Orchids in the genus Pyrorchis are terrestrial, perennial, deciduous, sympodial herbs with a few inconspicuous, fine roots and an oval-shaped tuber lacking a protective sheath.

[1][2][3][4][5]Robert Brown first formally described Lyperanthus nigricans in 1810, publishing the description in Prodromus Florae Novae Hollandiae.

[10]: 577 [9] There are two species: Pyrorchis forrestii is only found in the south-west of Western Australia between Augusta and Waychinicup National Park where it grows near the margins of swamps or near creeks.

In drier areas of Western Australia, it is usually found in moist places near granite outcrops.

[4][5][11] Both species of Pyrorchis produce small amounts of nectar and have a strong, sweet smell, especially in hot weather, suggesting pollination by bees although only P. forrestii has brightly coloured flowers.