8b. Widest blades more than 20 mm. wide 



108. Phragmites communis — Common Reed 



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

 lapping scarious margins; auricles absent; collar broad; ligule a fringe 

 of hairs, to 1.2 mm. long, mostly with a few hairs to 6 mm. or more 

 long; blade 20 mm. or more wide, smooth above and below, margins 

 slightly rough. Inflorescence — a large, densely flowered, tawny or purple 

 panicle. South to Maryland. Mostly wet land and marshes. 



9a. Blade long hairy near base above 



109. Setaria lutescens — Yellow Foxtail 



Leaves rolled in bud-shoot ; sheath distinctly flattened, keeled, smooth, 

 split with overlapping hyaline margins; auricles absent; collar broad, 

 may be divided or hairy on margins; ligule a fringe of hairs, 1 to 1.8 mm. 

 long, may be fused at base; blade 7 to 12 mm. wide, long hairy near base 

 above, smooth below at least near base, margins at least slightly rough 

 and hyaline. Inflorescence — dense, bristly, cylindrical, yellow, erect, 

 spike-like. Common throughout. Cultivated soil and waste places. 



9b. Blade rough above 10 



10a. Margins of collar hairy 



110. Cenchrus pauciflorus — Field Sandbur 



Leaves rolled in bud-shoot; sheath distinctly flattened, smooth, split 

 with overlapping margins hyaline; auricles absent; collar broad, hairy 

 on margins; ligule a fringe of hairs, 1 to 1.4 mm. long; blade to 6 mm. 

 wide, rough above, keeled and smooth near base but rough near tip be- 

 low, margins rough and hyaline. Inflorescence — a nearly round, hairy 

 bur with sharp spines. Throughout. Sandy, open ground. 



10b. Margins of collar not hairy 



111. Setaria verticillata — Bristly Foxtail 



Leaves rolled in bud-shoot ; sheat h distinctly flattened, keeled, smooth, 

 split with overlapping hyaline margins; auricles absent; collar medium 

 broad, divided; ligule a fringe of hairs, 1 to 1.6 mm. long, fused at base; 

 blade 5 to 10 mm. wide, rough above, smooth below, margins rough and 

 hyaline. Inflorescence — dense, bristly, cylindrical, erect, spike-like, with 

 barbed bristles. Massachusetts south. Cultivated soil and waste places. 



1 la. Blade 5 to 6 mm. wide 



112. Danthonia sericea — Downy Oatgrass 



Leaves folded in bud-shoot; sheath round, long hairy, split with over- 

 lapping margins; auricles absent; collar broad, hairy; ligule a fringe of 

 hairs, .8 to 1.2 mm. long; blade 5 to 6 mm. wide, smooth above, long 

 hairy below, margins long hairy. Inflorescence — a narrow panicle with 

 stiff, short branches bearing 2 to 6 spikelets. Massachusetts south. Chiefly 

 Coastal Plain. Sand barrens. 



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