20 



BULLETIN 461, U. S. DEPARTMENT OF AGRICULTURE. 



28. Timothy {Phieum pratense; fig. 32). 



A stout, glabrous, tufted perennial ; leaves rolled in the bud ; collar broad, 

 continuous ; auricles none ; ligule membranous, short, obtuse, the apex 

 usually with several large teeth ; sheaths not compressed ; blades fiat, indis- 

 tinctly nerved, rough on the margins, one-fourth inch wide, sharp pointed. 



The thickened base, or " corm," of the old stem usually may be found attached above 

 the young plant below ground. 



29. Tall oat-grass (Arrhenatherum elatius; fig. 33). 



A loosely tufted perennial ; leaves rolled in the bud ; collar broad, divided 

 into two parts by a space, glabrous ; auricles none ; ligule membranous, 

 medium long, obtuse, finely toothed at apex, hairy on the back, sheaths not 

 compressed, usually glabrous, sometimes sparsely hairy, prominently nerved ; 

 blades flat, linear, one-half inch or more wide, sharp pointed ; nerves in 

 pairs, not prominent, separated by white lines as seen by transmitted light. 



30. Bulbous oat-grass (Arrhenatherum ela- 

 tius bulboswm ; fig. 34). 

 A loosely tufted perennial ; leaves 

 rolled in the bud ; collar broad, glabrous, 

 divided into two parts by a gap ; auricles 

 none ; ligule membranous, medium long, 

 obtuse, finely toothed at apex, hairy. on 

 the back ; sheaths not compressed, usually 



Fig 



35. - — Johnson grass 

 pogon halepensis). 



(Andro- 



Fig 



-Nimble Will (Muhleribergia 

 schreberi) . 



glabrous, sometimes sparsely hairy, prominently nerved ; blades flat, linear, 



one-fourth inch or more wide, sharp pointed ; nerves in pairs, separated by 



white lines when viewed by transmitted light. 



There is a chain of from two to five bulbous growths at the base of the stems below 



ground which distinguishes this grass from tall oat-grass. Bulbous oat-grass has been 



recently introduced into this country and is occasionally found in eastern Virginia and 



North Carolina. 



31. Johnson grass (Andropogon halepensis; fig. 35). 



A nearly glabrous perennial, creeping by rootstocks ; leaves rolled in the 

 bud ; collar broad ; auricles none ; ligule membranous, long, obtuse, lacerate 

 ciliate at top ; sheaths compressed, glabrous, usually pale, the outer ones 

 sometimes reddish brown ; blades fiat, narrowed at base, and hairy at the 

 very base, one-half inch or more wide, sharp pointed ; midnerve white, very 

 thick; rootstocks one-fourth inch or more in diameter. 



