Prasophyllum australe, commonly known as southern leek orchid[1] or austral leek orchid,[2] 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.
Prasophyllum australe is a terrestrial, perennial, deciduous, herb with an underground tuber and a single green, tube-shaped leaf up to 350sigfig=1NaNsigfig=1 long and 8sigfig=1NaNsigfig=1 in diameter near its reddish base. Up to fifty or more highly scented flowers are arranged along NaNsigfig=1NaNsigfig=1 of a thin flowering spike NaNsigfig=1NaNsigfig=1 high. The flowers are greenish-brown with white reddish stripes and are often sweetly fragrant.[3] As with others in the genus, the flowers are inverted so that the labellum is above the column rather than below it. The ovary is NaNsigfig=1NaNsigfig=1 long and pressed against the flowering stem. The lateral sepals are about 6sigfig=1NaNsigfig=1 long, joined for most of their length and form the uppermost part of the flower. The dorsal and lateral sepals and the petals are similar in size and shape, lance-shaped to egg-shaped, NaNsigfig=1NaNsigfig=1 long, but the lateral sepals are joined at their sides. The labellum is white, about 8sigfig=1NaNsigfig=1 long and 2sigfig=1NaNsigfig=1 wide, curves upwards and has a wavy margin. Flowering occurs from September to January and is more prolific after fire the previous summer.[4]
Prasophyllum australe was first formally described in 1810 by Robert Brown and the description was published in Prodromus Florae Novae Hollandiae et Insulae Van Diemen.[5] [6] The specific epithet (australe) is a Latin word meaning "south".[7]
The southern leek orchid grows in swampy places in forest and heath in south-eastern Queensland, near-coastal New South Wales, southern Victoria, south-eastern South Australia and in Tasmania.[8]