Corybas pruinosus, commonly known as the toothed helmet orchid, is a species of terrestrial orchid endemic to New South Wales. It grows in moist forests and has a single round or heart-shaped leaf and a relatively small, translucent grey flower with dark red markings.
Corybas pruinosus is a terrestrial, perennial, deciduous, herb with a single round or heart-shaped leaf NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide. The leaf is green on the upper surface and silvery green on the lower side. There is a single translucent grey flower with dark red markings. The dorsal sepal is NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide curves forward over the labellum. The lateral sepals are linear, NaNsigfig=1NaNsigfig=1 long and 1sigfig=1NaNsigfig=1 wide and the petals are about 6sigfig=1NaNsigfig=1 long and 1sigfig=1NaNsigfig=1 wide, often with two points on the tip. The labellum is NaNsigfig=1NaNsigfig=1 long and NaNsigfig=2NaNsigfig=2 wide with a greyish mound in the cente, many short bristles and its edges with many long, narrow teeth. Flowering occurs from April to July.[1] [2]
The toothed helmet orchid was first formally described in 1871 by Richard Cunningham and given the name Corysanthes pruinosa. The description was published in the New South Wales Magazine.[3] In 1871, Heinrich Gustav Reichenbach changed the name to Corybas pruinosus.[4] The specific epithet (pruinosus) is a Latin word meaning "frosty" or "rimy".[5]
The toothed helmet orchid grows in forest with shrubs between Nelson Bay, Moruya and Paterson.