This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
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.
Vesicaria didymocarpa Hook. Fl. Bor. Am. 1: 49. pl. 16.
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.