12. A. distórtus, Torr. & Gray. Low, diffuse, many-stemmed, subglabrous; leaflets 17–25, oblong, emarginate; flowers in a short spike, pale-purple; pod ovate- or lance-oblong, curved, 6–9´´ long, glabrous, thick-coriaceous, somewhat grooved on the back, the ventral suture nearly flat.—Ill. to Iowa, Mo., Ark. and Tex.
13. A. lotiflòrus, Hook. Hoary or cinereous with appressed hairs; stems very short; leaflets 7–13, lance-oblong; flowers yellowish, in few-flowered heads, with peduncles exceeding the leaves or very short; calyx campanulate, the subulate teeth exceeding the tube; pod oblong-ovate, 9–12´´ long, acuminate, acute at base, canescent, the back more or less impressed, the acute ventral suture nearly straight.—Sask. to Neb. and Tex., west to the mountains.
14. A. Missouriénsis, Nutt. Short-caulescent, hoary with a closely appressed silky pubescence; leaflets 5–15, oblong, elliptic or obovate; flowers few, capitate or spicate, 5–8´´ long, violet; calyx oblong, the teeth very slender; pod oblong (1´ long), acute, obtuse at base, pubescent, nearly straight, obcompressed or obcompressed-triangular, depressed on the back and the ventral suture more or less prominent, transversely rugulose.—Sask. to Neb. and N. Mex.
II. Pod 1-celled, neither suture being inflexed or the ventral more intruded than the dorsal.—Phaca.
15. A. Coòperi, Gray. Nearly smooth, erect (1–2° high); leaflets 11–21, elliptical or oblong, somewhat retuse, minutely hoary beneath; flowers white, rather numerous in a short spike; calyx dark-pubescent; pod coriaceous, inflated, ovate-globose (6–9´´ long), acute, glabrous, slightly sulcate on both sides, cavity webby.—Ont. and western N. Y. to Minn. and Iowa.
16. A. flexuòsus, Dougl. Ashy-puberulent, ascending (1–2° high); leaflets 11–21, mostly narrow; flowers small, in loose racemes; pod thin-coriaceous, cylindric (8–11´´ long, 2´´ broad), pointed, straight or curved, puberulent, very shortly stipitate.—Red River Valley, Minn., to Col.
22. OXÝTROPIS, DC.
Keel tipped with a sharp projecting point or appendage; otherwise as in Astragalus. Pod often more or less 2-celled by the intrusion of the ventral suture.—Our species are low, nearly acaulescent perennials, with tufts of numerous very short stems from a hard and thick root or rootstock, covered with scaly adnate stipules; pinnate leaves of many leaflets; peduncles scape-like, bearing a head or short spike of flowers. (Name from ὀξύς, sharp, and τρόπις, keel.)
[*] Leaves simply pinnate.
1. O. campéstris, DC., var. cærùlea, Koch. Pubescent or smoothish; leaflets lanceolate or oblong; flowers violet or blue, sometimes pure white; pods ovate or oblong-lanceolate, of a thin or papery texture.—N. Maine to Labrador.