116 MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



Figure 190— Poa trivialis Panicle, X 1; floret, X 10. (Coville, N.Y.) 



3. Palustres. — Perennials without creeping rhizomes; lemmas webbed 

 at base, glabrous, or pubes- 

 cent on the nerves. 

 22. Poa trivialis L. Rough 



bluegrass. (Fig. 190.) Culms 



erect from a decumbent base, 



often rather lax, scabrous below 



the panicle, 30 to 100 cm tall; 



sheaths retrorsely scabrous or 



scaberulous, at least toward the 



summit; ligule 4 to 6 mm long; 



blades scabrous, 2 to 4 mm wide; 



panicle oblong, 6 to 15 mm long, 



Figure 191.— Distribution of 

 Poa trivialis. 



the lower branches about 5 in a 

 whorl; spikelets usually 2- or 3- 

 flowered, about 3 mm long; lemma 

 2.5 to 3 mm long, glabrous except 

 the slightly pubescent keel, the 

 web at base conspicuous, the 

 nerves prominent. % — Moist 

 places, Newfoundland and On- 

 tario to Virginia, West Virginia, 

 Michigan, South Dakota, and on 

 the Pacific coast from southern 

 Alaska to northern California; on figure 192.— Poa mardda. Panicle, x 1; floret, x 10. 

 ballast, Louisiana (fig. 1 9 1 ) ; intro- (Type) 



duced from Europe. Sometimes used in mixtures for meadows and 

 npastures der the name rough-stalkedn meadow grass. 



