Prasophyllum laxum
From Wikipedia, the free encyclopedia
| Lax leek orchid | |
|---|---|
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Monocots |
| Order: | Asparagales |
| Family: | Orchidaceae |
| Subfamily: | Orchidoideae |
| Tribe: | Diurideae |
| Subtribe: | Prasophyllinae |
| Genus: | Prasophyllum |
| Species: | P. laxum |
| Binomial name | |
| Prasophyllum laxum | |
Prasophyllum laxum, commonly known as the lax leek orchid, is a species of orchid endemic to a small region of South Australia. It has a single tubular leaf and up to twenty pale green, tan and lilac-coloured flowers. It was first collected in the 1960s in a location known as the Hundred of Koppio on the Eyre Peninsula but was not described until 2008 from a new collection in 2004.
Prasophyllum laxum is a terrestrial, perennial, deciduous, herb with an underground tuber and a single loosely erect, tube-shaped leaf up to 300 mm (10 in) long and 4 mm (0.2 in) wide. The flowering stem emerges from the leaf 100–200 mm (4–8 in) above the ground. Between five and twenty strongly scented flowers are irregularly arranged along a drooping flowering stem up to 60 mm (2 in) long. The flowers are pale green on the inside, tan-coloured on the outside and as with others in the genus, are inverted so that the labellum is above the column rather than below it. The ovary is oval-shaped, erect, 4–5 mm (0.16–0.20 in) long and 2–3 mm (0.08–0.1 in) wide. The dorsal sepal is egg-shaped to lance-shaped, 6–7 mm (0.2–0.3 in) long, about 1 mm (0.04 in) wide and points downwards. The lateral sepals are a similar size to the dorsal sepal, linear to lance-shaped and free from each other. The petals are linear in shape, about 4 mm (0.2 in) long, 1 mm (0.04 in) wide and pale green with white edges. The labellum is egg-shaped, very pale pink, 5 mm (0.2 in) long, about 2 mm (0.08 in) wide and curves gently upwards then the tip curves forwards. There is a green, channelled callus in the centre of the labellum. Flowering occurs in late September and October but the flowers are short-lived.[2]
Taxonomy and naming
Prasophyllum laxum was first formally described in 2008 by Robert John Bates and the description was published in Journal of the Adelaide Botanic Gardens from a specimen collected near Wanilla.[1] The specific epithet (laxum) is a Latin word meaning "loose" or "slack"[3] referring to the loosely erect leaf and flowering stem.[2]
Distribution and habitat
The lax leek orchid is only known from a single hill between Koppio and Wanilla on the Eyre Peninsula. It grows in sparse woodland.[2]
