HOW TO KNOW THE GRASSES 



2b. Sheaths smooth or nearly so; rhizomes short and thick, densely 



covered with scales: lower panicle branches borne singly. Fig. 278. 



WHITE GRASS Leersia virginica WUld. 



Figure 278 



Perennial; culms 50 — 120 cm. tall, weak 

 and slender; panicle 10 — 20 cm. long, with a 

 few simple branches, the spikelets lying close- 

 ly parallel to them. Some of the smaller 

 panicles may be hidden in the sheaths. Leaf 

 blades yellowish green. Damp woods and 

 thickets; mud flats. July — October. 



TRIBE X. ZIZANIEAE 



la. Plants growing immersed in water, the upper leaves 1 — 5 mm. 

 wide, floating on the water surface. Fig. 279. 



WATER GRASS Hydrochloa carolinensis Beauv. 



Perennial; culms slender, weak, up to 1 

 m. long, floating in water, the upper leaves 

 on the surface. The staminate spikelets are 

 borne at the tips of branches and the pistil- 

 late ones in the axils of leaves. Neither type 

 has evident glumes, and both have only a 

 single floret. Ponds and slow streams. Fur- 

 nishes some feed for livestock. Blooming ap- 

 parently rarely. June — August. 



Figure 279 



147 



