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..
Shrubs, perennial herbs, or in tropical regions trees, with odd-pinnate leaves and white yellow or violet flowers in terminal racemes or panicles. Calyx generally campanulate, its teeth short. Standard obovate or orbicular, erect or spreading; wings obliquely oblong; keel oblong, nearly straight. Stamens all distinct or very nearly so; anthers versatile, all alike; style incurved. Ovary short-stalked; ovules ∞. Pod stalked in the calyx, coriaceous or fleshy, terete, constricted between the subglobose seeds, mainly indehiscent. [Arabic, yellow.]
About 25 species, natives of warm and tropical regions. Besides the following, about 5 others occur in the southern States. Type species: Sophora alopecuroides L.
Sophora sericea Nutt. Gen. 1: 280. 1818.
Herbaceous, woody at the base, erect or ascending, branched, silky or silvery pubescent with appressed hairs, 6'-12' high. Stipules subulate, deciduous; leaves short-petioled; leaflets 7-25, short-stalked, obovate or elliptic, obtuse or emarginate at the apex, narrowed or cuneate at the base, 3"-6" long; raceme peduncled, rather loosely flowered, 2'-4' long; flowers white, about 8" long, nearly sessile; pod dry, coriaceous, 1'-2' long, about 2" thick, pubescent, few-seeded.
Plains and prairies, South Dakota, Nebraska and Wyoming to Texas, Arizona and Mexico. April-June.