Genoplesium validum, commonly known as the Blackdown midge orchid, is a species of small terrestrial orchid that is endemic to the Blackdown Tableland National Park in Queensland. It has a single thin leaf fused to the flowering stem and up to thirty five greenish-brown flowers with reddish stripes and a hairy labellum. This species is treated as Corunastylis valida in Queensland.
Genoplesium validum is a terrestrial, perennial, deciduous, herb with an underground tuber and a single thin leaf with a reddish base and NaNsigfig=1NaNsigfig=1 long, fused to the flowering stem with the free part NaNsigfig=2NaNsigfig=2 long. Between fifteen and thirty five flowers are arranged along a flowering stem NaNsigfig=2NaNsigfig=2 long, reaching to a height NaNsigfig=1NaNsigfig=1. The flowers lean downwards, are greenish-brown, about 6sigfig=1NaNsigfig=1 long and 4sigfig=1NaNsigfig=1 wide. As with others in the genus, the flowers are inverted so that the labellum is above the column rather than below it. The dorsal sepal is elliptic to narrow egg-shaped, about 4.5sigfig=1NaNsigfig=1 long, 2sigfig=1NaNsigfig=1 wide and greenish with narrow, dark purplish bands. The lateral sepals are linear to lance-shaped, about 5sigfig=1NaNsigfig=1 long, 1sigfig=1NaNsigfig=1 wide and spread widely apart from each other. The petals are linear to egg-shaped, about 3.5sigfig=1NaNsigfig=1 long and 1sigfig=1NaNsigfig=1 wide with dark purplish bands. The labellum is elliptic to broadly oblong, about 3sigfig=1NaNsigfig=1 long, 1.5sigfig=1NaNsigfig=1 wide and dark purplish-black with its edges densely covered with short, coarse purplish hairs. There is a dark purplish-black callus in the centre of the labellum and extending almost to its tip. Flowering occurs from December to April.[1] [2]
Genoplesium validum was first formally described in 1991 by David Jones and the description was published in Australian Orchid Research.[3] In 2002, David Jones and Mark Clements changed the name to Corunastylis valida, a name that is accepted in Queensland but not by the Australian Plant Census.[4] The specific epithet (validum) is a Latin word meaning "strong" or "powerful",[5] referring to the robust habit of this orchid.
The Blackdown midge orchid grows in sandy soil in rocky places on the Blackdown Tableland.