Caladenia lowanensis, commonly known as Wimmera spider orchid, is a plant in the orchid family Orchidaceae and is endemic to Victoria, Australia. It is a ground orchid with a single leaf and a single cream-coloured flower with red lines and blotches. The total population of this orchid was estimated in 2010 to be only about 700 plants but most are protected in reserves.
Caladenia lowanensis is a terrestrial, perennial, deciduous, herb with a spherical underground tuber. It has a single leaf, NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide. A single flower NaNsigfig=1NaNsigfig=1 wide is borne on a spike NaNsigfig=1NaNsigfig=1 tall. The flowers are cream-coloured with red streaks and blotches. The sepals have flattened, club-like, dark red glandular tips NaNsigfig=1NaNsigfig=1 long. The dorsal sepal is erect, NaNsigfig=2NaNsigfig=2 long and 2.3sigfig=1NaNsigfig=1 wide. The lateral sepals are NaNsigfig=2NaNsigfig=2 long, NaNsigfig=2NaNsigfig=2 wide and spread widely, sometimes curved downwards. The petals are NaNsigfig=1NaNsigfig=1 long, about 2sigfig=1NaNsigfig=1 wide and arranged like the lateral sepals. The labellum is egg-shaped, NaNsigfig=1NaNsigfig=1 long, NaNsigfig=1NaNsigfig=1 wide and pale yellowish with red streaks and a red tip which is curled under. The sides of the labellum have linear teeth up to 2sigfig=1NaNsigfig=1 long and there are four or six well-spaced rows of shiny red calli along its mid-line but not extending to the tip. Flowering occurs in September and October.[1] [2] [3]
Caladenia lowanensis was first formally described in 1991 by Geoffrey Carr from a specimen collected near Kiata and the description was published in Indigenous Flora and Fauna Association Miscellaneous Paper 1.[4] The specific epithet (lowanensis) is derived from the Lowan district of Victoria with the Latin suffix -ensis meaning "of" or "from"[5] referring to the distribution of this orchid species.[6]
The Wimmera spider orchid grows in sparse woodland near Kiata, in and near the Little Desert National Park.
Caladenia lowanensis is listed as "endangered" under the Victorian Flora and Fauna Guarantee Act 1988 and under the Australian Government Environment Protection and Biodiversity Conservation Act 1999. In 2010 the known population of this species was 700 plants in five populations but about 90% of these were protected in reserves. The main threats to the species are rubbish dumping, trampling, weed invasion and grazing by rabbits (Oryctolagus cuniculus).[7]