Pterostylis calceolus, commonly known as the Bungonia rustyhood, is a plant in the orchid family Orchidaceae and is endemic to New South Wales. It has a rosette of overlapping leaves and between two and seven reddish-brown flowers with transparent "windows" and a fleshy brown, insect-like labellum. It is only known from near Bungonia.
Pterostylis calceolus, is a terrestrial, perennial, deciduous, herb with an underground tuber and a rosette of between four and six egg-shaped leaves, NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide. Flowering plants have between two and seven reddish-brown flowers with transparent sections, each flower NaNsigfig=1NaNsigfig=1 long, NaNsigfig=1NaNsigfig=1 wide. The flowers are borne on a flowering spike NaNsigfig=1NaNsigfig=1 tall with between two and four stem leaves wrapped around it. The dorsal sepal and petals form a hood or "galea" over the column with the dorsal sepal having a downturned, thread-like point NaNsigfig=1NaNsigfig=1 long. The lateral sepals are NaNsigfig=1NaNsigfig=1 long, NaNsigfig=1NaNsigfig=1 wide, turn downwards and joined for about half their length. The lateral sepals are dished and suddenly narrow to thread-like tips NaNsigfig=1NaNsigfig=1 long which curve forwards with hooked ends. The labellum is brown, fleshy, insect-like, about 5sigfig=1NaNsigfig=1 long, 2sigfig=1NaNsigfig=1 wide and egg-shaped with short bristles on the "head" end and eight to ten pairs of longer bristles on the "body". Flowering occurs from October to November.[1] [2]
Pterostylis calceolus was first formally described in 1989 by Mark Clements from a specimen collected in Bungonia Gorge and the description was published in Australian Orchid Research.[3] The specific epithet (calceolus) refers to the outline of the labellum which resembles a slipper or shoe of the type worn in the middle-ages.[4]
The Bungonia rustyhood is only known from the Bungonia district where it grows in forest and woodland.