146 THE FORAGE AND FIBER CROPS IN AMERICA 



Timothy, Phleum pratense L. 



Bitter dock, Rumex obtusifolia L. 



Curled dock, R. crispus L. 



Sheep sorrel, R. acetosella L. 



Fox tail grass, Chaetochloa verticillata (L.) Scribn. 



Yellow fox tail, Ch. glauca (L.) Scribn. 



Green fox tail, Ch. viridis (L.) Scribn. 



Ragweed, Ambrosia artemisiae folia L. 



Lamb's quarters, Chenopodium album L. 



Witch grass, Panicum copillare L. 



Crab-grass, P. sangninale L. 



Rough pigweed, Amaranthus retrofle.rus L. 



Tumbleweed, Am. graecisans L. 



Alsike clover, Trifolium hybridum L. 



White clover, T. repens L. 



Selfheal, Prunella vulgaris L. 



Along with these should be mentioned black medic and 

 Canada thistle, the latter being reported by the Canadian 

 Department of Agriculture to have been found in 23 per cent. 

 of 163 samples. 



152. Germination and Viability. Haberlandt gives the tem- 

 perature for the germination of red clover as follows: min- 

 imum 34, optimum 86, and maximum 99 F. With the 

 optimum temperature and moisture seeds will begin to sprout 

 vigorously in two to four days. The standard of germination 

 is 90 per cent. The Ohio Station found a range of 32 to 99 

 per cent, of germination in 28 samples of commercial seed. 1 

 The New York State Station found the highest germination 

 when the specific gravity was between 1.25 and 1.30, and less 

 when either above or below this specific gravity. 2 



The viability of clover seed has not been definitely deter- 

 mined, but with our present knowledge seed that is over three 

 years old must not be considered safe to sow. Beal found an 

 average germination of 36 per cent, in red clover seed that had 



Sta. Bui. No. 142 (1903). 

 2 New York State Sta. Bui. No. 256 (1904). 



