It has a single hollow, onion-like leaf and up to fifty scented, bright green flowers.

Microtis oblonga is a terrestrial, perennial, deciduous, herb with an underground tuber and a single erect, smooth, tubular leaf 200–600 mm (8–20 in) long and 6–8 mm (0.2–0.3 in) wide.

[2] Microtis oblonga was first formally described in 1923 by Richard Sanders Rogers and the description was published in Transactions and Proceedings of the Royal Society of South Australia.

[3][4] It is regarded by many Australian authorities as being a synonym of Microtis rara.

[3][5][6][7] The specific epithet (oblonga) is a Latin word meaning "longer than broad".