71 



the upper broadly obovate, shorter than the spikelet, three-nerved, 

 not keeled, scarious margined ; flowering glumes oblong, obtuse, 

 compressed, chartaceous ; palet narrow, hyaline. 



1. E. obtusata, Gr. Common. Pennsylvania to Oregon. 



2. E. Pennsylvanica, Gr. Common. New England to Montana. 

 E. Pennsylvanica, var. filiformis, Chap. Florida. 



E. Pennsylvanica, var. major, Vasey. New Mexico. 



Dissantheliitm, Trin. 



Spikelets two to four flowered, all fertile, in a narrow panicle ; 

 outer glumes herbaceous, narrow, and acute, keeled, the lower one- 

 nerved, the upper three-nerved, both much longer than the flowers; 

 flowering glumes ovate, obtuse or obtusish, obtusely keeled, three 

 to five nerved, the outer nerves near the margin, scarious at the tip, 

 pnbescent, especially on the marginal nerves and keel ; palet nar- 

 row, strongly two-keeled, nearly equalling its glume. 

 1. D. Californicum, Benth. (Stenochloa Californica, JVutt.) Cal- 

 ifornia. 



Catabrosa, Beauv. 



Spikelets two to three flowered, in a loose panicle ; outer glumes 

 hyaline-membranaceous, shorter than the flowers, the lower short 

 and narrow, the upper obovate, three-nerved, erosely dentate at the 

 apex; flowering glumes membranaceous, obtuse, prominently three- 

 nerved ; palet little shorter than its glume, prominently two-keeled. 

 An aquatic grass. 



1. C. aquatica, Beauv. Rocky Mountains and British America to 

 Alaska. 



Ekagbostis, Host. 



Spikelets several, usually mauy-flowered, pedicellate or sessile, in 

 a loose and spreading, or narrow and clustered, panicle, the rhachis 

 of the spikelet usually glabrous and articulate under the flowering 

 glumes, but often tardily so and sometimes inarticulate. Outer 

 empty glumes unequal and rather shorter than the flowering ones, 

 keeled, one-nerved ; flowering glumes obtuse or acute, unawned, 

 three-nerved, the keel prominent, the lateral nerves sometimes very 

 faint : palet shorter than the glume, with two prominent nerves or 

 keels, often persisting after the glume and grain have fallen away. 

 1. E. alba, Presl. New Mexico and Arizona. 



