5a. Blade green except for a conspicuously white midrib 



189. Sorghum halepense — Johnson Grass 



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

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

 broad, sometimes divided, may be hairy ; ligule membranous, 3 to 6 mm. 

 long, rounded, ciliate; blade 20 to 35 mm. wide, smooth above and below 

 at least near base, midrib white above and prominent below, margins 

 generally rough and hyaline. Inflorescence — a large, loose, erect panicle. 

 Massachusetts south. Open ground, fields and waste places. 



5b. Blade not as above 6 



6a. Blade green 



190. Phalaris arundinacea — Reed Canarygrass 



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

 ping hyaline margins; auricles absent; collar narrow to broad, may be 

 divided; ligule membranous, 3 to 7 mm. long, rounded to acute, occa- 

 sionally toothed, may be hairy on back; blade 10 to 20 mm. wide (occa- 

 sionally to 30 mm. ) , smooth to slightly rough and rarely hairy near base 

 above, keeled and smooth to rough below, margins usually rough and 

 rarely short hairy near base. Inflorescence — a densely flowered, spread- 

 ing to narrow panicle. Throughout. Marshes, rivers banks and moist 

 places. 



6b. Blade striped with white 



191. Phalaris arundinacea var. picta — Ribbon Grass 



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

 ping hyaline margins; auricles absent; collar medium broad, divided; 

 ligule membranous, 2 to 4 mm. long, rounded; blade to 12 mm. wide, 

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

 Inflorescence — a densely flowered, spreading to narrow panicle. Grown 

 for ornament. 



7a. Plants glaucous 



192. Calamagrostis cinnoides — Reedgrass 



Leaves rolled in bud-shoot; sheath round, smooth or slightly rough at 

 top, split with overlapping hyaline margins; auricles absent; collar nar- 

 row to medium broad, may be divided; ligule membranous, 3 to 6 mm. 

 long, rounded, generally toothed; blade 8 to 15 mm. wide, rough above, 

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

 contracted panicle with short, erect branches. Throughout. Bogs and 

 moist ground. 



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