Corybas incurvus, commonly known as the slaty helmet orchid, is a species of terrestrial orchid endemic to south-eastern Australia. It has a broad egg-shaped to heart-shaped leaf and a dark purple flower with a white patch in the middle.
Corybas incurvus is a terrestrial, perennial, deciduous, herb that has a broad egg-shaped to heart-shaped leaf NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide. The leaf is dark green on the upper surface and silvery green on the lower side. The single flower is dark purple, NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide. The dorsal sepal is greenish with purple markings, NaNsigfig=1NaNsigfig=1 long, NaNsigfig=2NaNsigfig=2 wide and curves forward forming a hood over the labellum. The lateral sepals are linear, about 5sigfig=1NaNsigfig=1 long, 0.5sigfig=1NaNsigfig=1 wide and joined at their base. The petals are about 3sigfig=1NaNsigfig=1 long, 0.5sigfig=1NaNsigfig=1 wide, often with tip divided into two. The labellum is tube shaped near its base, the tube about NaNsigfig=1NaNsigfig=1 long, then opens into a flattened area a further NaNsigfig=1NaNsigfig=1 long and broad. There is a white patch in the centre of the labellum and the edges turn inwards and have a few short teeth. Flowering occurs from June to August.[1] [2] [3]
Corybas incurvus was first formally described in 1988 by David Jones and Mark Clements from a specimen collected near Tyabb and the description was published in the Kew Bulletin.[4] [5] The specific epithet (incurvus) refers to the in-turned edges of the labellum.
The slaty helmet orchid grows in moist heath, woodland and forest south from Cowra in New South Wales, in all but the north-west of Victoria, in the south-east of South Australia and in Tasmania.