It has a single thin leaf and up to ten dark purple flowers with darker stripes and a hairy labellum which vibrates in the slightest breeze.

Genoplesium fimbriatum is a terrestrial, perennial, deciduous, herb with an underground tuber and a single thin leaf 150–280 mm (6–10 in) long with the free part 10–22 mm (0.4–0.9 in) long.

[2] Genoplesium ostrinum was first formally described in 2001 by David Jones and the description was published in The Orchadian.

[1][4] The specific epithet (ostrinum) is a Latin word meaning "purple".

[5] The purple midge orchid grows with shrubs or grasses in woodland between Tallong and Braidwood.