COMPOSITAE. 389 



Arctic North America and Alaska, south to Wyoming and Washington; 

 in our limits known only from the Olympic Mountains, Flett. 



Senecio hydrophilus Nutt. Perennial, wholly glabrous and slightly glau- 

 cous; stems erect, 60-100 cm. high, stout; leaves fleshy with obscure veins, 

 entire or nearly so, the basal oblanceolate, short-petioled, 10-30 cm. long; 

 cauline sessile or half-clasping, lanceolate; heads numerous, in a dense cyme, 

 short-peduncled; involucre cylindric, 6 mm. high; tegules 8-12; ray-flowers 

 small, few or sometimes wanting. 



Near the Cascades of the Columbia, Howell, perhaps not within our 

 limits. 



Senecio ochraceus Piper n. comb. {S. exallatus ochraceus Piper.) Per- 

 ennial, sparingly white-tomentose; stems erect, 30-60 cm. high; lower leaves 

 broadly ovate, subcordate, crenate-dentate to subentire, 5-8 cm. long, petioled; 

 upper leaves much reduced, sessile, lanceolate-attenuate; heads in a rather 

 close corymb; involucres campanulate, tomentose; tegules about 13, linear, 

 acute, black-tipped, 6-8 mm. long; ray-flowers pale yellow. 



British Columbia to Montana and northern California; Goat Mountains, 

 Washington, Allen. 



Senecio exaltatus Nutt. (5. oreganus Howell.) Perennial; stem simple, 

 erect, 20-120 cm. high, terete, striate, glabrous, or somewhat pubescent with 

 long flaccid jointed white hairs; lower leaves petiolate, oblong-ovate to oblong- 

 lanceolate, 10-20 cm. long, 2-8 cm. broad, obtuse, unequally dentate to sub- 

 entire, gradually narrowed to abruptly contracted at the base, glabrous or 

 more or less crisp-hirsute; upper stem-leaves soon becoming sessile and much 

 reduced; inflorescence terminating the stem in a few to many-headed corym- 

 bose cyme; heads about 1 cm. high in anthesis, radiate; tegules about 13, 

 commonly penicillate and black-tipped; akenes glabrous. 



British Columbia to Montana and Oregon; rare west of the Cascade Moun- 

 tains, but first collected by Nuttall at the mouth of the Willamette River; 

 Lake Labish, Howell (type of 5. oreganus). 



Senecio fastigiatus Nutt. Perennial; herbage thinly white tomentose; 

 stems erect, 30-40 cm. high; leaves mostly basal, lanceolate to spatulate, 

 obtuse, obscurely crenulate or entire, firm in texture, 5-7 cm. long, the lower 

 ones slender petioled, the cauline sessile and narrower; inflorescence a cyme 

 with nearly erect branches; heads 8-10 mm. high; ray-flowers yellow; akenes 

 glabrous. 



Gravelly prairies, Washington and Oregon, west of the Cascade Mountains, 



Senecio fastigiatus macounii (Greene) Greenman. Stem 30-45 cm. high, 

 simple or branched; leaves entire to coarsely erose-dentate. Differs from 

 S. fastigiatus chiefly in the dentate character of the leaves. 



Mount Constitution, San Juan County, Washington, Flett; Columbia 

 Valley, Lyall; Willamette Valley near Tangent, Oregon. 



Senecio multnomensis Greenman. Perennial; stems flcxuous, suberect, 

 30-70 cm. high, glabrous, except in the leaf axils; lower leaves oblong-oblan- 

 ceolate, 4-15 cm. long, obtuse, crenate-serrate, or more or less lyrately lobed, 

 glabrous in age; upper sessile or half-clasping; inflorescence cymose, the pe- 

 duncles elongate; heads 10-13 mm. high, rayed; tegules about 21, linear 

 lanceolate, 8-10 mm. long, acute, pale green, glabrous; ray-flowers yellow; 

 akenes glabrous. 



British Columbia to Oregon. 



Senecio suksdorfii Greenman. (5. adamsi Howell.) Perennial, floccose- 

 woolly, becoming more or less glabrate; stems 10-30 cm. high; basal leaves 

 obovate to suborbicular, crenate-dentate, slender petioled; cauline oblong- 



