Microtis rara

Microtis rara, commonly known as the scented onion orchid, is a species of orchid endemic to Australia, with the exception of the Northern Territory. It has a single hollow, onion-like leaf and up to fifty small green or yellowish-green, scented flowers. It is similar to Microtis oblonga and some authorities regard the two as being one species.

Description
Microtis rara is a terrestrial, perennial, deciduous, herb with an underground tuber and a single erect, tapering, tubular leaf 200-500 mm long and 3-5 mm wide. Between ten and fifty green or greenish-yellow flowers are well spaced along a flowering stem 30-160 mm tall. The flowers sweetly scented, 5-6 mm long and 2-2.5 mm wide. The dorsal sepal is egg-shaped, 3-4 mm long, 1.5-2 mm wide with a dished lower surface. The lateral sepals are linear to oblong, 2-3 mm long, about 1 mm wide with their tips rolled under. The petals are a curved lance shape, 2-2.5 mm long, about 1 mm wide and spread widely apart. The labellum is more or less oblong, 3-4 mm long, 1-1.5 mm wide with notched edges and a narrowed middle section. There are dark green calli in the centre of the labellum. Flowering occurs from November to January and is stimulated by fire the previous summer.

Taxonomy and naming
Microtis rara was first formally described in 1810 by Robert Brown and the description was published in Prodromus Florae Novae Hollandiae et Insulae Van Diemen. The specific epithet (rara) is a Latin word meaning "scarce", "scattered" or "dispersed".

Some authorities regard Microtis oblonga as being a race of M. rara.

Distribution and habitat
The scented onion orchid grows swamps and wet forests and is widespread but not common, occurring in all states but not the Northern Territory.