662 RyDBERG: ASTRAGALUS AND ITS SEGREGATES 
Xylophacos vespertinus (Sheld.) Rydb. 
Astragalus vespertinus Sheld. Bull. Geol. & Nat. Hist. Surv. Minn. 
g: 150. 1894. 
Xylophacos amphioxus (A. Gray) Rydb. 
Astragalus amphioxus A. Gray, Proc. Am. Acad. 13: 366. 1878. 
Xylophacos uintensis (Jones) Rydb. 
Astragalus uintensis Jones, Proc. Calif. Acad. II. 5: 670. 
1895. 
Xylophacos pygmaeus (Nutt.) Rydb. 
Phaca pygmaea Nutt. ; T. & G. FL. N. Am. 1:349. 1838. 
Astragalus chamaeluce A, Gray, Bot. Ives’ Rep. 10. 1861. 
Astragalus Cicadae Jones, Zoe 4: 35. 1893. 
This is somewhat aberrent 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. Sci. II. 33: 409. 1862. 
Also somewhat aberrent on account of its long pod inflexed 
on both sutures, and in this respect approaching the genus /olco- 
phacos. 
Xylophacos Purshii (Dougl.) Rydb. 
Astragalus Purshit Dougl.; Hook. Fl. Bor. Am. 1: 152. 1831. 
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 4. 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 Newberryi A. Gray, Proc. Am. Acad. 12: 55. i 1876. 
Watson placed this in the subgenus Phaca, in the same section 
as A. Fendleri, A. Hallii and A. flexuosus. 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. 
