Low perennial stellate-canescent herbs, with erect or ascending usually quite simple stems, spatulate mostly entire leaves, the basal ones tufted, and medium-sized yellow flowers in terminal racemes. Petals longer than the sepals. Style filiform. Silicles membranous, stellate-pubescent, their cells inflated, the septum narrow. Seeds not margined; cotyledons accumbent. [Greek, bellows, from the resemblance of the inflated fruit.]

About 6 species, natives of western North America, the following typical.

6 Physaria A Gray Gen 1ll 1 162 1848 361

1. Physaria Didymocàrpa (Hook.) A. Gray. Double Bladder-Pod

Fig. 2019

Vesicaria didymocarpa Hook. Fl. Bor. Am. 1: 49. pl. 16.

1830. Physaria didymocarpa A. Gray, Gen. 1ll. 1: 162. 1848. Physaria brassicoides Rydb. Bull. Torr. Club 29: 237.

1902.

Densely stellate-canescent, pale green; root long and deep. Stems decumbent or ascending, slender, simple, 3'-12' long; leaves spatulate, the basal ones obtuse, entire, or few-lobed, narrowed into margined petioles, 1'-5' long; stem-leaves nearly sessile, acute or subacute, much smaller; racemes 2'-5' long in fruit; flowers 5"-6" broad; pods didymous, variable, often 6" thick through the strongly inflated cavities, emarginate at base and summit or narrowed at base, commonly broader than high; seeds numerous.

In dry soil. North Dakota to Saskatchewan, British Columbia, Nebraska, Colorado and Nevada. May-Aug.