Genoplesium sagittiferum is a terrestrial, perennial, deciduous, herb with an underground tuber and a single thin leaf 50–100 mm (2–4 in) long and fused to the flowering stem with the free part 10–15 mm (0.4–0.6 in) long.

There is a tapered, dark red callus in the centre of the labellum and extending nearly to its tip.

[2][3] The horned midge orchid was first formally described in 1942 by Herman Rupp who gave it the name Prasophyllum sagittiferum.

The type specimen was collected near Bell by Erwin Nubling[4] and his wife and the description was published in The Victorian Naturalist.

[6] Genoplesium sagittiferum grows with shrubs in sandy soils, sometimes in moss gardens on rock ledges.