AVENE.E. 359 



a. Florets deciduous, empty glumes persistent. . . . (c) 

 c. Awn of floral glume on the back. . . » . , . (d) 



d. Spikelets 1 cm. or less long » . (e) 



e. Flowers all perfect or the upper ones stami- 



nate or neuter (i) 



i. Floral glume obtuse or denticulate. . . (k) 

 k. Awns taper-pointed, not articulate. . 7G 

 k. Awns cylindrical, articulate near the 



middle,, apex clavate 75 



i. Floral glume 2-toothed, lower floret 



awned 77 



e. Florets 3, the lower one staminate and 

 strongly awned, the upper one perfect and 



more or less awned 79 



d. Spikelets more than 10 mm. long. . . . . 78 

 c. Awn of floral glume between 2 teeth or lobes. . . (m) 

 m. Spikelets 2-flowered, the upper one perfect or 

 pistillate, the lower staminate, spikelets in 



threes. , 80 



m. Spikelets 3- to several-flowered, all jDcrfect or 



the upper imperfect 81 



73. (157). HOLCUS L. Sp. PI. 1047 (1753). 

 Spikelets deciduous as a whole, 2-flowered, numerous and 

 crowded in an open panicle, the lower flower perfect, the upper 

 staminate; rachilla articulate above the outer glumes. Empty 

 glumes 2, nearly equal, conduplicate, acute, the second broader, 3- 

 nerved, acute or extended into an awn ; floral glume shorter, mem- 

 branous, the lower awnless, the upper with a short dorsal bent 

 awn; palea 2-keeled. Stamens 3. Styles distinct. Grain oblong, 

 included but not adherent. 



Soft annual or perennial grasses, with blades flat or rarely con- 

 duplicate. 



Sp3cies 8, found in Europe, Africa, and one or more spread by 

 the agency of man. 



The genus Holcus was made by Linnreus and continued by 

 Robert Brown to include species now separated and placed in Sor- 



