19a. Collar not hairy 



121. Panicum dichotomiflorum — Fall Panicum 



Leaves rolled in bud-shoot ; sheath round, smooth, split with overlap- 

 ping hyaline margins; auricles absent; collar broad; ligule a fringe of 

 hairs, 2 to 3 mm. long, mostly fused at base; blade 15 to 20 mm. wide, 

 mostly smooth above but sometimes slightly rough near tip or sparsely 

 hairy near base, smooth and glossy below, margins smooth to rough. 

 Inflorescence — widely spreading terminal and axillary panicles. Common 

 throughout. Cultivated fields, moist ground and waste places. 



19b. Collar hairy 



122. Setaria faberii — Giant Foxtail 



Leaves rolled in bud-shoot ; sheath round, smooth, split with overlap- 

 ping hyaline margins; auricles absent; collar broad, may be divided, 

 hairy; ligule a fringe of hairs, 1.5 to 3 mm. long; blade 15 to 25 mm. wide, 

 rough above, smooth near base and rough near tip below, margins rough 

 and hyaline. Inflorescence — dense, bristly, cylindrical, nodding, spike- 

 like. New York south. Common. Waste and cultivated ground. 



GROUP 9 



la. Sheath rolled in bud-shoot 3 



lb. Sheath folded in bud-shoot 2 



1/ 



2a. Auricles present 



123. Lolium perenne — Perennial Ryegrass 



Leaves folded in bud-shoot ; sheath distinctly flattened to almost round, 

 smooth, closed to near top; auricles small; collar narrow; ligule mem- 

 branous, to 2 mm. long, rounded, toothed ; blade to 6 mm. wide, smooth 

 above and below, glossy and keeled below, margins slightly rough. In- 

 florescence — a long, narrow, flat spike with unawned spikelets placed 

 edge to rachis. Cultivated throughout. 



2b. Auricles absent 



124. Glyceria striata — Fowl Mannagrass 



Leaves folded in bud-shoot; sheath round to distinctly flattened, 

 smooth to slightly rough, closed to near top ; auricles absent ; collar me- 

 dium broad to broad, may be divided ; ligule membranous, generally 2 to 

 5 mm. long but may be shorter, rounded to acute ; blade 4 to 8 mm. wide, 

 smooth above and below at least near base, margins smooth to rough, tip 

 boat-shaped. Inflorescence — an open, nodding panicle. Throughout. 

 Moist meadows and wet places. 



3a. Ligule more than 3 mm. long 4 



38 



