Prasophyllum subbisectum

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Pomonal leek orchid
Prasophyllum subbisectum.jpg
Prasophyllum subbisectum growing near Ararat
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. subbisectum
Binomial name
Prasophyllum subbisectum

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.

Contents

Description

Prasophyllum subbisectum is a terrestrial, perennial, deciduous, herb with an underground tuber and a single tube-shaped leaf 100–150 mm (4–6 in) long and 2–4 mm (0.08–0.2 in) wide. Between seven and fifteen flowers are well-spaced along a flowering stem 60–100 mm (2–4 in) long which reaches to a height of 150–300 mm (6–10 in). The flowers are greenish-brown to brown and as with others in the genus, are inverted so that the labellum is above the column rather than below it. The dorsal sepal is lance-shaped to egg-shaped, 5–6 mm (0.20–0.24 in) long, about 3 mm (0.1 in) wide and curves downward. The lateral sepals are 7–8 mm (0.28–0.31 in) long, about 1 mm (0.04 in) wide and curve backwards. The petals are 5–6 mm (0.20–0.24 in) long, about 1 mm (0.04 in) wide and pointed. The labellum is greenish or pinkish, egg-shaped, about 4 mm (0.2 in) long and 5 mm (0.2 in) wide and turns sharply upwards near its middle. There is a shiny green or brown, deeply channelled callus along the centre of the labellum, extending almost to its tip. Flowering occurs in October and November. [2] [3] [4]

Taxonomy and naming

Prasophyllum subbisectum was first formally described in 1936 by William Henry Nicholls and the description was published in The Victorian Naturalist from a specimen collected near Pomonal. [1] [5] The specific epithet (subbisectum) is derived from the Latin word sectus meaning "cut", [6] :247 with the prefixes sub- meaning "somewhat" [6] :826 and bi- meaning "two" or "double". [6] :823

Distribution and habitat

The Pomonal leek orchid mostly grows in heathy woodland near Stawell. [2] [4]

Conservation

In 2010, P. subbisectum was recorded in four populations with a total of about 130 plants. It is listed as "Endangered" under the Commonwealth Government Environment Protection and Biodiversity Conservation Act 1999 (EPBC) Act and the Victorian Flora and Fauna Guarantee Act 1988 . The main threats to its survival are grazing by rabbits and kangaroos, habitat disturbance and inappropriate fire regimes. [4] [3]

Related Research Articles

Prasophyllum pyriforme, commonly known as the graceful leek orchid is a species of orchid species endemic to eastern Australia. It has a single tubular leaf and up to fifty greenish flowers with a pink or white labellum. As with others in the genus, the labellum is above the column rather than below it.

Prasophyllum australe, commonly known as the southern leek orchid or austral leek orchid, is a species of orchid and is endemic to south-eastern Australia. It has a single tubular, green leaf and up to fifty scented, greenish-brown flowers with red stripes.

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

Prasophyllum petilum, commonly known as the Tarengo leek orchid, is a species of orchid endemic to eastern Australia. It has a single tubular, green leaf and up to eighteen pinkish mauve to greenish flowers, well-spaced along a slender flowering stem. It is a small orchid, difficult to locate, generally growing in taller grasses.

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

Prasophyllum canaliculatum, commonly known as the channelled leek orchid or summer leek orchid, is a species of orchid endemic to a small area of southern New South Wales. It has a single tubular, bright green leaf and up to twenty five scented, greenish-red or brownish flowers on a flowering stem. It grows in woodland at altitudes around 1,000 m (3,000 ft) where only about two hundred plants survive.

Prasophyllum candidum, commonly known as the Kiandra leek orchid, is a species of orchid endemic to eastern Australia. It has a single tubular, yellowish-green leaf and up to forty scented, bright white to greenish flowers. It grows in subalpine areas at altitudes above 1,000 m (3,000 ft) in New South Wales and Victoria although in the latter state it is considered to be a form of P. odoratum.

