Caladenia venusta, commonly known as the graceful spider orchid, large white spider orchid, or simply white spider orchid is a plant in the orchid family Orchidaceae and is endemic to southern Australia. It is a ground orchid with a single leaf and one or two white to cream-coloured flowers with drooping, brown, thread-like tips.
Caladenia venusta is a terrestrial, perennial, deciduous, herb with an underground tuber and a single leaf, 100âÂÂ180 mm long and 8âÂÂ12 mm wide. One or two white to cream-coloured flowers 80âÂÂ120 mm wide are borne on a spike 200âÂÂ600 mm high. The sepals and petals have rather thick, brown thread-like tips. The sepal is erect, 60âÂÂ100 mm long and 2âÂÂ4 mm wide. The sepals are 60âÂÂ100 mm long, 4âÂÂ8 mm wide, spread apart from each other and have drooping tips. The petals are 50âÂÂ80 mm long, 3âÂÂ6 mm wide and also have drooping tips. The labellum is white or cream-coloured with its tip rolled under and sides turned upwards. There are many thin, reddish teeth up to 3.5 mm long on the side of the labellum and four or six rows of narrow, reddish foot-shaped calli up to 2 mm long along its mid-line with the longest ones near its base. Flowering occurs from September to November.
Caladenia venusta was first formally described in 1991 by Geoffrey Carr and the description was published in Indigenous Flora and Fauna Association Miscellaneous Paper 1. The specific epithet (venusta) is a Latin word meaning "lovely", "beautiful", "elegant" or "graceful".
The graceful spider orchid is most common in Victoria but even in that state it is rare, usually occurring in coastal woodland but is also found in the Grampians. It has been found in the far south-east of South Australia and may occur on the south-west slopes of New South Wales.