4b. Plant without creeping rhizomes 5 



5a. Blade smooth above and below 



230. Arrhenatherum elatius — Tall Oatgrass 



Leaves rolled in bud-shoot; sheath round, smooth or sometimes 

 sparsely short hairy, split with overlapping hyaline margins ; auricles ab- 

 sent; collar broad, divided; ligule membranous, 1 to 2.5 mm. long, trun- 

 cate, toothed; blade to 10 mm. wide, smooth above and below, margins 

 slightly rough. Inflorescence — a narrow, pale or purplish, shining pan- 

 icle. Throughout. Meadows, open ground and waste places. 



5b. Blade rough or short hairy on one or both surfaces 



231. Sphenopholis obtusata — Prairie Wedgegrass 



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

 lapping margins hyaline or sometimes hairy; auricles absent; collar nar- 

 row, may be divided; ligule membranous, 1 to 2 mm. long, truncate to 

 rounded, mostly toothed ; blade 3 to 8 mm. wide, slightly rough to rough 

 or short hairy above and below and on margins. Inflorescence — a dense, 

 erect, spike-like panicle. Throughout. Old fields and moist ground. 



GROUP 19 



la. Blade 4 mm. or less wide 2 



1 b. Blade more than 4 mm. wide 4 



2a. Plant with creeping rhizomes or stolons 3 



2b. Plant without rhizomes or stolons 



232. Agrostis perennans — Autumn Bent 



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

 ping hyaline margins ; auricles absent ; collar narrow to medium broad ; 

 ligule membranous, to 2 mm. long, rounded to acute; blade to 4 mm. 

 wide, rough above and below and on margins. Inflorescence— a. pale to 

 tawny, open panicle. Throughout. Open ground and old fields. 



3a. Ligule 2 to 3 mm. long 



233. Agrostis palustris — Creeping Bent 



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

 ping hyaline margins; auricles absent; collar narrow to broad; ligule 

 membranous, 1 to 3 mm. long, rounded to acute, may be toothed; blade 

 2 to 4 mm. wide, smooth to rough above and below and on margins. 

 Inflorescence — a narrow, dense, pale or purple panicle. Marshes along 

 coast. Also cultivated for putting greens. 



66 



