G62 Rydberg : Astragalus and its segregates 



Xylophacos vespertinus (Sheld.) Rydb. 



Astragalus vespertinus Sheld. Bull. Geol, & Nat. Hist. Surv. Minn. 

 9 : 150. 1894. 



Xylophacos amphioxus (A. Gray) Rydb. 



Astragalus amphioxus A. Gray, Proc. Am. Acad. 13 : 366. 1878, 



m 



Xylophacos uintensis (Jones) Rydb. 



Astragalus uintensis Jones, Proc. Calif. Acad. II. 5: 670. 



1895. 



Xylophacos pygmaetis (Nutt.) Rydb. 



Phaca pygmaca Nutt. ; T. & G. Fl. N. Am. I : 349. 1838. 

 Astragalus chaniacluce K, Gray, Bot. Ives' Rep. 10. 1861. 

 Astragalus Cicadae Jones, Zoe 4:35. 1893. 



This is somewhat aberrant from the typical species of Xylo- 

 phacos^ as its pod is spongy at maturity. 



Xylophacos Parryi (A. Gray) Rydb. 



Astragalus Parryi A. Gray, Am. Jour. Scl. II. 33 : 409. 1862. 



Also somewhat aberrent on account of its long pod inflexed 

 on both sutures, and in this respect approaching the genus Holco- 

 phacos. 



Xylophacos Purshil (Dougl.) Rydb. 



Astragalus PurshiiY)o\xg\.] Hook, Fl. Bor. Am. I : 152. 183 1. 



Torrey, Gray, Watson and Sheldon placed this species and its 

 allies in the subgenus Phaca, while Astragalus Shortianus and its 

 closer relatives were placed in Astragalus proper. There is only 

 one character to separate the two groups, viz., the long woolly 

 pubescence on the pods in one and the sparse and usually ap- 

 pressed pubescence in the other. Some of the A. Purshii relatives 

 have the sutures just as much inflexed as any of the other group. 

 The habit, calyx, etc., are practically the same in both. 



Xylophacos Newberryi (A. Gray) Rydb. 



Astragalus Nezvberryi A. Gray, Proc. Am. Acad, 12 : 55. 1876. 



W 



Watson placed this in the subgenus Phaca, in the same section 

 as A. FendUri, A. Hallii and A. Jlexuosus. Scarcely a worse 

 place could have been chosen. The structure of the pod and its 

 pubescence associate it with the preceding and its allies, while 

 the habit is more like a dwarf form of the A. Shortianus group. 



