Caladenia speciosa, commonly known as the sandplain white spider orchid, is a species of orchid endemic to the south-west of Western Australia. It has a single erect, hairy leaf and up to three relatively large white flowers tinged with pink and with a fringe of long teeth on the sides of the labellum.
Caladenia speciosa is a terrestrial, perennial, deciduous, herb with an underground tuber and a single erect, hairy leaf, NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide. Up to three flowers NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide are borne on a stalk NaNsigfig=1NaNsigfig=1 tall. The flowers are white, often with a pink or red tinge. The sepals and petals have long, thin, brownish thread-like tips. The dorsal sepal is erect, NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide. The lateral sepals are NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide, spread widely and horizontally near their base but then curve downwards. The petals are NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide and arranged like the lateral sepals. The labellum is NaNsigfig=1NaNsigfig=1 long, NaNsigfig=1NaNsigfig=1 wide and white but with erect, narrow red teeth up to 15sigfig=1NaNsigfig=1 long on the sides. The tip of the labellum is curled under and there are between four and six rows of pink or white calli along the mid-line of the labellum. Flowering occurs from September to October but is more prolific after fire the previous summer.[1] [2] [3]
Caladenia speciosa was first formally described in 2001 by Stephen Hopper and Andrew Phillip Brown from a specimen collected near Bunbury and the description was published in Nuytsia.[4] The specific epithet (speciosa) is a Latin word meaning "beautiful", "handsome", "splendid" or "showy"[5] referring to the "large, attractive flowers" of this orchid.
The sandplain white spider orchid is found between Mundijong and Boyanup in the Jarrah Forest and Swan Coastal Plain biogeographic regions where it grows in woodland.
Caladenia speciosa is classified as "Priority Four" by the Government of Western Australia Department of Parks and Wildlife, meaning that is rare or near threatened.[6]