5a. Ligule more than 1 mm. long 



5. Poa annua — Annual Bluegrass 



Leaves folded in bud-shoot; sheath distinctly flattened, smooth, gen- 

 erally split with overlapping margins; auricles absent; collar narrow to 

 medium broad, divided; ligule membranous, mostly 1 to 2 mm. long, 

 rounded to acute; blade 2 to 3 mm. wide, smooth above and below and 

 on margins, blade-tip boat-shaped. Inflorescence — a small, open, few- 

 branched panicle. Common throughout. Lawns, pastures, open ground 

 and waste places. 



5b. Ligule 1 mm. or less long 6 



6a. Blade 2 mm. or less wide 7 



6b. Blade more than 2 mm. wide 11 



7a. Blade rolled, very narrow (about .5 mm. wide), bristle-like 



6. Festuca capillata — Hair Fescue 



Leaves folded in bud-shoot; sheath flattened, smooth, split; auricles 

 absent; collar narrow, divided, indistinct; ligule membranous, .2 to .4 

 mm. long, truncate; blade bristle-like (about. 5 mm. wide), smooth. 

 Inflorescence — a very slender panicle. Throughout. Lawns and waste 

 places. 



7b. Blade not as above (1 mm. or more wide), may be bristle-like 8 



8a. Ligule a fringe of hairs 



7. Aristida oligantha — Prairie Three-awn Grass 



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

 with overlapping hyaline margins; auricles absent; collar narrow, di- 

 vided; ligule a fringe of hairs, about .2 mm. long; blade 1 to 2 mm. 

 wide, rough and sometimes sparsely long hairy above, smooth below, 

 margins rough. Inflorescence — a narrow, loosely flowered panicle. 

 Massachusetts south. Open dry ground. 



8b. Ligule membranous ' 



9a. Plants densely tufted, base of stems not usually decumbent ... 10 

 9b. Plants not densely tufted, base of stems usually decumbent 



8. Festuca rubra — Red Fescue 



Leaves folded in bud-shoot; sheath distinctly flattened, smooth or 

 very short hairy, split ; auricles absent ; collar mostly broad ; ligule mem- 

 branous, .2 to .3 mm. long, truncate; blade about 2 mm. wide, smooth 

 above and below, margins smooth or slightly rough. Inflorescence— a 

 narrow, contracted panicle. Common throughout. Lawns, meadows and 

 waste places. 



10 



