41 



flowering glume bears an awn two or three times as long as itself. 

 It is found in dry, open, or rocky woods and fence corners. In 

 agricultural value it corresponds to that species. 



28. M. Texana, Thurb. Texas to Arizona. 



29. M. virescens, Trin. New Mexico and Arizona. 



30. M. Willdenovii, Trin. Mow England to Arkansas. 



31. M. Wrightii, Yasey. Colorado to Arizona. 

 M. Wrightii, var. annulata, Yasey. Arizona. 



Brachyelytrum, Beauv. 



Spikelets one-flowered and with a sterile rudiment, appressed, in 

 a simple racemose panicle ; outer glumes minute, unequal, the upper 

 and larger about half a line long, persistent ; flowering glume char- 

 taceous, rigid, produced at the apex into an awn 8 to 10 lines long ; 

 palet hyaline, two-keeled, bifid at the apex. The rudiment (contin- 

 uation of the rhachilla) is bristle-like, half as long as the palet, and 

 partly lodged in the groove on its back. 

 1. B. aristatum, Beauv. Common. 



Lycukus, H. B. K. 



Spikelets one-flowered, single on the short branches of the spike- 

 like panicle, both the outer and the flowering glumes awned ; outer 

 glumes small, membranaceous, the upper, one awned, and the lower, 

 two or three awned, the awns longer than the flower; flowering 

 glume and palet of. thicker texture (as in Muhlenbergia.) There 

 are sterile spikelets intermixed with the fertile ones. 

 1. L. phleoides, H. B. K. 



Heleochloa, Host. 



Spikelets one-flowered, perfect, crowded in a spike or spike-like 

 panicle, which is partly included in the bract-like sheath of the 

 upper leaf. Outer glumes membranaceous, acute, complicate, cari- 

 nate, not awned ; flowering glume similar, keel thickish and herba- 

 ceous; palet rather shorter, compressed, two-nerved or two-keeled. 



1. H. alopecuroides. Host. (Crypsis, Lam) Introduced on ballast. 



2. H. schcenoidcs, Host. (Crypsis, Lam.) Introduced on ballast. 



Phleum, Linn. 

 Spikelets one-flowered, in small clusters, crowded into a dense 



