AND GENERA OF PLANTS. 411 



panulate, sparingly bracteolate; sepals about fifteen, linear, carinate, not spha- 

 celous; rays oblong, short, six to eight, about the length of the short involu- 

 crum; achenium smooth; pappus much shorter than the florets. 



Hab. The plains of Oregon, near the outlet of the VVahlamet. A remarkably tall and robust 

 species, from three to five feet high, above nearly naked and without a branch, except the sub- 

 divisions of the corymb, which may contain from forty to fifty capituli, all in one fastigiate cluster. 

 Involucrum brownish, short and rigid, the sepals with pubescent tips. Allied to S. lugens, but 

 with smaller and more numerous capituli, and fewer rays, the upper stem leaves are also those 

 which are most divided, instead of being entire. The stem and upper leaves are sometimes almost 

 hoary with rough white hairs, never arachnoidly pubescent. 



Senecio * cordatus; % , more or less hirsute, particularly the lower part of the 

 stem; stem tall and robust, subcylindric, and angularly grooved; corymb many- 

 flowered, nearly simple; lower leaves cordate-ovate, nearly entire, or repandly 

 serrulate, obtuse, long petiolate; stem leaves lanceolate, amplexicaule, serrate; 

 involucrum campanulate, rather small; sepals linear, carinate, about fifteen, 

 with black, pubescent, sphacelous tips; rays five or six, oblong, about the 

 length of the involucrum; achenium smooth, pappus a little shorter than the 

 florets. 



Hab. Alluvial situations in Oregon, near the outlet of the Wahlamet; rather rare. With the 

 preceding: flowering in June. About two and a half to three feet high. The capituli comparatively 

 small, twenty to thirty in a slightly divided corymb ; pedicels and base of the involucrum sparingly 

 bracteolate ; involucrum smooth. The stem appearing naked from the sudden diminution of the 

 leaves : the radical two to three inches broad, by three to four long, sometimes nearly entire, at 

 other times very regularly crenate. Allied to the preceding, but with a smaller and nearly simple 

 corymb, and the leaves at the base of the stem nearly as broad as long. 



Senecio *h]/drophilus; il, very smooth and robust, erect; stem cylindric, 

 fistulous and grooved; leaves lanceolate, nearly entire, or repandly denticulate; 

 cauline amplexicaule, acuminate; capituli bracteolate, paniculate; branchlets 

 subfastigiate, the corymbuli contracted, thyrsoid; involucrum small, subcam- 

 panulate; sepals about twelve, linear-lanceolate; rays about six, narrow, shorter 

 than the involucrum; achenium smooth; receptacle deeply alveolate, fim- 

 brillate. 



Hab. By the margins of ponds and springs in wet places, in the Rocky Mountains, by Ham's 

 Fork of the Colorado of the West. Leaves very smooth and rather thick, very much like those of 

 Solidago limonifolia. Stem about two feet high. The root presenting an abrupt crown with 

 circles of thick fibres. Lower leaves narrowed below, with wide sheathing bases, an inch to one 

 and a half inches wide, the petiole six to seven inches long ; stem leaves gradually becoming smaller; 



