Plant of the Week
Redwhisker clammyweed (Polanisia dodecandra)
By Charlie McDonald
Redwhisker clammyweed is in the caper family (Capparaceae). This family derives its name from the Mediterranean plant, Capparis spinosa, that is the source of the edible pickled flower buds known as capers. The caper family has nine genera in the United States with the best known being spiderflower (Cleome). The clammyweeds and spiderflowers are closely related and often confused. In the clammyweeds, the ripening seed pods project upward; in the spiderflowers, the ripening seed pods project outward or hang down. Redwhisker clammyweed has three subspecies. The one shown in these photographs is sometimes called large-flowered clammyweed (subspecies trachysperma) because it has larger petals and much longer stamens than the other two subspecies. The name clammyweed comes from the sticky or clammy residue left on the hands after handling the plant. Redwhisker refers to the clusters of long red stamens.
Redwhisker clammyweed grows almost throughout the United States in full sun, mesic to dry conditions, and barren sandy or gravelly soils. This includes such places as sand or gravel bars along rivers, dry sandy prairies, gravelly areas along roadsides or railroads, and barren waste areas. It adapts well to highly disturbed areas where there is little other ground vegetation.
Redwhisker clammyweed is an easy-to-grow annual that makes a nice airy filler plant in gardens. It is grown from seed sown directly into the garden. It grows in a variety of soils, self-sows freely, and has excellent drought tolerance. However, seeds are not readily available from commercial sources. You may have to collect your own or trade with other native gardening enthusiasts.