown to brown flowers well-spaced along a thin flowering stem. It is only known from a small area around Stawell.

Prasophyllum truncatum, commonly known as the truncate leek orchid, is a species of orchid endemic to Tasmania. It has a single tubular, dark green leaf and up to twenty whitish flowers with purplish and greenish-brown markings. It is a late-flowering leek orchid and its flowering is stimulated by earlier fire.

<i>Prasophyllum tunbridgense</i> Species of orchid

Prasophyllum tunbridgense, commonly known as the Tunbridge leek orchid, is a species of orchid endemic to Tasmania. It has a single tubular, bright green leaf and up to twenty five relatively large, green to light greenish-brown flowers with white petals and a large white labellum.

Prasophyllum stygium, commonly known as the elfin leek orchid, is a species of orchid endemic to Victoria. It has a single tube-shaped leaf and up to twenty greenish-brown flowers with a white labellum. It is a recently described plant, previously included with P. fitzgeraldii, but distinguished from that species by its greenish-brown flowers with their white labellum and narrower brown callus. It is only known from a single population of about thirty plants.

Prasophyllum secutum, commonly known as the northern leek orchid, is a species of orchid endemic to Tasmania. It has a single tubular, green leaf and up to thirty scented, light brown flowers with a whitish labellum. It is only known from 18 populations and the total population is estimated to number fewer than 500 plants.

<i>Prasophyllum basalticum</i> Species of orchid

Prasophyllum basalticum is a species of orchid endemic to New South Wales. It has a single tubular, dark green leaf and up to fifteen scented, greenish-brown to brownish-red flowers with a white and green labellum. It grows in grassy woodland on the Northern Tablelands.

Prasophyllum graniticola is a species of orchid endemic to New South Wales. It has a single tubular, shiny dark green leaf and up to twenty five scented, greenish to brownish and white flowers. It is only known from two populations on the Northern Tablelands.

Prasophyllum holzingeri is a species of orchid endemic to New South Wales. It has a single tubular, shiny dark green leaf and up to fifteen unscented, greenish to brownish pink and white flowers. It is only known from a few populations in the Barrington Tops area.

Prasophyllum pilligaense is a species of orchid endemic to New South Wales. It has a single tubular, shiny dark green leaf and up to thirty scented greenish brown to brownish and white flowers. It is only known from a few populations in the Coonabarabran district.

References

  1. 1 2 "Prasophyllum robustum". APNI. Retrieved 22 December 2017.
  2. 1 2 3 Jones, David L. (1998). "Contributions to Tasmanian Orchidology". Australian Orchid Research. 3: 112–113.
  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. 201. ISBN   1877069124.
  4. 1 2 3 "Conservation advice Prasophyllum robustum" (PDF). Australian Government Department of the Environment. Retrieved 22 December 2017.
  5. 1 2 "Threatened species listing statement - Prasophyllum robustum" (PDF). Tasmanian Government Department of Primary Industries, Parks, Water and Environment. Retrieved 22 December 2017.
  6. ↑ "Prasophyllum patens var. robustum". APNI. Retrieved 22 December 2017.
  7. ↑ Nicholls, William H. (1940). "Some orchid notes". The Victorian Naturalist. 57. Retrieved 22 December 2017.
  8. ↑ Brown, Roland Wilbur (1956). The Composition of Scientific Words. Washington, D.C.: Smithsonian Institution Press. p. 766.
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