12a. Blade not more than 10 mm. wide 13 



12b. Blade usually much more than 10 mm. wide 15 



13a. Plants spreading by stolons 



72. Cynodon dactylon — Bermuda Grass 



Leaves rolled in bud-shoot; sheath round, smooth, hairy at throat, 

 split with hyaline margins; auricles absent; collar broad, hairy on mar- 

 gins; ligule a fringe of hairs, .4 to .6 mm. long, fused at base; blade 5 to 

 6 mm. wide, rough above, smooth near base and rough near tip below, 

 margins rough and hyaline. Inflorescence — 4 or 5 digitate spikes. Mary- 

 land south. Common in fields and grasslands. 



13b. Plants not spreading by stolons 14 



14a. Sheath margins hyaline 



73. Eragrostis cilianensis — Stinkgrass 



Leaves rolled in bud-shoot; sheath round to somewhat flattened, 

 smooth and occasionally hairy at throat, split with overlapping hyaline 

 margins; auricles absent; collar narrow to broad, hairy or hairy on mar- 

 gins; ligule a fringe of hairs, .4 to 1 mm. long; blade 5 to 10 mm. wide, 

 at least slightly rough above, glossy below and smooth at least near base, 

 margins at least somewhat rough. Inflorescence — an erect, rather con- 

 densed, dark gray-green to tawny panicle. Throughout. Cultivated 

 ground, fields and waste places. 



14b. Sheath margins hairy 



74. Setaria viridis — Green Foxtail 



Leaves rolled in bud-shoot; sheath round to somewhat flattened, 

 smooth, split with overlapping margins hairy; auricles absent; collar 

 broad, divided, hairy at least on margins; ligule a fringe of hairs, .8 to 1 

 mm. long; blade 5 to 10 mm. wide, rough above, smooth to slightly rough 

 and keeled below, margins rough and hyaline. Inflorescence — dense, 

 bristly, cylindrical, green or purplish, erect, spike-like. Common through- 

 out. Cultivated soil and waste places. 



15a. Plants with large creeping rhizomes 



75. Phragmites communis — Common Reed 



Leaves rolled in bud-shoot ; sheath round, smooth to somewhat rough 

 or sparsely short hairy or hairy at top, split with overlapping scarious 

 margins; auricles absent; collar narrow to broad, hairy at least on mar- 

 gins; ligule a fringe of hairs, .6 to 1 mm. long, usually with a few to 6 

 to 12 mm. long; blade 15 to as much as 50 mm. wide, smooth above and 

 below, margins smooth to rough. Inflorescence — a large, densely flow- 

 ered, tawny or purple panicle. South to Maryland. Mostly wet land and 

 marshes. 



26 



