484 POACE^. 



or acute, obscurely 3-nerved, easily splitting, about 2.5 mm. long; 

 palea slightly incurved, spatiilate or narrowly obovate when not 

 spread open, truncate, erose or slightly 3-lobed, nerves very ob- 

 scure, smooth, 2-3.5 mm. long. Grain not seen. 

 Mexico (Chihuahua), Pringlc 415. 



14. E. sessilispicata Buckl. Proc. Acad. Phila. 97 (1862). 

 Diplachne rigida Benth. Vasey, Grasses U. S. 35 (1855). Eragros- 

 Us rigida Scribn. Proc. Acad. Phila. 304 (1891). 



Culms erect, slender, 30-50 cm. high. Blades of sterile shoots 

 scabrid, involute or flat, 3-15 cm. long, 2 mm. wide, those of the 

 culm 1-2 ; ligule a mere ring bearing thin hairs. Panicle much 

 exserted, simple, open, pyramidal, 12-20 cm. long; rays single, the 

 longest 6-8 cm. long, bearing about six appressed spikelets. Spike- 

 lets sessile, 6-9-flowered, 6-12 mm. long; empty glumes lanceolate, 

 subequal, 4-5 mm. long; first 1-nerved, second 3-nerved; floral 

 glume firm, lanceolate, 3-nerved, 4 mm. long; j)alea firm, incurved 

 or tumid at base, 3 mm. long. 



Texas, Reverchon for U. S. Dept. Agricul. 550, Curtiss 3453; 

 ]^ew Mexico, Wriglit 7G0. 



15. E. plumbea Scribn. ined. 



A tufted erect rather slender perennial, 40-60 cm. high. 

 Sheaths smooth; ligule bearded; blades flat or iuvolute-rigid, 

 smootli below, scabrid above, 8-12 cm. long, 3-5 mm. wide. Pan- 

 icle simple, ovate or pyramidal, 8-12 cm. long, rays single, bearded 

 in the axils, bearing a few short branches. S2)ikelets mostly pe- 

 dicellate, lead-colored, flattened, ovate-lanceolate or linear, 10-18- 

 flowered, 6-10 mm. long; empty glumes ovate-lanceolate, 1-nerved, 

 scabrid on the keel, first 2 mm. long, second 3 mm. long; floral 

 glume ovate-lanceolate, scabrid on the keel, lateral nerves less promi- 

 nent, 2.5-3 mm. long; palea slightly incurved, linear before spread- 

 ing, acute, keels scaberulous. Grain very slightly compressed, 

 ovoid, 1 mm. long. 



Mexico (Guadalajara), Pa?wer 240, Pringle 2311. 



16. E. Brownei (Kunth) Nees, Steud. Norn. Ed. 2. 1 : 562 

 (1841). Poa pulymoiyha R. Br. Prod. 1:180 (1810). Mega- 



