Caladenia uliginosa subsp. uliginosa, commonly known as the dainty spider orchid, or darting spider orchid is a plant in the orchid family Orchidaceae and is endemic to the south-west of Western Australia. It has a single hairy leaf and up to four greenish-cream flowers which have a forward-projecting labellum with a dark red tip.
Caladenia uliginosa subsp. uliginosa is a terrestrial, perennial, deciduous, herb with an underground tuber and a single erect, hairy leaf, 100âÂÂ160 mm long and 8âÂÂ10 mm wide. Up to four greenish-cream flowers 80âÂÂ120 mm long and 40âÂÂ60 mm wide are borne on a spike 200âÂÂ350 mm tall. The sepals and petals have brownish, thread-like tips. The sepal is erect, 45âÂÂ100 mm long and about 2 mm wide and the lateral sepals are 45âÂÂ100 mm long, 4âÂÂ5 mm wide and curve downwards. The petals are 35âÂÂ80 mm long and about 3 mm wide and also curve downwards. The labellum is 14âÂÂ22 mm long, 7âÂÂ10 mm wide, cream-coloured and projects forward with a dark red tip. The side of the labellum have thin, red, erect teeth up to 2.5 mm long, its tip curves downward and there are four rows of red calli along its centre. Flowering occurs from late September to early November.
Caladenia uliginosa was first described in 1984 by Alex George from a specimen collected near Frankland and the description was published in Nuytsia. In 2001, Stephen Hopper and Andrew Phillip Brown described three subspecies, including subspecies uliginosa and the description was also published in Nuytsia. The specific epithet (uliginosa) is a Latin word meaning "full of moisture", "wet" or "marshy" referring to the swampy habitat where this orchid usually grows.
The dainty spider orchid is found between Boddington and Mount Barker in the Jarrah Forest and Swan Coastal Plain biogeographic regions where it grows in moist forest and areas that are wet in winter.
Caladenia uliginosa subsp. uliginosa is classified as "not threatened" by the Western Australian Government Department of Parks and Wildlife.