Caladenia exilis subsp. vanleeuwenii, commonly known as the Moora spider orchid, is a plant in the orchid family Orchidaceae and is endemic to the south-west of Western Australia. It is a relatively rare spider orchid with a single erect, hairy leaf and up to three variably-coloured flowers with a small white, red-striped labellum. It differs from subspecies exilis in having variably coloured flowers, different growth habit, earlier flowering and different habitat.
Caladenia exilis subsp. vanleeuwenii is a terrestrial, perennial, deciduous, herb with an underground tuber which grows singly or in small tufts. It has a single erect, hairy leaf, NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide. Up to three flowers NaNsigfig=1NaNsigfig=1 long and NaNsigfig=2NaNsigfig=2 wide are borne on a spike NaNsigfig=1NaNsigfig=1 tall. The flowers are white, red, pale yellow or cream-coloured. The dorsal sepal is erect, NaNsigfig=1NaNsigfig=1 long and about 2sigfig=1NaNsigfig=1 wide and tapers to a dark, thread-like tip. The lateral sepals and petals are more or less drooping with long, dark, thread-like tips. The lateral sepals are less than NaNsigfig=1NaNsigfig=1 long, about 3sigfig=1NaNsigfig=1 wide at the base and the petals are NaNsigfig=1NaNsigfig=1 long and about 2sigfig=1NaNsigfig=1 wide at the base. The labellum is NaNsigfig=1NaNsigfig=1 long, NaNsigfig=1NaNsigfig=1 wide and white or cream-coloured with red lines and spots. The edge of the labellum has short, forward-facing teeth and there are two rows of red to cream-coloured calli along its centre. Flowering occurs from June to August.[1] [2] [3]
Caladenia exilis subsp. vanleeuwenii was first formally described in 2001 by Stephen Hopper & Andrew Brown and the description was published in Nuytsia.[4] The specific epithet (vanleeuwenii) honours Steven van Leeuwen, an Australian research scientist who first recognised the species as distinct.
Moora spider orchid occurs between Watheroo and Wongan Hills in the Avon Wheatbelt and Jarrah Forest biogeographic regions where it grows in York gum and salmon gum forests which are wet in winter.
Caladenia exilis subsp. vanleeuwenii is classified as "not threatened" by the Western Australian Government Department of Parks and Wildlife.