time of full bloom, which in the latitude of Washington, D.C., is 

 about the ist of May. In England the average yield ranges from 

 i^ to 2^ tons per acre, and the hay is better and more nutritious 

 than that of red clover. Eighty pounds of seed should be sown per 

 acre, any time from the middle of May to the end of June, and, 

 unlike alfalfa, it should be covered quite deeply to insure germin- 

 ation. If shelled seed is to be had, half as much will suffice. Fresh 



FIG. 23. Prickly pear (Opuntia engelmanni), 



seed must always be used, as it loses its vitality if kept a year. It 

 can be grown in any part of the United States, and should be more 

 extensively cultivated, especially in localities where the ground is 

 too dry or too barren for red clover. The yield of seed ranges 

 from 10 to 25 bushels of 40 pounds. Sainfoin should not be 

 pastured closely, as it does not have the same recuperative ability 

 as the clovers. 



Opuntia engdmanni (Nopal ; prickly pear. Fig. 23). A species 



of cactus which grows wild from western Texas through the arid 



regions of the south-west to California. Its so-called leaves, or flat 



oints of the stem, are sometimes, in large specimens, a foot long 



