2. Spikelets about 4 mm. long, loosely imbricate and usually pendulous and pec- 



tinately arranged at an angle to the branches of the panicle (3) 



3(2). Panicles 10-20 cm. long, open, the branches diverging 2. L. oryzoides. 



3. Panicles 5-10 cm. long, narrow, the branches ascending or appressed 



3. L. hexandra. 



1. Leersia lenticularis Michx. Catchfly grass. Fig. 133. 



Perennial with short scaly rhizomes (these seldom present on prepared speci- 

 mens); aerial culms 7-15 dm. long, 1-3 mm. thick, erect or often sprawling and 

 distally ascending; ligule a tough scale about 0.5 mm. long; blades 13-40 cm, long, 

 1-2 cm. broad, flat; panicle 1-2 dm. long, very open and subpyramidal, often 

 nodding, the branches naked about half their length; florets 4-5 mm. long, nearly 

 or quite as broad as long, sparsely pubescent, the keels comb-toothed. 



Sloughs, bayous, ditches, swamps and in mud and shallow water, and marshy 

 prairies in Okla. (Waterfall) and e. and s.e. Tex., infrequent or locally abundant, 

 late summer-fall; Md. to Minn., s. to the Gulf States. 



2. Leersia oryzoides (L.) Sw. Rice cutgrass. Fig. 134. 



Perennial with short slender scaly rhizomes; culms 7-15 dm. long, 2-3 mm. 

 thick, often decumbent and rooting at the lower nodes or erect, shortly bearded 

 at the nodes; ligule a firm scale about 0.5 mm. long; blades (3-) 7-25 cm. long, 

 6-11 mm. broad, flat; panicle 1-2 dm. long, open, the branches diverging, naked 

 for less than half their length; florets 3.7-5.5 mm. long, about 2.5 times as long 

 as broad, pubescent, the keels comb-toothed. 



Near and along creeks, in marshes, swamps, muddy borders of ponds, ditches 

 and rivers, often forming dense zones, in Okla. (McCurtain, Ottawa and Stephens 

 COS.) and in e. and n.-cen. Tex.. Edwards Plateau, n.w. part of Rio Grande Plains 

 and Plains Country, and Ariz. (Navajo Co.). infrequent, mostly spring-fall; most 

 of U. S. n. to Que. and B. C. (not known from Mont., Wyo., Nev. or Mex.) 



The seeds and rootstocks of this species are a favorite food of various ducks, 

 marsh birds and shore birds. 



3. Leersia hexandira Sw. Fig. 135. 



Perennial with short slender scaly rhizomes; culms 5-10 dm. long, 1.5-3 mm. 

 thick, usually long-decumbent and rooting at the lower nodes, shordy bearded at 

 the nodes; ligule a firm scale about 0.5 mm. long; blades 5-18 cm. long, 3-7 (-10) 

 mm. broad, flat; panicle 5-9 (-12) cm. long, 1-2 cm. broad, the few branches 

 acending or appressed, naked for less than half their length; florets 3.3-4.5 mm. 

 long, about 2.5 times as long as broad, sparsely pubescent, the keels minutely 

 comb-toothed. 



Near creeks, in shallow water of ditches and wet places, and in rivers and 

 resacas in e. and s.e. Tex. and coastal parts of the Rio Grande Plains, infrequent, 

 spring-fall; widely distributed in warmer parts of the world, in Am. n. to. Va. and 

 the Gulf States. 



4. Leersia virginica Willd. White grass. Fig. 135. 



Perennial with short rhizomes 2-4 mm. thick (these seldom present on pre- 

 pared specimens); culms 25-120 cm. long, 1-1.5 mm. thick, often geniculate and 

 rooting at a few of the lower nodes but mostly ascending or erect, upper nodes 

 minutely bearded; ligule a scale about 1 mm. long; blades 4-10 (-13) cm. long, 

 3-8 mm. broad, flat; panicle 5-10 (-18) cm. long, the very few branches diverg- 

 ing, naked for more than half their length; florets 2.5-3 mm. long closely ap- 

 pressed and parallel to the branches, 2 to 3 times as long as broad, microscopically 

 pubescent on sides and keels. 



274 



