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..
Astragalus melanocarpus Nutt. Fraser's Cat. Name only. 1813.
Astragalus missouriensis Nutt. Gen. 2: 99. 1818.
Densely silky-canescent all over, tufted, branching from the base, 2-5' long. Stipules ovate-lanceolate, acute, 2"-4" long, leaflets 7-21, elliptic or obovate, obtuse but sometimes mucronate at the apex, narrowed or rounded at the base, 3"-5" long; flowers few, violet-purple, s"-9" long in loose heads or short spikes; pod I-celled, sessile, acute, oblong, pubescent, dehiscent, coriaceous, circular in section, slightly keeled along the ventral suture, transversely wrinkled, about 1' long.
Plains, Kansas and Nebraska to Saskatchewan and New Mexico. May-July.
Astragalus Shortianus Nutt.; T. & G. Fl. N. A. 1: 331. 1838.
Silvery canescent, nearly acaulescent, somewhat branched from the base. Stipules ovate, acutish, about 2" long; leaflets 9-15, elliptic or obovate, acutish at the apex, narrowed or rounded at the base, 5"-9" long; flowers blue or violet, 7"-9" long; peduncles commonly shorter than the leaves; pod I-celled, sessile, coriaceous, 8-shaped in section, dehiscent at maturity, lanceolate-ovoid, puberulent, transversely wrinkled, strongly curved and beaked at the summit, 1'-1 1/2' long.
Plains and hills, North Dakota to Montana. Nebraska, Colorado, New Mexico and Arizona. May-July.
Glabrous or nearly so, decumbent or nearly erect, slender, somewhat branched, 10'-20' high. Stipules ovate, acute, about 2" long; flowers bluish or purple, 3"-4" long, in elongated spike-like racemes; leaflets 9-17, oblong or linear-oblong, 8"-10" long; pedicels at length 1" long; pod sessile, ellipsoid, I-celled, pendent, slightly inflated, obtuse at each end, apiculate, black-pubescent all over, 2"-3" long.
Labrador, Quebec and northern Maine; Saskatchewan to Yukon and Colorado. June-Aug.
28. 1823. Phaca aborigina Hook. Fl. Bor. Am. 1: 143.pl. 56. 1830. Homalobus aboriginum Rydb. in Britton, Man. 554. 1901.
Finely canescent or glabrate, erect, somewhat branched, 8-15' high. Stipules ovate, acute, membranous or foliaceous, 2" - 3" long; leaflets 9-13, linear or oblong, obtuse or acute, 6"-10" long; flowers white, tinged with violet, 4"-5" long, in rather loose racemes; peduncles longer than the leaves; pod slightly inflated, compressed, oval in section, I-celled, glabrous, half-elliptic, long-stipitate, acute at each end, slightly sulcate, the dorsal suture slightly intruded; calyx blackish-pubescent, its teeth subulate.