PIPER FLORA OF THE STATE OF WASHINGTON. 595 



SENECIO. 



Annual; calyculate bracts of the involune several, short, closely 



appressed, distinctly black-tipped I. S. vulgaris. 



Biennials or perennials; calyculate bracts of the involucre few, 



not closely appressed, slightly or not at all black-tipped • 



(except in S. lugeiis). 

 Leaves, or some of them, pinnate or pinnatifid. 



Stems mostly leafy: leaves all pinnatifid or the lower- 

 most undivided and orbicular; pubescence if any 

 crisp-hairy, not woolly. 



Leafy to the inflorescence; leave's thin 2. S. harfordii. 



Leafy at the base, naked above; leaves thick. . . 3. S. Jiettii. 

 Stems leafy below, the upper leaves much reduced, 

 mostly pinnatifid or pinnatisect ; pubescence if any 

 white woolly. 



Herbage densely white woolly or fioccose; pubes- 

 cence usually persistent. 



Pubescence persistent except in S. fastigi- 

 afus; leaves 1 to 2 cm. broad. 



Petioles of the ba.sal leaves usually 



shorter than the blades 12. <S'. canus. 



Petioles of the basal leaves usually ex- 

 ceeding the blades. 



Leaves entire to pinnate-lobed ; up- 

 per leaf surface usually perma- 

 nently woolly 13. 5'. hmvellii. 



Leaves entire or dentate; upper 



leaf-surface often glabrate 14. S.fastigiatus. 



Pubescence fioccose, more or less evanescent ; *■ 



leaves 1 to 5 cm. broad. 



Involucral bracts and bractlets not 



conspicuously black-tipped 15. <S. elmeri. 



Involucral bracts and bractlets conspic- 

 uously black tipped 16. S. lugens. 



Herbage not densely lanate nor fioccose; pubes- 

 cence confined chiefly to-the base of the stems 

 and the leaf-axils. 



Heads discoid (except in subspecies /aZZoj;). 4. S. paucijiorus. 

 Heads radiate. 



Stems 10 to 30 cm. high; heads usually 

 solitary. 



Cauline leaves much reduced, 



bract-like 5. S. suhnudus. 



Cauline leaves when present broad 

 and subamplexicaul, closely pec- 

 tinate 6 S. ovinus. 



Stems 30 to 70 cm. high ; heads several 

 to many. 



Leaves thin in texture, the lower 



distinctly ovate 7 S. pseudaureus. 



Leaves thick in texture the lower 

 not ovate. 



Akcncs hispidulous on the 



angles 11. S. balsamitae,, 



