Microtis arenaria


Microtis arenaria, commonly known as the notched onion orchid or pale onion orchid, is a species of orchid native to south-eastern Australia and New Zealand. It has a single hollow, onion-like leaf and up to sixty scented, crowded yellowish-green flowers. It is widespread and common, growing in a wide variety of habitats.

Description

Microtis arenaria is a terrestrial, perennial, deciduous, herb with an underground tuber and a single erect, smooth, tubular leaf long and wide. Between ten and sixty yellowish-green, fragrant flowers are crowded along a flowering stem tall. The flowers are long and wide. The dorsal sepal is egg-shaped, long and wide with its tip turned slightly upwards. The lateral sepals are long, about wide with their tips rolled under. The petals are lance-shaped but curved, about long, wide and are held under the dorsal sepal. The labellum curves downwards and is long, about wide with scalloped edges and a shallow notch at the tip between two prominent lobes. There is an irregularly-shaped callus in the centre of the labellum. Flowering occurs from September to January.

Taxonomy and naming

Microtis arenaria was first formally described in 1840 by John Lindley and the description was published in The Genera and Species of Orchidaceous Plants. The specific epithet is a Latin word meaning "sandy".

Distribution and habitat

The pale onion orchid is widespread and common in south-eastern New South Wales, throughout Victoria, Tasmania and south-eastern South Australia. It grows in a range of habitats from sandhills to rocky inland outcrops but is most common in coastal sand. Microtis arenaria also occurs on the North Island of New Zealand.