Northern Prairie Wildlife Research Center
Sometimes called "twinpod," double bladderpod has so far been collected only in Billings, McKenzie, and Slope counties in North Dakota. Elsewhere, plants can be found from western South Dakota and Wyoming to northeastern Washington and southwestern Alberta.
Double bladderpod is perennial (blooms every year) from heavy roots and a branched rootcrown (caudex). Seldom over 6 inches tall and with many branches, plants have a tufted appearance and are silvery-colored because of numerous short hairs. Plants have many basal leaves about 1-3 inches long arranged in a rosette-like pattern. The numerous yellow flowers are about 1/2 inch long atop slender pedicels. Silicles (seed pods) are about 1/2 inch long, inflated, and formed in pairs.
Look for this plant in late May on barren clayey, sandy, or rocky soils. I doubt that grazing pressure, unless severe, would have much effect on the abundance of this plant. I could find no information on any economic uses for double bladderpod. However, one source mentions that Amerindians use another species of Physaria for an emetic.
Double bladderpod is a member of the mustard family (Brassicaceae), some of whose over 2,500 members have been developed into food plants such as cauliflower, radish, and turnip, as well as many ornamentals. However, other mustards are notorious weeds. The family was named from brassica, the Latin name of cabbage. The generic name was derived from the Greek physa, "a pair of bellows." The specific epithet means "like brassica" in botanical Latin. The renowned Swedish botanist Per Axel Rydberg (1860-1931) described double bladderpod for science in 1902.