72 



AGROSTIDEAE 



advantage in its contest for a place; otherwise it would not be 

 there and a much more \alua1)lc i^rass would be the prevailing 

 one. 



Muhlcnhcrgia arcnicohi is similar to the last in the 

 appearance of the panicle l)ut it is usually a larger plant, often 

 12 to 15 inches high, and its leaves are longer and not 

 recurved. It also has a different habitat, being common at 

 lower le\'els on the sandy soils of the southern, especially 

 the southeastern part of the State. wh:ere it is an unimportant 

 member of the grass flora. 



26 MUHLENBERGIA Sohieh. 



Plant stout, 3 feet high or more; panicles from 

 10 inches to over 1 foot long, with very 

 numerous spikelets. 

 Spikelets with a long awn. 

 Spikelets without any awns. 

 Plants lower, 2 feet high or less, more slender, 

 the i)anicle always shorter. 

 Panicle narrow ard spike-like. 

 Low annual, 3 to 6 inches high. 



Plants perennial, mostly larger but some 

 species low. 



Kmpty glun:es awl-shai)ed; leafy bianch- 

 ed plants with long rootstocks covered 

 with (overlapping scale.«. 

 Empty glumes about as long as the 



flowering glumes, not awned. 

 Empty glumes longer llian the flowering 

 glumes, awned. 

 Flowering glumes .slightly villous. 

 Flowen'ng glumes long white villous. 

 Empty glun.es broader, lanceolote to 

 ovate. 



•.wrlc-'s or ve: y short 



Flf we- i- g !?'.iri.C's 

 awned. 



En.pty glun es less iban lialf as long 



as the flowering glumes. 

 Empty giUmes moie llian half as long 

 u.s' tn«? fiowering glun.e ■. 

 lln.pty glumes awn-pointed, flower- 

 irg glumes scabrous or smooth. 

 i'anicle deni-t, obture, .".-10 mm. 

 wide. 



laniclo slender, lax, tapering at 

 the apex, less than .5 mm wide. ' 

 Empty glumes acute, not avvn- 

 lii'inf.'fl. 



.1/. vaseyana. 



^f. (listifhophyUa. 



M. schaffneri. 



A. M. inexicana. 



M. racemosa. 

 M. CO mat a. 



ricliardsonis. 



.li . irrifjhtii. 



riispithttfl. 



