MANUAL OF THE GRASSES OF THE UNITED STATES 



537 



1. Oryza sativa L. Rice. (Fig. 1131.) Annual, or in tropical 

 regions sometimes perennial; culms erect, 1 to 2 m tall; blades elon- 

 gate; panicle rather dense, drooping, 15 to 40 cm long; spikelets 7 to 

 10 mm long, 3 to 4 mm wide; lemma and palea papillose-roughened 

 and with scattered appressed hairs, the lemma from mucronate to 

 long-awned. o — Cultivated in all warm countries at low altitudes 

 where there is sufficient moisture; one of the world's most important 

 food plants; sometimes adventive near the coast from Virginia to 

 Florida and Texas. 



112. LEERSIA Swartz 



(Homalocenchrus Mieg.) 



Spikelets 1-flowered, strongly compressed laterally, disarticulating 

 from the pedicel; glumes wanting; lemma chartaceous, broad, oblong 



to oval, boat-shaped, usually 5-nerved, 

 the lateral pair of nerves close to the 

 margins, these and the keel often 

 hispid-ciliate, the intermediate nerves 

 sometimes faint; palea as long as the 

 lemma, much narrower, usually 3- 

 nerved, the keel 

 usually hispid- 

 ~p& ciliate, the 

 lateral nerves 

 close to the 

 margins, the 

 margins firmly 

 held by the 

 margins of the 



lemma; stamens 6 or fewer. Peren- 

 nials, usually with creeping rhizomes, 

 flat, scabrous blades, and mostly 

 open panicles. Type species, Leersia 

 oryzoides. Named for J. D. Leers. 



Spikelets broadly oval, 3 to 4 mm wide 1. L. lenticularis. 



Spikelets elliptic, not more than 2 mm wide. 



Panicle narrow, the branches ascending or appressed 4. L. hexandra. 



Panicle open, the capillary branches finally spreading. 



Spikelets glabrous, about 2 mm long; culms tufted, erect; rhizomes wanting. 



5. L. MONANDRA. 



Spikelets hispidulous; culms decumbent at base; rhizomes present. 

 Lower panicle branches solitary; spikelets 3 mm long, 1 mm wide. 



3. L. VIRGINICA. 



Lower panicle branches fascicled; spikelets 5 mm long, 1.5 to 2 mm wide. 



2. L. ORYZOIDES. 



1. Leersia lenticularis Michx. Catchfly grass. (Fig. 1132.) 

 Culms straggling, 1 to 1.5 m tall, with creeping scaly rhizomes ; sheaths 

 scabrous at least toward the summit; blades lax, 1 to 2 cm wide; 

 panicle open, drooping, 10 to 20 cm long, the branches ascending or 

 spreading, naked below, branched above, branchlets bearing closely 

 imbricate spikelets along one side; spikelets pale, broadly oval, very 

 flat, 4 to 5 mm long, sparsely hispidulous, the keels bristly ciliate. 

 % — Ditches and swamps, Indiana to Minnesota, south to South 

 Carolina, Florida, and Texas (fig. 1133). 



Figure 1133.— Distribution of 

 Leersia lenticularis. 



Figure 1132. — Leersia lenticularis, X 1. 

 (McDonald 68, 111.) 



