136 PASTORAL AND AGRICULTURAL BOTANY 



excelled in the temperate regions of North America. They are valuable 

 for summer pasture and winter pasture, and if used for the latter purpose 

 they should not be closely pastured during the summer months. Drought 

 inhibits the growth of Kentucky blue grass. 



Seeding. The number of seeds per pound varies from 2,185,000 to 

 3,888,000. Usually 40 pounds of commercial seed per acre is sown alone 

 when a good stand is desired. It is usually mixed with other seeds in the 

 formation of permanent pasture. The following is the usual composition 

 of such mixtures, costing about $3 to $4 per acre. 



Timothy 15 pounds 



Kentucky blue grass 10 pounds 



Meadow fescue 2 pounds 



Red clover 8 pounds 



White clover 2 pounds 



The grass seeds of such a mixture are sown in September and the clover 

 seeds, as early as possible in the spring. In the construction of lawns at 

 least 40 pounds of 50 per cent, viable seed of Kentucky blue grass should 

 be used alone or with white clover. In another formula for the making 

 of lawns, the bulk of the seed used is Kentucky blue grass mixed with 

 red-top and Rhode Island bent grass. The advantage of using several 

 kinds of grass is that the first comers hold possession of the ground, or act 

 as a nurse crop, until the stronger, but slower-growing, Kentucky blue 

 grass gets complete root hold when, in the struggle for life, the earlier 

 grasses are gradually excluded. Kentucky blue grass is considered one of 

 the most troublesome weeds in New Zealand. 



Redtop (Agrostis alba). This native grass of North America is perhaps 

 the third, or fourth most important perennial grass of our country. The 

 culms are a foot (3 dm.) to 3 feet (10 dm.) tall from a creeping or stolo- 

 niferous rootstock. The leaves are flat, stiff and upright to lax and 

 spreading. The panicle is contracted after flowering of a greenish, purple, 

 or brown color with its branches slightly roughish. The spikelet is one- 

 flowered. The lemmas nearly equal the glumes. They are 3-nerved, 

 rarely short awned. The palea are one-half to two-thirds as long as the 

 lemmas. 



The variety vulgaris is known as Herd's Grass in Pennsylvania. It 

 has shorter, more slender culms with smaller more branching panicles 

 and narrow leaves. The variety stoloniftra (not the A. stolonifera) is a 



