BULLETIN 461, U. S. DEPARTMENT OF AGEICULTUEE. 



BB. Sheaths laterally compressed. 

 C. Collar and sheath not hairy. 



D. Rootstocks or stolons present. 



E. Creeping stems (rootstocks) more than one-eighth inch in 

 diameter. 



31. Johnson grass (Andropogon halepensis) . 

 EE. Creeping stems (stolons) less than one-eighth inch in 



diameter. 



32. Nimble Will (MvMeribergia schreberi). 

 DD. Rootstocks and stolons not present. 



E. Liguie wanting. 



33. Barnyard grass (Echinocliloa crus-gaUi). 

 EE. Liguie present. 



P. Liguie membranous. 



34. Sudan grass {Andropogon sorghum 



sudanensis ) . 

 PP. Liguie a fringe of hairs. 

 G. Blades hairy above. 



35. Yellow foxtail (Cliaetochloa lutescens). 

 GG. Blades not hairy. 



36. Spreading witch - grass (Panicum di- 



clwtomiflorum) . 

 CC. Collar or sheath hairy (either or both). 

 D. Liguie membranous. 



E. Sheaths white, with pink nerves. 

 F. Liguie entire, hairy on the back. 



37. Rescue grass (Bromus unioloid.es). 

 PP. Liguie toothed on margin, not hairy on the back. 



38. Velvet grass (Holcus lanatus). 

 EE. Sheaths pale, without pink nerves. 



F. Stolons present. 

 G. Sheaths hairy. 



39. Crab-grass (Synthcrisma sanguinalis). 

 GG. Sheaths not hairy. 



40. Small crab-grass (Syntherisma ischae- 



muin). 

 PP. Stolons not present. 



G. Habit of growth low and decumbent at the base. 



41. Field paspalum (Paspalum laeve). 

 GG. Habit of growth upright. 



42. Smooth paspalum (Paspalum dilatation). 

 ■ DD. Liguie a fringe of hairs. 



E. Rootstocks present. 



43. Bermuda grass (Capriola dactylon). 

 EE. Rootstocks not present. 



P. Sheaths hairy. 



G. Collar hairy on the back. 



44. False redtop (Tridens flams). 

 GG. Collar not hairy on the back. 



45. Green foxtail (Chaetochloa viridis). 



