Prasophyllum, commonly known as leek orchids, is a genus of about 140 species of flowering plants in the orchid family, Orchidaceae and is found in Australia and New Zealand. The Australian species are found in all states but have not been recorded in the Northern Territory. The common name arises from their having a hollow, leek- or onion-like leaf. Some species only flower after summer fires and have flowers similar to those of Xanthorrhoea which flower at the same time, suggesting that they employ the same pollinating insects. Leek orchids are similar to those in the genus Genoplesium except that the free part of the leaf is cylindrical and the labellum has a solid connection to the column. They range in size from the little laughing leek orchid at about 15 cm (6 in) to the king leek orchid which grows up to 2 m (80 in) tall.
Prasophyllum correctum, commonly known as the gaping leek orchid or Bairnsdale leek orchid, is a species of orchid species endemic to a small region in Victoria. It has a single dark green, tube-shaped leaf and up to twenty strongly scented, yellowish-green flowers and is only known from railway reserves near Bairnsdale.
Prasophyllum calcicola, commonly known as the limestone leek orchid, is a species of orchid endemic to Australia. It has a single, smooth, tube-shaped leaf and up to twelve yellowish-green flowers on an erect flowering stem. It is found in coastal areas of Western Australia and South Australia growing on soils derived from limestone.
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.
Prasophyllum colensoi is a species of orchid endemic to New Zealand where it is commonly known as the leek orchid. It has a single tubular, dark green leaf and up to twenty scented, yellowish-green to reddish-brown flowers. It is similar to P. hectori, the only other species of Prasophyllum found in New Zealand, but is distinguished from it by its smaller size, fewer flowers and different habitat.
Prasophyllum cucullatum, commonly known as the hooded leek orchid, is a species of orchid endemic to the south-west of Western Australia. It is a tall orchid with a single smooth, tubular leaf and up to fifty or more purplish-red and white flowers with a frilled labellum crowded along a relatively short flowering stem.
Prasophyllum cyphochilum, commonly known as the pouched leek orchid, is a species of orchid endemic to the south-west of Western Australia. It is a relatively common orchid with a single smooth, tubular leaf and up to thirty or more pale yellow and brown flowers. The flowers do not open fully, are more or less cup-shaped and have a "humped" labellum.
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 litorale, commonly known as the coastal leek orchid, is a species of orchid endemic to southern continental Australia. It has a single tubular leaf and up to forty flowers with red and green colouring and grows in sandhills near the sea.
Prasophyllum macrostachyum, commonly known as the laughing leek orchid, is a species of orchid endemic to the south-west of Western Australia. It has a single smooth, tube-shaped leaf and up to thirty yellowish-green and purple flowers. It is one of the few Western Australian leek orchids which is not stimulated by summer fires and also has an unusually long flowering period.
Prasophyllum parvifolium, commonly known as the autumn leek orchid, is a species of orchid endemic to the south-west of Western Australia. It is a common species in its range and has a single smooth, tube-shaped leaf and up to eighteen or more green and white flowers with red stripes.
Prasophyllum ovale, commonly known as the little leek orchid, is a species of orchid endemic to the south-west of Western Australia. It is a small leek orchid with a single smooth, tubular leaf and up to twenty or more white, green and brown flowers with the labellum only slightly upturned.
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 paulinae, commonly known as Pauline's leek orchid, is a species of orchid endemic to the south-west of Western Australia. It is a small, rare leek orchid with a single smooth, tubular leaf and up to seventy yellowish-green and purple flowers.
Prasophyllum plumiforme, commonly known as the dainty leek orchid, is a species of orchid endemic to the south-west of Western Australia. It is a small leek orchid with a single smooth, tubular leaf and up to fifty or more tiny cream-coloured or greenish-yellow flowers on a tall flowering stem.
Prasophyllum regium, commonly known as the king leek orchid, is a species of orchid endemic to the south-west of Western Australia. It has a single, unusually thick tubular leaf and up to one hundred relatively large, greenish-brown or burgundy-coloured flowers. It is one of the tallest leek orchids, sometimes growing to a height of 2 m (7 ft).
Prasophyllum validum, commonly known as the Mount Remarkable leek orchid, is a species of orchid endemic to South Australia. It has a single tubular leaf and up to forty five green to yellowish-green flowers with a white labellum. A similar leek orchid occurring in Victoria, previously included in this species, is known recognised as the undescribed Prasophyllum sp. aff. validum.
Prasophyllum crassum is a species of orchid endemic to South Australia. It has a single tube-shaped leaf and up to fifteen greenish and pinkish-brown flowers with a whitish labellum. It is a recently described plant, previously included with P. fitzgeraldii, but distinguished from that species by its smaller number of smaller, less colourful flowers and different labellum shape. It grows in the south-east of the state and usually only appears after fire.
Prasophyllum occidentale, commonly known as the plains leek orchid, is a species of orchid endemic to southern continental Australia. It has a single tubular leaf and up to twenty five small, pale yellowish-green flowers. It is found in South Australia and Victoria although regarded by some taxonomists as a South Australian endemic.
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.
