50 BULLETIN 545, U. S. DEPARTMENT OF AGRICULTURE. 



horizontal, creeping rootstocks long fibrous roots are developed. 

 The rootstock is peculiarly aromatic. 



Valerian prefers a rather porous, somewhat gravelly, and com- 

 paratively deep fertile soil, but does not require a large amount of 

 moisture, as it made average development in such soil where the 

 minimum water content was only 9 per cent. Destructive wilting 

 came, however, when the water content was reduced to between 



7 and 8.5 per cent. 



The plant begins to flower profusely about July 15, and by August 

 15 nearly all the flowers have expanded. The seed crop matures 

 from August 20 to the close of the season, some individual plants 

 never reaching maturity. The early-maturing seed in 1908 and 

 1909 germinated 21.5 and 26 per cent, respectively. On protected 

 ranges reproduction is taking place sparingly. 



Both cattle and sheep are very fond of valerian at nearly any 

 time during the summer, but it grows in greatest abundance on 

 the sheep ranges. On burns covered with dead and down timber 

 sheep search for it and graze it quite as readily as the fireweed, 

 with which it is commonly associated. Early in the season the 

 flowers, leaves, and lower portion of the stem are consumed; later 

 in the summer only the flowers and leaves are eaten. 



MOUNTAIN DANDELION. 



(Agoseris glauca.} 



Mountain dandelion, so called because of its abundance on the 

 upland ranges and similarity in appearance to the ordinary dande- 

 lion, is a milky-juiced perennial from 4 to 8 inches high. In looso 

 soils it has a sparsely branched taproot, which penetrates to a depth 

 of 1 to 2 feet, but in rocky soils the root is usually branched. The 

 oblong basal leaves, generally tapering to the apex, are smooth and 

 somewhat shiny, while the flower stalk, about a third longer than the 

 leaves, is covered sparsely with coarse hair (Plate L). The solitary 

 head of yellow flowers is borne at the summit of a naked stalk; the 

 mature seeds bear a crown of copious, slender, simple, white, bristle- 

 like hairs. 



While this species occurs to a limited extent on the lower ranges, 

 it is much more abundant on the grazing lands in the Hudsonian 

 zone. On open plateaus and well-drained glades of loose, gravelly, 

 deep, clay loam it grows most luxuriantly. It is fairly drought 

 resistant, not wilting excessively in the finely disintegrated soil in 

 which it naturally occurs until the soil-water content is reduced to from 



8 to 10 per cent. In favorable situations the stand is compara- 

 tively heavy, but ordinarily it is rather scattered. 



The flower stalks begin to appear in the latter part of July, and by 

 August 15 nearly all are in evidence. This is somewhat later than the 



