IMPORTANT RANGE PLANTS. 39 



minimum soil moisture content capable of maintaining it was found 

 to be between 14 and 16 per cent. As a usual thing this plant grows 

 in close association with marsh sedges and rushes, though it fre- 

 quently produces a dense growth that crowds out other species. 



The flowers begin to unfold during the first week in July, and nearly 

 all are out by the end of the first week in August. Unlike grasses, 

 whose pollen is carried to the flower by the wind, flowers of this and 

 other onions obtain their interchange of pollen mainly through the 

 visits of insects. The seeds are comparatively late in maturing, 

 seldom beginning to ripen before the last week in August, and unfav- 

 orable weather conditions often prevent ripening. The average ger- 

 mination of the seed crop in 1908 and 1909 was 37 per cent. Con- 

 sidering the lateness of the maturing period, these figures are above 

 the average. 



The palatability of the mountain onion as compared with that of 

 other plants growing with it is pronounced. When sheep first visit 

 an area containing this particular onion in association with sedges, 

 rushes, and the usual plants of such habitats, the majority of the 

 other species are almost wholly disregarded until the onions have 

 been grazed off. Few, if any, of the marsh plants are eaten with 

 more eagerness than mountain onion. The flowers are usually 

 cropped first, but the long flat tender leaves are apparently consumed 

 with about the same relish. 



Several species of onion occur on the upland ranges, but they fur- 

 nish only a small amount of the range forage, though eaten greedily 

 by nearly all classes of stock. Of these species the small wild onion 

 {A.fibrillum) is the most important. This is the earliest of the species, 

 doubtless from the fact that it is almost entirely confined to soablands. 

 It is a small plant (Plate XXXVI) , usually not over 6 inches in height, 

 and has a cluster of white flowers which are expanded shortly after 

 the disappearance of the snow. It is valuable only as an early range 

 plant, and by August 1, like most other onions in similar situations, 

 completes its growing period, dries up, and disappears. Wild onion 

 (A. platypJiyllum) is another important high mountain form, very 

 similar economically and ecologically to A. fibrillum. 



One objection to grazing sheep upon onion is that the mutton is 

 flavored by it. This objection is not serious, however, since the 

 plants are usually grazed early in the spring when there is little or 

 no output of mutton, and the flavor is soon lost when sheep are 

 put upon other forage. 



False Hellebore. 



(Veratrum viride.) 



False hellebore, sometimes known erroneously as skunk cabbage, 

 is a close relative of the lilies. In appearance it resembles the true 

 hellebore (Veratrum album), from which it derives its common name. 



