Bladder-vetch - Sphaerophysa salsula
Red Bladder-vetch, Alkali Swainsonpea
Rhizomatous herb. Stems single or clustered, erect, 40–90 cm. Herbage short-strigose. Leaves petiolate, stipulate, odd-pinnate with 15 to 25 elliptic leaflets 5–15 mm long. Inflorescence loosely-flowered, axillary racemes 5–18 cm long. Flowers papilionaceous; brick red, fading to brown; calyx white-strigose; sepals deltoid, ca. 1 mm long; banner 10–14 mm long, erect, ca. as long as the wings and keel; stamens 9 united, 1 separate. Fruit a papery, inflated, ovoid legume, 15–25 mm long (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)
Low elevation, mesic sites, often where disturbed; road edges, ditches, alkaline wetlands.