22. Physaria didymocarpa (Hooker) A. Gray, Gen. Amer. Bor. 1: 162. 1848.
Vesicaria didymocarpa Hooker, Fl. Bor.-Amer. 1: 49, plate 16. 1830; Coulterina didymocarpa (Hooker) Kuntze
Perennials; caudex branched, (cespitose); densely pubescent, trichomes (often stalked, appressed to wavy and spreading), several-rayed, rays furcate or simple, (slightly to strongly umbonate, nearly smooth to strongly tuberculate). Stems several from base, decumbent, (unbranched, leafy for the genus), ca. 1 dm. Basal leaves (forming a strong rosette; long-petiolate); blade obovate, 1.5-4(-8) cm, (base ± abruptly narrowing to petiole), margins usually repand or dentate, rarely entire, (apex usually angular, surfaces silvery). Cauline leaves: blade oblanceolate, 1-2 cm (width 4-8 mm), margins entire or with occasional tooth, (apex acute). Racemes congested, (elongated in fruit, greatly exceeding leaves). Fruiting pedicels (spreading, straight or slightly curved), 8-12 mm. Flowers: sepals lanceolate to oblong, 6-8 mm, (often keeled); petals spatulate, 10-12 mm. Fruits (erect), didymous, inflated, 10-20 × 10-20 mm, (papery or firm, basal sinus shallow to deep, sometimes barely notched, apical sinus deep, narrow, usually closed); valves (retaining seeds after dehiscence), loosely pubescent, trichomes spreading (appearing fuzzy; replum obovate to broadly oblong, not constricted, 3-4 mm, as wide as or wider than fruit, apex obtuse; ovules (4-)8 per ovary; style 7-9 mm. Seeds flattened.
Subspecies 3 (3 in the flora): w North America.