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

Prasophyllum caudiculum, commonly known as the Guyra leek orchid, is a species of orchid endemic to a small area of northern New South Wales. It has a single tubular, bright green leaf and up to thirty five greenish to reddish-brown flowers crowded along an erect flowering stem. It grows in grassy places near Guyra.

Prasophyllum concinnum, commonly known as the trim leek orchid, is a species of orchid endemic to Tasmania. It has a single tubular leaf and green or yellowish-green flowers with brown markings. It was not seen after 1947, presumed to have gone extinct and listed as "rare" under the Tasmanian Government Threatened Species Protection Act 1995 but was rediscovered in 1992. Flowering of this orchid is dramatically stimulated by summer fires and the species is now known to be widespread in the state and has been removed from the Act.

Prasophyllum brevilabre, commonly known as the Gorae leek orchid, is a species of orchid endemic to south-western Victoria. It has a single tubular, green leaf and up to forty greenish-brown flowers with reddish markings. It is a very rare orchid, now only known from two small, scattered populations. It was first recorded from Gorae West near Portland but is no longer found there.

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 gracillimum, commonly known as the slender leek orchid, is a species of orchid endemic to a small region of Western Australia. It has a single tubular green leaf, and green, brown and white flowers loosely arranged along the flowering stem. This species has not been seen for more than fifty years and is considered by some botanists to be a form of P. fimbria.

Prasophyllum incompositum is a species of orchid endemic to Queensland. It has a single tubular, dark green leaf and up to thirty scented, greenish-brown and white flowers. It has only been recorded from the Carnarvon National Park.

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

Prasophyllum maccannii, commonly known as the inland leek orchid, is a species of orchid endemic to Victoria. It has a single tubular green leaf and up to forty green, greenish-pink or brownish flowers. It is found in the central-west of the state, growing in open forest.

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

Prasophyllum morganii, commonly known as the Cobungra leek orchid, is a species of orchid endemic to a small area in Victoria. It has a single tubular leaf and up to eighty greenish flowers with purplish markings. Before being rediscovered in 2020, the plant had last been seen in 1933 and was presumed extinct.

Prasophyllum pallidum, commonly known as the pale leek orchid, is a species of orchid endemic to a south-eastern South Australia. It has a single tubular leaf and up to thirty green or yellowish-green flowers. It was previously thought to occur in Victoria but records from that state are now recognised as P. roseum.

Prasophyllum parviflorum, commonly known as the slender leek orchid, is a species of orchid endemic to eastern Victoria. It has a single tubular leaf and up to thirty greenish-brown to purplish flowers. Further studies of the species may indicate that some collections currently included may be of a different species.

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 readii, commonly known as the Streathem leek orchid, is a species of orchid endemic to Victoria. It has a single, tubular leaf and up to twenty five scented, greenish-brown to reddish-brown flowers with a white or pinkish labellum and is only known from a swamp in the south-west of the state.

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.

Prasophyllum roseum, commonly known as the pink lip leek orchid, is a species of orchid endemic to southern continental Australia. It has a single tube-shaped leaf and up to thirty greenish flowers with a pink labellum. It is a recently described plant, previously included with P. fitzgeraldii, but distinguished from that species by its smaller, less crowded flowers, with more spreading lateral sepals and different labellum callus. It grows in the south-east of South Australia and in western Victoria.

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.

References

  1. 1 2 "Prasophyllum subbisectum". APNI. Retrieved 29 December 2017.
  2. 1 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. 214. ISBN   978-1877069123.
  3. 1 2 Jeanes, Jeff. "Prasophyllum subbisectum". Royal Botanic Gardens Victoria. Retrieved 29 December 2017.
  4. 1 2 3 "Approved conservation advice - Prasophyllum subbisectum (Pomonal leek-orchid)" (PDF). Australian Government Department of the Environment. Retrieved 29 December 2017.
  5. Nicholls, William H. (1936). "A new species of the genus Prasophyllum R.Br". The Victorian Naturalist. 53 (4): 72–74. Retrieved 8 December 2017.
  6. 1 2 3 Brown, Roland Wilbur (1956). The Composition of Scientific Words. Washington, D.C.: Smithsonian Institution Press.