Diuris littoralis, commonly known as Green Range donkey orchid, is a species of orchid that is endemic to the south-west of Western Australia. It has two or three linear leaves and up to six yellow, brown and mauve flowers from late July to early September.
Diuris littoralis is a tuberous, perennial herb with two or three linear leaves long and wide. Up to six yellow flowers with brown and mauve markings, long and wide are borne on a flowering stem tall. The dorsal sepal is egg-shaped, long and wide, the lateral sepals narrowly oblong, parallel or crossed, long and wide. The petals are more or less broadly elliptic, long and wide on a stalk long. The labellum is long with three lobes - the centre lobe wedge-shaped with down-curved edges, long and wide, the side lobes spread widely apart and oblong, long and wide. There is a single smooth, yellow callus ridge along the mid-line of the labellum. Flowering occurs from late July to early September.[1] [2]
Diuris littoralis was first formally described in 2016 by David Jones and Christopher J. French in Australian Orchid Review, from a specimen collected by Jones near the hospital in Spencer Park in 1986.[3] The specific epithet (littoralis) means "belonging to the sea shore", referring to the coastal or near-coastal habitat of this species.[4]
Green Range donkey orchid grows in coastal and near-coastal shrublands and woodlands on well-drained laterite, in clay near streams and in shallow sand over limestone between Denmark and Esperance in the Avon Wheatbelt, Esperance Plains, Jarrah Forest and Mallee bioregions of south-western Western Australia.
Diuris littoralis is listed as "not threatened" by the Western Australian Government Department of Biodiversity, Conservation and Attractions.