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..
Perennial herbs with tufted decumbent or ascending leafy stems, odd-pinnate leaves with numerous entire leaflets, the stipules distinct and nearly free from the petiole, and rather large white, yellowish, violet or purplish flowers in peduncled axillary racemes. Calyx campanulate or nearly cylindric, its teeth nearly equal. Standard rather narrow, erect, notched, longer than the wings; keel shorter than the wings; stamens diadelphous, the anthers all alike. Ovary sessile; ovules numerous. Pod globose to conic-fusiform, fleshy, becoming spongy, indehiscent, completely 2-celled. [Greek, earth-plum.]
Pod glabrous, globose, or oval.
Corolla purple; pod pointed.
Corolla yellowish-white; pod obtuse.
Pod pubescent, ovoid or oblong.
Pod ovoid, about 6" long, not wrinkled.
Pod oblong, curved, 1' long or more, wrinkled.
Astragalus crassicarpus Nutt. Fraser's Cat. 1813. Astragalus carnosus Pursh, Fl. Am. Sept. 740. In part. 1814. A. caryocarpus Ker, Bot. Reg. 2: pl. 176. 1816. G. crassicarpum Rydb. in Small, Fl. SE. U. S. 616.
Appressed-pubescent, branching at the base, branches decumbent or ascending, 6'-15' long, mostly simple. Stipules ovate, acute, 2"-3" long; leaflets 15-25, oblong, elliptic or sometimes obo-vate, obtuse, narrowed at the base, 3"-6" long, 1 1/2"-2 1/2" wide; peduncles equalling or shorter than the leaves; flowers violet-purple, 8"-9" long, in short racemes; pods thick, glabrous, globose or oval, short-pointed. 8"-12" in diameter.
Astragalus mexicanus A. DC. Pl. Rar. Jard.
Gen. 4:16. 1826. Astragalus trichocalyx Nutt.; T. & G. Fl. N.
A. 1 .332. 1838. G. mexicanum Rydb. in Small, Fl. SE. U. S.
Similar to the preceding species, but less pubescent and with the hairs somewhat spreading. Leaflets 17-33, oblong to obovate, obtuse or emarginate at the apex, narrowed at the base; flowers yellowish-white, or purplish at the tip, 9" 12" long, in short racemes; pod thick, glabrous, globose, not pointed, 1'-1 1/4' in diameter.
Prairies, Illinois to Nebraska, Kansas, Louisiana and Texas. Fruit edible. May.
Astragalus plattensis Nutt.; T. & G. Fl. N. A. 1:
332. 1838. G. plattense Rydb. in Small, Fl. SE. U. S. 616. 1903.
Villous-pubescent with spreading hairs, prostrate or ascending, 6'-2' high or long. Leaflets 13-29, oblong to obovate, obtuse at the apex, narrowed at the base, 4"-9" long, about 2" wide; stipules broad, ovate, pointed, 3"-4" long; flowers yellowish-white or tipped with purple, about 9" long, in short heads; pod ovoid, pointed, smooth, loosely pubescent, nearly straight.
Prairies, Indiana to Minnesota and Nebraska, south to Alabama and Texas. May.
Astragalus tennesseensis A. Gray; Chapm. Fl. S.
Stems erect or ascending from a deep root; plant villous with long whitish hairs. Leaflets 15-31, oblong, or linear-oblong, obtuse, or emarginate, nearly glabrous above, 6"-10" long, 2"-4" wide; stipules lanceolate, oval, or ovate-lanceolate; peduncles about equalling the leaves; racemes short, several-many-flowered; flowers about 10" long; pod oblong, conic, fleshy, 1' long or rather more, strongly wrinkled, at least when dry, its summit strongly curved.
On hillsides, Illinois to Tennessee, Alabama and Missouri. March-May.