Corunastylis nigricans
# Corunastylis nigricans

Corunastylis nigricans, commonly known as the Kangaroo Island midge orchid is a small terrestrial orchid endemic to South Australia. It has a single thin leaf and up to twenty five purplish brown flowers with a shiny, hairless, dark purplish labellum. It is sometimes confused with Genoplesium nigricans which has differently coloured flowers and a much wider distribution. It is regarded as a synonym of G. nigricans by the World Checklist of Selected Plant Families.

## Description

Corunastylis nigricans is a terrestrial, perennial, deciduous, herb with an underground tuber and a single thin leaf 100–200 mm (4–8 in) long with the free part 10–15 mm (0.4–0.6 in) long, ending below the flowering stem. Between five and twenty five flowers are crowded along a flowering stem 10–25 mm (0.4–1 in) tall. The flowers are brownish purple, turn slightly downwards and are about 7 mm (0.3 in) long and 5 mm (0.2 in) wide. As with others in the genus, the flowers are inverted so that the labellum is above the column rather than below it. The dorsal sepal is about 3.5 mm (0.1 in) long, 2 mm (0.08 in) wide with hairless edges. The lateral sepals are about 4 mm (0.2 in) long, 1 mm (0.04 in) wide, free from each other and spread widely apart. The petals are linear in shape, about 3 mm (0.1 in) long and 0.5 mm (0.02 in) wide with hairless edges. The labellum is oblong to egg-shaped with the narrower end towards the base, thick and fleshy, about 3 mm (0.1 in) long and 1.5 mm (0.06 in) wide with a blunt tip. Flowering occurs between February and May.

## Taxonomy and naming

The Kangaroo Island leek orchid was first formally described in 1810 by Robert Brown who gave it the name Prasophyllum nigricans and published the description in Prodromus Florae Novae Hollandiae et Insulae Van Diemen. In 2002, David Jones and Mark Clements changed the name to Corunastylis nigricans. The specific epithet nigricans is a Latin word meaning "blackish".

## Distribution and habitat

Corunastylis nigricans grows in dry forest and coastal scrub on Kangaroo Island and the Eyre Peninsula.

