It is a small orchid only known from a few sites near the towns of Tallong and Wingello on the Southern Tablelands and is only relatively easy to find for about a month, when it flowers.

Genoplesium plumosum is a terrestrial, perennial, deciduous, sympodial herb, usually with a few inconspicuous, fine roots and a pair of more or less spherical tubers.

The tubers are partly covered by a protective fibrous sheath which extends to the soil surface.

[10] Tallong midge-orchid grows among low shrubs in forest and in moss gardens over sandstone mainly between Sydney Harbour and Marulan.

The main reasons for its decline have been land clearing and grazing by the introduced European Rabbit (Oryctolagus cuniculus).