Prasophyllum unicum

Prasophyllum unicum is a terrestrial, perennial, deciduous, herb with an underground tuber and a single leaf sheathing the flowering stem at the base. Between two and fifteen flowers are arranged on a flowering stem 100–130 mm (3.9–5.1 in) high. The flowers are inverted so that the labellum is above the column rather than below it. The dorsal sepal is about 3 mm (0.12 in) long and oblong, narrowing to a long, thread-like tip, and barely forming a hood over the column. The lateral sepals are lance-shaped, about 5 mm (0.20 in) long and swollen at the base. The petals are narrow, shorter than the dorsal sepal with a fine, thread-like tip. The labellum is spatula-shaped with a thread-like tip, and a two thick, parallel, dark reddish calli.[2]

Prasophyllum unicum was first formally described in 1942 by Herman Montague Rupp in The Victorian Naturalist from specimens collected in Normanhurst in the same year.[2][3] The name is accepted at Plants of the World Online[1] but is considered a synonym of Corunastylis rufa at the Australian Plant Census.[4] The specific epithet (unica) means "unique", "because it stands alone among all forms hitherto described".[2]

Prasophyllum unicum occurs in New South Wales.[1]