A common, widespread orchid which is easily grown in pots and is sometimes a weed in plant nurseries.

Microtis unifolia is a terrestrial, perennial, deciduous, herb with an underground tuber and a single hollow, green leaf which is 100–800 mm (4–30 in) long.

The ovary is more or less oval in shape, 3–4 mm (0.1–0.2 in) long on a short, relatively thick pedicel and stands out from the stem.

Flowering occurs from October to January in Australia, but somewhat later in New Zealand[2][3] The common onion orchid was first formally described in 1786 by Georg Forster, who gave it the name Ophrys unifolia and published the description in Florulae Insularum Australium Prodromus.

[7]: 466 Microtis unifolia occurs in a wide range of habitats from swamps to rocky outcrops in semi-arid areas.