LEGUMINOS^E. (PULSE FAMILY.) 61 



§ 2. Pod ovate or glolmse, membranous, inflated, nearly glabrous, sessile, completely 

 2-ceiied and mure or less didymous by the intrusion of both sutures, many- 

 seeded. — Stipules distinct, adnate : flowers spicate. 



4. A. diphysus, Gray. Nearly glabrous throughout : leaflets 6 to 1 1 

 pairs, obovate or oblong : flowers blue or purple, occasionally white : pod 

 curved-acuminate, frequently mottled — S. \V. Colorado, southward, arid 

 westward in the Great Basiu. 



§ 3. Pod cartilaginous or coriaceous, sessile, oblong, turgid, terete, sulcate at both 

 sutures, at length incurved, completely 2-celled. — Subacaulescent, shining with 

 a soft silky-villous often yellow pubescence : peduncles long, scape-like : spikes 

 dense : flowers violet. 



5. A. mollissimus, Torr. Pod narrow-oblong, 5 to 9 lines long, gla- 

 brous, subdidymous: ovary also glabrous. — From Colorado to Nebraska and 

 W. Texas. 



6. A. Bigelovii, Gray. Pod oval-oblong, 6 lines long, densely woolly, but 

 slightly sulcate. — From S. W. Colorado to Texas and Mexico. 



§ 4. Pod coriaceous, turgid, oblong, terete, scarcely sulcate and only on the back, 

 nearly straight, sessile, completely 2-celled. — Tall, with appressed gray pu- 

 bescence or glabrate : spikes dense : flowers whitish, ochroleucous or purplish : 

 stipules distinct or united, free. 



7. A. Canadensis, L. Leaflets 10 to 14 pairs, elliptical or oblong, ob- 

 tuse : pod and ovary glabrous. — From Colorado to the head-waters of the 

 Columbia and Saskatchewan, and eastward to the Atlantic States. 



8. A. Mortoni, Nutt. Differs from the last in the somewhat pubescent, 

 ovary and pod, and the latter more decidedly sulcate dorsally and less crowded 

 in the matured spike, and the leaflets 6 to 8 pairs. — A. Canadensis, var. 

 Morloni, Watson. Head-waters of the Missouri and Platte, westward into 

 Utah, Nevada, and California. 



§ 5. Pod coriaceous, oblong or ovate, straight or slightly curved, usually more or 

 less compressed-triangular, dorsally sulcate (cross-section obcordate), completely 

 2-celled, pubescent. — Caulescent, grayish short-pubescent or glabrate : stipules 

 more or less sheathing. 



9. A. adsuxgens, Pall. Rather stout: spikes at length oblong or cylin- 

 drical : flowers purplish : pod sessile. — From Colorado to Oregon, Nebraska, 

 and the Saskatchewan. 



10. A. terminalis, Watson. Slender: leaves long-petiolate : raceme an 

 inch long, open, long-pedunculate : flowers nearly sessile, reftexed, purplish : 

 pod sessile, straight, erect. — Proc. Am. Acad. xvii. 370. S. Montana. 



11. A. hypoglottis, L. Slender : flowers capitate, violet: pod silky-vil- 

 lous, very shortly sti/n'tate. — From S. Colorado northward along the mountains 

 and Red River Valley to Alaska and the Arctic Circle. 



12. A. ventorum, Gray. Stems flexuous, 4 to 6 inches high, simple: 

 leaflets broadly obovate : raceme loose, short-peduncled, equalling the leaves . 

 flowers light yellow: pod sessile, slightly curved. — Watson in Am. Naturalist, 

 viii. 212. Wind River, Wyoming, Parry. 



