180 Rydberg: Notes on Fabaceae — I 



coriaceous, sessile, somewhat triquetrous, pointed, scarcely 

 longer than the calyx;" "flowers ochroleucous." In Watson's 

 plant the scape is three- to seven flowered, usually as long as, or 

 longer than, the leaves; the pod is decidedly flat; and the corolla 

 is purple. All the characters given by Nuttall fit A. exiliflcrus 

 A. Nelson, but I do not think that the two are identical. There 

 is, however, a plant of southern Wyoming and northern Colorado 

 that agrees fully with Nuttall 's type. This resembles Nelson's 

 species but is smaller and has shorter leaves. In this respect 

 it approaches H. br achy car pus, being distinguished from that 

 species by its narrower and more pungent leaves and by its 

 shorter, unmottled, and rather turgid pod, thicker nearer the 

 lower suture than the upper, hence Nuttall 's expression, "some- 

 what triquetrous.' 1 Nuttall 's specimen in the Gray Herbarium 

 has leaves only, so that Watson had no opportunity to compare 

 the pods. The following specimens belong to this species: — 



Wyoming: Rocky Mountains, Nuttall; Fremont; Ham's 

 Fork, C. C. Curtis ; Green River, Jones; Hanna, Payson & Payson 

 1694. 



Colorado: Canon City, Brandegee. 



4. Homalobus exilifolius (A. Nels.) Rydb. See notes 

 under tne preceding species. The following specimens belong 

 here : — 



Wyoming: Freezeout Hill, Elias Nelson 4493 ; Fort Steele, 

 Tweedy 4194. 



5. Homalobus lingulatus (Sheld.) Rydb. This is known 

 only from the original collection, and its description is much 

 like that of the preceding species, the only essential difference 

 being the glabrous calyx. The mature fruit is unknown. When 

 the plant is better understood it may prove to be the same as 

 H. exilifolius, in which case the species should bear Sheldon's 

 specific name, which antedates Nelson's by five years. 



6. Homalobus uniflorus Rydb. It is possible that this 

 may represent an aberrant form of H. br achy car pus, i.e. Astrag- 

 alus simplicifolius, as understood by Watson. * The pod, how- 

 ever, is different, being lanceolate in outline, more tapering at 

 the apex, 6-7 mm. long and 2-3 mm. wide. It is, therefore, 



