600 Rydberg : Rocky Mountain flora 



able. The generic name Vilfa is not available, for the type of 

 Vilfa Adans. is apparently a species of Agrostis. As there is no 

 character, whatever, to separate these plants from Muhlenbergia 

 as now limited, the only rational way to treat them at present is to 

 transfer them all to Muhlenbergia. At any rate, they are conge- 

 neric with M. WrigJitii Vasey, slender specimens of which are 

 very hard to distinguish from M. cuspidata here proposed. The 

 other Rocky Mountain species are : 



Muhlenbergia Richardsonis (Trin.) Rydb. 



Vilfa Richardsonis Trin. Mem. Acad. St. Petersb. VI. Nat. 5 2 : 



103. 1840. 

 ? Agrostis brevifolia Nutt. Gen. 1 : 44. 18 18. 



The specific name brevifolia may have to be taken up for this 

 species, but it is doubtful if Agrostis brevifolia is a synonym of this. 

 Professor Scribner claims that it belongs to the preceding species. 

 What Vilfa Richardsonis Trin. is, is not doubtful, and that specific 

 name is therefore preferable. 



Muhlenbergia simplex (Scribn.) Rydb. 



Sporobolus simplex Scribn. Bull. U. S. Div. Agrost. 11 : 48. 

 1898. 



Muhlenbergia filiformis (Thurber) Rydb. 



Vilfa depauperata filiformis Thurb. ; S. Wats. Bot. King's Expl. 

 376. 1871. 



Vilfa gracillima Thurb. Bot. Calif. 2: 268. 1880. Not Muh- 

 lenbergia gracillima Torr. 1856. 



Sporobolus filiformis Rydb. Contr. U. S. Nat. Herb. 3: 189. 

 1895. 



Muhlenbergia aristulata Rydb. 



Sporobolus aristatus Rydb. Bull. Torrey Club 28: 266. 190 1. 

 Not Muhlenbergia aristata Pers. 1805. 



Muhlenbergia Wolfii (Vasey) Rydb. 



Vilfa minima Vasey, Bot. Wheeler Surv. 282. 1878. Not V. 



mini in a Trin. 1855. 

 Sporobolus Wolf 'i Vasey, Bull. Torrey Club 10: 52. 1883. 





