GRASSES AND FORAGE-PLANTS. 



117 



the pulse-family, or Leguminosae, which includes the larger portion 

 of forage-plants called "artificial grasses," in distinction from the 

 Gramineae, the only true, and often called the "natural," grasses. 

 The generic name trefoil, or trifolium, is derived from the Latin 

 " tres" (three) and "folium" (a leaf) ; and the genus can be very 

 readily distinguished by the number and arrangement of its leaves in 

 three leaflets, and flowers in dense oblong or globular heads. 



The stems of red clover are ascending, somewhat hairy ; leaflets oval 

 or obovate, often notched at the end, and marked on the upper side 

 with a pale spot ; heads ovate, and set directly upon the stalk, instead 

 of upon branches. This species is regarded as by far the most im- 

 portant of the whole genus for the practical purposes of agriculture. 

 It has passed into a number of varieties, one of which is biennial, 

 another perennial ; the latter by long cultivation 

 becoming biennial, while the former, as is true 

 of most biennial and many annual plants, as- 

 sumes, to some extent, the character of a peren- 

 nial, and can be made to last three or four 

 years, or even more, by simply preventing it 

 from running to seed. The introduction of 

 clover into England, it is often said, produced 

 an entire revolution in her agriculture ; and, 

 indeed, when we consider how important a part 

 it plays in our system of farming, we can with 

 difficulty imagine how our ancestors ever got 

 on at all in farming without it. Be this as it 

 may, it is certain that it led to many of the 

 most important improvements in the rotation of crops. Clover is 

 very properly regarded as a fertilizer of the soil. The action of 

 its long and powerful tap-roots is not only mechanical, loosening 

 the soil, and admitting the air, but also chemical, serving to fix 

 the gases important to enrich the earth ; and when these roots 

 decay, they add largely to that black mass of matter we call soil. Jt 

 serves also, by its luxuriant foliage, to destroy annual weeds which 

 would spring up on newly-seeded land, especially after imperfect cul- 

 tivation. But one of the most valuable uses of it, and one too often 

 overlooked, is to shade the surface of the soil, and thereby increase 

 its fertility. 



Another great advantage in favor of the cultivation of clover con- 

 sists in its rapid growth. But a few months elapse from the sowing 



RED CLOVER. 



