Rydberg: Notes on Fabaceae — I 181 



more like that of the true //. simplicifolius* The following 

 specimens may be cited : — 



Wyoming: Evanston, A. Nelson 2QJI (flower); Carter, M. 

 E. Jones (fruit). 



B. Tenelli 



7. Homalobus tenellus (Pursh) Britton. The description 

 of Astragalus tenellus Pursh, dating from 18 14, was drawn 

 (according to Pursh himself) from flowering specimens of the 

 present species and the fruit of some other Astragalus, both of 

 which had been collected by Lewis. When Pursh found that 

 his description had been based on a mixture, he redescribed the 

 flowering specimens, associating them with a fruiting plant 

 collected by Bradbury on the Upper Missouri and giving the 

 species the new name Ervum multiflorum , on account of its 

 Ervum-Yike pods. A fragment of Bradbury 's plant in the Torrey 

 Herbarium is clearly identical with the flowering specimens 

 collected by Lewis: hence there is no doubt that Astragalus 

 tenellus (so far as the flowering specimens are concerned) and 

 Ervum multiflorum are the same. 



8. Homalobus dispar Nutt. Nuttall first described this 

 species in 1818 under the name Orobus dispar, from specimens 

 that he collected at Fort Mandan. To those who consider H. 

 dispar and H. tenellus identical, this note will be of no interest. 

 It is here presented, however, for the benefit of those who are 

 willing to admit their distinctness as species or varieties. Since 

 Nuttall and Bradbury were members of the same expedition 

 and often collected together, one might perhaps assume that 

 Orobus dispar and Ervum multiflorum were the same. They are 

 not. Nuttall 's specimen in the Torrey Herbarium agrees with 

 his description in having broader leaflets than H. tenellus and 

 broader short-stipitate pods. Of Phaca nigrescens Hook., 

 which was described in 1830 from specimens collected by 

 Richardson, there is likewise a duplicate in the Torrey Herbar- 

 ium. This belongs to H. dispar, while a specimen collected by 

 Nuttall on the Platte River, which was named Homalobus 

 nigrescens by him and Astragalus multiflorus by Hooker, is 

 like A . tenellus Pursh. Macbride states correctly that " Nuttall's 



* See also Bull. Torrey Club 34: 49. 1917. 



