Genoplesium ruppii is a terrestrial, perennial, deciduous, herb with an underground tuber and a single thin leaf 100–180 mm (4–7 in) long and fused to the flowering stem with the free part 8–15 mm (0.3–0.6 in) long.

There is a small callus in the centre of the labellum and extending about halfway to its tip.

[2] Rupp's midge orchid was first formally described in 1927 by Richard Sanders Rogers who gave it the name Prasophyllum ruppii.

The type specimen was collected near Paterson by Herman Rupp and the description was published in Transactions and Proceedings of the Royal Society of South Australia.

[1][6] Genoplesium ruppii grows in swampy and grassy sites and in heathy forest.