LEGUMINOS.E. (PULSE FAMILY.) 69 



* * Cushioned: flowers scarcely exserted from among the simple leaves: pod many- 



ovuled, margined with rather strong sutures. 



60. A. Simplicifolius, Gray. Leaves hoary with an appressed silky 

 pubescence, linear- or spatulate-lanceolate, crowding the extremities of the 

 usually short branches : scapes 2 to 3-flowered : flowers purple, the keel 

 strongly arched: pod half-included in the calyx, glabrous. Loc. cit. 231. 

 Sources of the Platte. W. Wyoming (Parry). 



* * * Caulescent, often depressed : flowers subsessile in the axils of the leaves : 



pods 3 to 4-ovuled, usually l-seeded, ovate, sessile : leaves pinnate, with few 

 leaflets 



61. A. Kentrophyta, Gray. Intricately branched from a long root, 

 broadly depressed-cespitose, hoary with a short silky pubescence : leaflets 2 to 

 3 pairs, linear-subulate, usually rigid and divaricate, pungent : flowers 1 to 3, 

 ochroleucous or tinged with violet : pods compressed, pubescent, acuminate, 

 somewhat incurved. Proc. Acad. Philad. 1863, 60. From Montana and 

 Wyoming to New Mexico and westward into Nevada. 



B. Leaves apparently palmately 3-foliolate. 



21. Pod conical-ovate, acuminate, not stipitate nor compressed, coriaceous, some- 

 ivhat included in the calyx, neither suture intruded. Perennial, cespitose from 

 a much-branched ivoody caudex, low, silvery-silky, with crowded leaves : leaflets 

 crowded. 



62. A. triphyllus, Pursh. Acaulescent, glossy silky: stipules glabrous: 

 primary leaves sometimes 5-foliolate with cuneate oblanceolate leaflets, the 

 rest with 3 longer lanceolate leaflets, long petioled, exceeding the sessile crowded 

 flowers : calyx-teeth half shorter than the tube : corolla ochroleucous or white : pod 

 villous, included. From Nebraska to the Saskatchewan. 



63. A. tridactylicus, Gray. Resembliug the last in habit and leaves, 

 but stipules villous, flowers pale purple, calyx-teeth equalling the tube, pod puberu- 

 lent, exposed by the falling away of the calyx. Proc. Am. Acad. vi. 527. Moun- 

 tains of Colorado. 



64. A. sericoleuCUS, Gray. Very broadly cespitose, silky-hoary: the 

 branches covered with villous stipules : leaves all 3-foliolate, not equalling the 2 

 to 6 flowered filiform peduncles; leaflets oblanceolate or cuneate-oblong : calyx- 

 teeth about equalling the tube : corolla purple : pod hoary, half included in the calyx. 



Am. Jour. Sci. n. xxxiii. 410. From the sand-hills of N. Colorado to 

 N. Nebraska. 



14. OXYTROPIS, DC. 



Like Astragalus, but distinguished by a subulate beak at the tip of the keel. 



Mostly low 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: naked scapes bearing a head or short spike of flowers. 

 Rev. Oxyt., Gray in Proc. Amer. Acad. xx. 



1. Stipules free from the petiole and from each other: leafy-stemmed or depau- 

 perate plants nearly stemless. 



1. O. deflexa, DC. Loosely soft-pubescent or silky : taller forms over a 

 foot high : leaflets crowded in 12 to 16 pairs, lanceolate to oblong, i to ^ inch 



