8 THE FORAGE AND FIBER CROPS IN AMERICA 



of the leaf blade may, therefore, be removed without injuring 

 the growing part. 



6. Variations. While possessing certain characters in com- 

 mon, the different species of grasses not only vary widely from 

 each other in habits of growth and minor botanical characters, 

 but different individuals of the same species also vary widely ; 

 although less advantage has been taken of this fact to produce 

 strains or varieties than in the case of the cereals. (53) 

 (C. A. 37) Grasses vary in the depth of their root growth, 

 smooth brome grass being deep-rooted and able to withstand 

 drought; while Kentucky blue grass is shallow-rooted and 

 liable to injury during dry weather, which makes them adapted 

 to different portions of the United States. 



The strongly stoloniferous habit of Kentucky blue grass, red- 

 top, and brome grass causes them to produce dense, even sod; 

 while orchard grass grows in bunches and does not make an 

 even sod. Timothy is somewhat variable in its stoloniferous 

 habit, not only producing a less dense sod, but making its 

 duration less certain. (50) In some cases the culms arc 

 erect, some decumbent, others are decumbent at the base only, 

 while still others are kneed. The proportion of basal leaves 

 to culm leaves, as well as the height of culm and its proportion 

 as compared with the leaves, influences the yield and the 

 quality of the hay. 



Certain characters serve to distinguish the grasses when not 

 in flower. These are the size ancl thickness of the leaf blade, 

 size and shape of the ligule, and the color of the basal leaf 

 sheath. When in flower, the inflorescence is of course the 

 chief method of distinguishing species. The inflorescence may 

 be spike-like as in the case of timothy and meadow foxtail, or 

 a panicle as in the case of redtop and Kentucky blue grass. 

 Grasses are further distinguished by the number of flowers to 

 a spikelet, the relative lengths of outer glumes, flowering glume, 



