376 COMPOSITE senecio 



to obovate and oblong-obovate, rather long-peduncled, the margin from 

 merely repand-denticulate to more conspicuously though sparingly 

 toothed: heads less than % inch high, in a loose unequally-branched 

 corymb terminating the remotely bracted stem : both disk and ray flowers 

 very light yellow. On dry wooded banks in Beaver Canon, Idaho," 



S. Giobonsii Greene Pitt, ii, 20. Stems stout, simple, 3 feet high or 

 more, leafy throughout : leaves rather fleshy, short-petioled, 3 inches long 

 deltoid-lanceolate, acute, entire or with a few irregular teeth near the base : 

 heads radiate, 6 lines high, disposed in a lax somewhat dichomotous cyme : 

 involucre campanulate, calvculate-bracted at base. Halt-marshes at the 

 mouth of the Columbia river." 



*+ ++ Tall with corymbosely cymous and radiate heads : involucre 

 setaceously few-bracteolate, campanulate or narrower : leaves nearly 

 membranaceous. 



S. triangularis Hook. Fl. i, 332. Rather stout, glabrate, stem sim- 

 ple, 2-5 feet high bearing several or somewhat numerous heads in a corym- 

 biform open cyme : leaves all more or less petioled and thickly dentate, 

 deltoid-lanceolate or the lower triangular hastate or deltoid-cordate and 

 the uppermost lanceolate with cuneate base: heads about half-inch high, 

 involucre campanulate, mostly 25-30-flowered, the oblong-linear, rays 6- 

 12. In wet ground on the high mountains, British Columbia to Califor- 

 nia and the Rocky Mountains. 



S. subvestitus Howell Eryth. iii, 35. Densely floccose-woolly through- 

 out: stem simple, 1-2 feet high, from short spreading rootstocks, leafy to 

 the top : leaves lanceolate, obscurely hastate, the lowest subcordate, all 

 petiolate, 1-2 inches long, strongly denticulate : heads several in a close 

 cyme, radiate, half-inch high, involucre campanulate, many-flowered with 

 or without calyculate setaceous bracts at base. In wet meadows, top of the 

 Siskiyou mountains near Waldo, Oregon. 



S. serra Hook I.e. Strict, 2-4 feet high, very leaty, sometimes sim- 

 ple and bearing rather few, somewhat large heads, commonly branching 

 at summit, then bearing numerous corymbosely paniculate smaller heads : 

 leaves 4-6 inches long, all lanceolate and tapering to both ends, sessile by 

 a narrow base, or the lowest short petioled, usually with the whole mar- 

 gin thickly serrate or serrulate with very acute salient teeth : involucre 

 oblong-cam panulate, 20-30 flowered : rays 5-8, oblong linear. Along streams, 

 eastern Oregon to Idaho, Wyoming and Colorado 



Tar. integriusculus Gray Syn. Fl. i, Pt. 2, 386. Heads smaller, (3 or 

 4 lines high) and narrower, fewer-flowered : leaves minutely serrate or den- 

 ticulate or the upper entire, sometimes all entire or nearly so generally 

 shorter and smaller or broader and not acuminate. Common from 

 Eastern Oregon to California and Wyoming. 



f *" Stems either few-leaved or with the upper leaves reduced in 

 size; the infloresence therefore naked : none with linear leaves. 



++ Tall and simple-stemmed, from a coarsely fibrous cluster of 

 roots : leaves fleshy-coriaceous, all entire or barely denticulate. 



S. hydrophyllus Nutt. 1. c. Very glabrous and smooth sometimes 

 glaucous: stems robust, 2-4 feet high, strict: leaves lanceolate with strong 

 midrib and obsolete veins ; radical oblanceolate and stout-petioled, some- 

 times a foot long and nearly 2 inches wide; upper cauline sessile or partly 

 clasping: heads numerous in a branching corymbiform cyme, 5 lines high, 

 short pedicelled: involucre narrowly campanulate, slightly bracteolate, its 

 bracts 8-12 : rays 3-6, small, sometimes none. In water or wet places, 

 British Columbia to California, Along the Columbia river above the Dalles. 



