Polanisia dodecandra is a species of flowering plant in the Cleomaceae family, known by the common name redwhisker clammyweed or clammyweed, and there are three subspecies of Polanisia. Usually annual, occasionally perennial, Polanisia is native to North America, and is found throughout much of Canada and the United States. It favors full sun, mesic to dry conditions, and barren, sandy or gravelly soils, even highly disturbed areas where there is little other ground vegetation.  It looks similar to a close relative, the spider flower (Cleome).
The scientific name of the genus derives from the fact that the plant has numerous, long stamens of unequal lengths (from Greek polys, "many", and anisos, "unequal"). The name of the species, dodecandra means "having 12 stamens". The common name clammyweed refers to the sticky, or clammy, residue left on hands after handling the plant.
Polanisia grows from 30 to 91 cm (1 to 3 ft) tall and the vegetation and sap have a noticeable odor described as smelling unpleasant, sulphur-like, "strong and rank". The leaves, about 5.1 cm (2 in) long, are made up of three 2.5 centimetres (1 in) palmate leaflets. The stems are covered in glandular hairs, and numerous flowers are borne in terminal racemes (May–October). Each flower has four white or cream petals about 2.5 cm (1 in) long, and reddish purple stamens extend well beyond the petals (hence the "red whisker" clammyweed nomenclature). The seedpods are long, slender capsules 2.5–5.1 cm (1–2 in) long. They contain multiple small reddish brown seeds approx 2 mm (0.079 in). Polanisia seedpods project upward (whereas Cleome pods project out or down).
There are several subspecies of 'Polanisia dodecandra, including:
- Polanisia dodecandra subsp. dodecandra – redwhisker clammyweed
- P. dodecandra subsp. riograndensis – Rio Grande clammyweed (only found in Texas)
- P. dodecandra subsp. trachysperma – sandyseed clammyweed.
- "Polanisia dodecandra". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved 2011-02-01.
- "ITIS Standard Report Page: Cleomaceae". www.itis.gov. Retrieved 2019-07-26.
- "Polanisia dodecandra". Natural Resources Conservation Service PLANTS Database. USDA. Retrieved 9 October 2015.
- "Redwhisker clammyweed". www.fs.fed.us. Retrieved 2019-07-26.
- A. Scott Earle, James L. Reveal (2003). Lewis and Clark's green world: the expedition and its plants. Farcountry Press. ISBN 9781560372509.
- "Clammy-weed (Polanisia dodecandra)". Native Wildflowers of the North Dakota Grasslands. US Geological Survey: Northern Prairie Wildlife Research Center. 2006-03-08. Retrieved 2012-06-08.
- "PLANTS Profile: Polanisia dodecandra (L.) DC. redwhisker clammyweed". US Department of Agriculture Natural Resources Conservation Service. Retrieved 2012-06-08.
|This Brassicales article is a stub. You can help Wikipedia by expanding it.|