62 



region. It produces stout, deep-growing roots, and has many other 

 qualities commending it to the attention of the experimenter. Like 

 the preceding, it is most widely distributed on the west side of the 

 Continental Divide. 



The other clovers mentioned in the preceding list are all rather small 

 and are of especial value only as i)asturage. The most important are: 

 Parry's clover, generally distributed in the central Kocky Mountain 

 region, and most abundant at an altitude of from 10,000 to 13,000 feet; 

 silky dwarf clover, likewise occurring in the central Rocky Mountain 

 region, but with lower altitudinal limits and growing on drier soil 

 than Parry's clover; and Ilayden's clover, occurring in moist soil from 

 Wyoming north along the mountains at an altitude of from 7,000 to 

 10,200 feet. 



All the clovers mentioned in the preceding pages are perennials. 

 There are only two or three species of the annual clovers native to the 

 region. xVnnual red clover [Trifolium inrolucratiim) is widely distrib- 

 uted and is by far the most valuable of the annual sorts. Few-flowered 

 clover (T. pmiciflorum) is occasionally met witli, and it is likely that 

 small-headed clover (T. microcephalum) may occur in western Colorado 

 and southwestern Wyoming* The annual clovers are all found at com- 

 paratively low altitudes. 



THE VKTCHES AND VETCHLINGS. 



Two species of the true vetches occur in this region and both are of 

 value for forage. American vetch ( Yicia americana) is found in rich, 

 moist meadows and open thickets, and is regarded as a valuable native 

 forage plant. It produces long trailing or climbing vines quite thickly 

 covered with leaves and affords a good yield of forage. Narrow-leafed 

 vetch {V. linearis) is much smaller than the preceding, occurs in drier 

 situations, and, like it, is distributed throughout the entire region. It 

 afibrds less forage than American vetch, and is less palatable, but 

 thrives on soil too dry for that si)ecies, and hence replaces it in many 

 localities. It is a hardy, aggressive plant, and rai)idly takes possession 

 of idle, broken land, under some circumstances becoming a weed, 

 although not a troublesome one. 



The vetchlings are better represented in this region than the true 

 vetches, some five or six kinds being found, of which at least three are 

 of value for forage. Tliey are not very palatable in the fresh state, 

 and hence are of more importance as hay plants. The most valuable 

 sorts are the prairie vetchlings {Lathyrus ornatus and L. poli/morphus) 

 and marsh vetchling {L. palustris). The former are found chiefly in 

 the central and southern portions of the region, while the latter occurs 

 . throughout. 



Small i)rairi(', vetchling (L. ornatii.s) is usually found in <lry ])rairies, 

 and in some parts of the region, as in southeastern Wyoming, is very 

 abundant. It fruits plentifully, and the seeds are said to be edible, 



