438 
BOTAOT. 
the tu"be; banner whitish, veined; keol iuflexcil, with a narrow produced apex; pod oblong-linear 
curv-ed, pubescent, obcompressed-triangular, dorsal suture intruded, the ventral prominent and cari- 
nate. — Kew Mexico and Arizona. 
38. A. Oreganus, Nutt. Dwarf, hirsutish-canescent ; stipules scarcely isheatliing ; leaflets obovate, 
emarginate ; flowers ochroleucous (?), spicate-capitate upon a short peduncle, rather large ; calyx-tube 
cylindric, twice longer than the teeth ; ovai y septate nearly to the middle ; pod not known.— Rockv 
Mts., (Nuttall.) 
§ 13. MICROLOBI. Pod 2-3" long, sessile, coriaceous or cartilaginous, 6-7-ovuled, elliptic-ovate, 
either nearly terete and scarcely flattened on the back or broadly concave, always wholly 1-cellod, 
the ventral suture thick and prominent. Perennial, subcinereous ; stems erect or ascending, 
slender, rather rigid, 1° high or more ; leaflets 5-8 pairs, linear ; lower stipules somewhat united, 
the rest distinct ; racemes spikelike, many-flowered, virgate ; flowers small, purple, recurved- 
spreading ; calyx and teeth short.— Missouri and Nebraska to the Eocky Mts. 
39. A. GRACILIS, Nutt. Stems virgate ; leaflets nearly filiform, 7-10" long, obtuse or retuse ; racemes 
dense, elongated, long-peduncled ; flowers 3" long, pale-purple or whitish ; pods spreading, coriaceous, 
strongly concave on the back, white-hairy, at length glabrous, transversely rugose-veined, the ventral 
suture subacute, 
40. A. MICROLOBUS, Gray. Stems diftuse; leaflets 4-6" long, linear or oblong-Hnear, emarginate ; 
racemes rather short and usually loosely-flowered ; flowers deep-purple, 4" long ; pods reflexed, thick- 
cartiliiginous, puberuleut, finely rugnlose, turgid, a little flattened on the back, the ventral suture very 
thick. 
^ 14. OROBOIDEI. Pod stipitate or sessile, coriaceous or nearly membranous, scarcely or not at all 
obcompressed, 1-celled or imperfectly 2-celled, with the dorsal suture more or less deeply impressed 
or indexed. Caulescent, slender, glabrous or pubescent ; stipules nearly free, distinct except the 
lowest ; flowers in short often spikelike racemes, or few in small heads, rather small or middle- 
sized, purple to white, spreading ; calyx short. 
* Northern, perennial, ascending ; flowers pedicelled, mostly racemed; pods oblong, stipitate, (stipe 
very short in A. oroboides and simrsiflorus,) subsecund, usually pendent, the ventral suture rather ' 
prominent. 
(a.) Pod membranous, glabrous or finely puberuleut, slightly more compressed laterally, 1-celled with 
a very narrow rudimentary septum from the straight dorsal suture, the ventral suture gibbous. 
(1.) Pod long-stipitate, not sulcate, cross-section oval; leaflets never retuse, the lowest pair approxi- 
mate to the stipules except in the lower leaves ; flowers in a close raceme, white or bluish, keel 
violet. ' 
41. A. AiJouiGixcjr, Rich. Puberulent or subvillous ; pod semi-elliptic. See page 70. 
42. A. GLAijRiuscuLus, Gray. Glabrous or with short scattered hairs; leaflets thinner, green, liuear- 
lanceolato and subacute, or oblong and obtuse at both ends ; ovary glabrous ; pod lanceolate-sub'falcate, 
attenuate into a stipe 2-3 times exceeding the calyx ; otherwise hke the last, of which it is "probably 
only a variety."— Rocky Mts. of British America and Colorado. 
(2.) Pod short-stipitate, not dorsally sulcate or very obsoletely so, (the cross-section obovate, retuse,) 
minutely diukij^li-pubcscent ; leaflets subretuse ; flowers white, 4" long. ' 
43. A. RoBBixsii, Gray. Subgla1)rons ; stems 1° high, suberect ; leaflets 3-5 pairs, oval or oblono- • 
raceme close, oblong ; cal> x-tr, tU imu U shorter than the tube ; pods thin-membranous, oblong, straight 
or somewhat incurved, G" long, very obtuse and abruptly narrowed at base into an included stipe.— Ver- 
mont. S.'f pnge 70. 
(/>.) Pod more corinceons. black- or rarely cinereous-pubescent, more or less triangular and semi- 
■J-ccUrd, tlu' diu>;il suture sulcati'-iin]iressfd. 
(1.) Pod s<miewhat symmetrical, short, oblong b.ns-shap.Ml. .liglitly compressed, cross-section obcor- 
date, the ventral suture a little the more gibbous. 
44. A. OROBOU>E.s Ilorucm., Var. Americaxl'S, Gray. Subcinereous-puberulent ; stems suberect 
1-U high ; leallcts .VT pairs, oblong and oval or often linear-oblong, scarcely retuse; flowers 3-4" lonsr' 
in a long secund raccnu., violet or purple, the wings exceeding the keel ; pod 5-6" long 3-4 times loneer 
than the calyx, the apinv^sed pubescence usually ^ray, moderately sulcate, few-seeded; stipe verv 
short. — Labrador, on the Saskatchewan, and in the Rocky Mts. to Colorado. 
(2.) Pod triangular, more in.iuvss. .1. che cross-section deeply obcordate, rather straight or incurved 
gibbous on the back. Leaves souictiuies retuse or subemarginate. ' 
45. A. ALPixus, L. Hairy-pubescent or glabrous, diffuse; llaflets 6-12 pairs, oval or oblong; ra- 
