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Native Wildflowers of the North Dakota Grasslands

JPG -- species photo

Clammy-weed (Polanisia dodecandra)


All but extreme northern and northeastern North Dakota is home to clammy-weed. Plants are found from Quebec and Maryland to southern Saskatchewan and Manitoba south to Arkansas and northern Mexico at elevations under 6,000 feet. Plants have been introduced elsewhere.

Clammy-weed is a sticky, hairy, annual (reproduce from seed each year) with simple stems and a strong, rank odor. North Dakota specimens are usually less than a foot tall, but plants from further south may reach nearly three feet. Leaves are about two inches long and bear three leaflets about an inch long. About 20 flowers are clustered at the top of the plant. Flowers are about a half inch long, white with purple bases, and produce numerous stamens that overtop the petals. Fruits consist of slender capsules about one or two inches long that are filled with many tiny, dark seeds.

Look for clammy-weed in late June to early July in sandy native prairie. I could find no information on the effects of grazing on this species, nor any mention of possible economic uses.

This species is a member of the caper family (Capparaceae), named after similarly pungent capers, the edible flower-buds of a Mediterranean plant, Capparis spinosa. This is a relatively small family of about 900 species, mostly tropical, that contains many trees and shrubs. The generic name was compounded from the Greek polys "many," and anisos "unequal," ways in which the genus differs in stamen characters from another genus in the family. There are about 30 species in this widely-distributed genus. The specific epithet dodecandra means "having twelve stamens" in botanical Latin. Clammy weed was first described for science by the great Swedish naturalist Carl von Linne (Linnaeus), the father of modern plant taxonomy, in his famous Species Plantarum of 1753.


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