16 BULLETIN" 622, U. S. DEPAETMENT OF AGRICULTURE, 



KEY TO THE SUBVARIETIES. 



1. Horcleum vulgare pallidum Seringe (1841, p. 346). 



Outer glumes narrow. 

 Kernels white. 

 Awns rough. 



Spike narrow, lax, nodding typka. 



Spike wide, dense, the edges parallel ; awns not widely spread- 

 ing parallelum Kornicke (as var., 1882, p. 166). 



Spike wide, very dense,, pyramidal, awns widely spreading. 

 pyramidatum Kornicke (as var., 1882, p. 164). 

 Awns smooth. 



Spike narrow, lax, nodding. 



rikotense Regel (as var., 1908, p. 74). 

 Kernels bluish. 

 Awns rough. 



Spike narrow, lax, nodding. 



coerulescens Seringe (as var., 1841, p. 347). 

 Kernels purple. 

 Awns rough. 



Spike narrow, lax, nodding. 



subviolaceum Kornicke (as var., 1895, p. 9). 

 Outer glumes wide. 

 Kernels white. 

 Awns rough. 



Spike narrow, lax, nodding. 



latiglumatum Kornicke (as var., 1895, p. 9). 

 Spike wide, dense, erect. 



eurylepis, Kornicke (as var., 1882, p. 167). 



2. Hordeum vulgare nigrum Willdenow (as sp., 1809, p. 1037). 



Outer glumes narrow. 

 Awns rough. 



Spike narrow, lax, nodding typica. 



Spike wide, dense, erect. 



sehimperiamvm Kornicke (as var., 1882, p. 165). 

 Awns smooth. 



Spike narrow, lax, nodding. 



leiorrhynchum Kornicke (as var., 1882, p. 178). 

 Outer glumes wide. 

 Awns rough. 



Spike narrow, lax, nodding. 



atrospicatum Kornicke (as var., 1895, p. 9). 

 Spite wide, dense, erect platylepis Kornicke (as var., 1895, p. 9). 



3. Hordeum vulgare horsfordianum Wittmack (1884). 



Outer glumes narrow. 

 Kernels white. 



Spike narrow, lax, nodding typica. 



Spike wide, dense, erect. 



hexasticofurcatum K. H. in Beaven (as var., 1902, p. 577). 



4. Hordeum vulgare atrum Kornicke (1895, p. 9). 



Outer glumes narrow. 



Spike narrow, lax, nodding typica. 



Spike wide, dense, erect. 



densifurcatum K. H. in Beaven (as var., 1902, p. 577). 



