It has a single hairy leaf and up to four, mostly white flowers with long drooping, thread-like ends on the sepals and petals.

longicauda is a terrestrial, perennial, deciduous, herb with an underground tuber and which sometimes grows as a solitary plant, otherwise in a small clump.

[1][2][3][4] Caladenia longicauda was first formally described by John Lindley in 1840 and the description was published in A Sketch of the Vegetation of the Swan River Colony.

[2] The white spider orchid is common to the south-west of a line between Lancelin and Mount Barker in the Avon Wheatbelt, Jarrah Forest, Mallee, Swan Coastal Plain and Warren biogeographic regions where it grows in woodland and forest.

longicauda is classified as "not threatened" by the Western Australian Government Department of Parks and Wildlife.