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



deprived of their attractive flower heads and leaves early in the season. 

 Sheep prefer the plant to many abundant grasses, even during the 

 period when the latter are most palatable. 



BUTTERWEED. 



(Senecio triangularis.) 



Senecio triangularis is not only the largest and most abundant of 

 the butterweeds in the region studied, but also the most palatable. 

 It grows from 2 to 5 feet tall, and has a leafy stem which terminates 

 in dense clusters of 20 or 30 bright yellow flowers. The leaves are all 

 petioled and toothed. Shoots are sent up in abundance from the 

 lateral running rootstocks (Plate LV). 



Butterweed is closely confined to the higher ranges, being abundant 

 in the upper Canadian zone and throughout the Hudsonian zone. It 

 is distinctly a marsh plant and is closely restricted to situations with 

 wet or saturated soils. On creek banks, in the vicinity of springs, 

 and in swales of various kinds, it is often the chief plant. It was 

 found to wilt beyond recovery in a soil whose moisture content varied 

 from 11.5 to 14 per cent. 



Usually the flowers do not begin to appear until about the last 

 week in July, and the blooming period continues until the last week 

 in August. The seed crop begins to reach maturity when the late 

 flowers are unfolding. The ripening period continues until inclement 

 weather, the latest flowers failing to mature seeds. The seed which 

 had ripened by September 5 germinated, in 1908 and 1909, 18 and 

 26 per cent, respectively. The later maturing seed has a notably 

 lower viability. 



Early in the year butterweed is eaten with such avidity that almost 

 nothing is left. Until August 1 the lower part of the stem is the only 

 portion not consumed. As the season advances, however, only the 

 flower clusters, the upper rapidly growing terminal part of the stem, 

 and the leaves are grazed. Among late forage plants, butterweed is 

 one of the most highly relished. Since it is found only in moist situa- 

 tions, however, its amount is limited. 



Another butterweed much relished by sheep is S. columbianus, often 

 called small butterweed. In the Wallowa National Forest this species 

 occurs in scattered stand on well-drained soils throughout the Cana- 

 dian and Hudsonian zones. It begins growth early and is of value 

 for grazing only in the spring. Sheep prefer it to grasses, and eat it 

 with such ravenousness that it has little opportunity to reseed under 

 the usual grazing practice. Its relatively small size (Plate LVI), 

 different habitats, and earlier flowering period, easily distinguish it 

 from Senecio triangularis. 



