COMPOSITAE (composite FAMILY) 853 



d. Stems mostly leafy below, nearly naked above; leaves variable; 

 the lower ovate, obovate, or oblanceolate ; the upper much 

 reduced, often bract-like e. 

 4. Pubescence when present floccose-lanate and confined chiefly 

 to the base of the stem and to the leaf-axils f. 



f. Heads discoid 1. S. diacoideus. 



f. Heads radiate (except in S. ohovatus, var. elongatus) g. 

 g. Lower leaves obovate, occasionally subrotund or oblong ; 



stolons when well developed slender and creeping- . S. S. ohovatus. 

 g. Lower leaves subrotund to lanceolate ; the earliest leaves 

 cordate or subcordate, usually long-petloled ; stolons 

 short and stout, assurgent. 

 Basal leaves all broad-ovate, deeply cordate and relativeh' 



large 9. 5. aureus. 



Basal leaves mostly lanceolate : only the earliest ones 



subrotund, cordate, and relatively small . . .10. S. Eobbinsii. 

 g. Lower leaves oblong-oblanceolate to spatulate. usually 

 narrowed gradually at the base ; the earliest rarely 

 subrotund or oblong. 

 Stem but slightly woolly at the base, comparatively few- 

 headed 11. /S. EaUamitat. 



Stem rather densely and permanently woolly at the base ; 



heads usually numerous \2. S. Smallii. 



4. Pubescence white-lanate and more or less persistent over stem 

 and leaves (rarely in no. 13 completely absent). 

 Basal leaves subrotund-ovate to oblong-lanceolate. 

 Stem-leaves deeplj- and irregularh' divided . . .13. S. plattensis. 



Stem-leaves usually dentate, not deepl\' divided, only a 



few at most lyrate \^ S. tomentosus. 



Basal leaves oblong-obovate, oblanceolate, or spatulate. 



Eastern species 15. S. antennariifolius. 



Western species 16. 5. canus. 



e. Pubescence of crisp-hirsute or subvillous hairs, not floccose 



or lanate, rarely quite glabrous 17. S. integer rimuii. 



c. Heads larger, 1.5-2 cm. high during anthesis , . . . .IS. S. Pseudo-Arnica. 



1. S. vulgXris L. (Common Groundsel.) Low annual, 1-5 dm. bigh, 

 corj^mbosely branched, glabrate, leafy to the inflorescence ; leaves pinnatifid 

 and toothed, 1-8 cm. long, 0.5-3 cm. broad ; cahjculate bracts (bracteoles) of 

 the involucre distinctly black-tipped ; rays none ; achenes hirtellous. — Waste 

 grounds, common. July-Sept. (Nat. from Eu. ) 



2. S. visc6sDS L. Coarser, 1.5^ dm. high, viscid-pubescent and heavy- 

 scented ; leaves pinnatifid with toothed segments or 2-pinnatifid, 2-10 cm, long, 

 0.5-5 cm. broad ; calyculate bracts (bracteoles) of the involucre not black-tipped ; 

 rays minute, bright yellow. — Waste grounds, coast of e. Que. to N. E.; also on 

 ballast near Philadelphia. July-Sept. (Nat. from Eu.) 



3. S. SYLVATicus L. Stem erect, 1-7 dm. high, simple or branched, some- 

 what pubescent ; lower leaves petioled and more or less lyrate, the upper pin- 

 natifid with unequal lobes, sessile and sagittate at the clasping base, 2-15 cm. 

 long, 1-8 cm. broad ; inflorescence corymbose, naked or nearly so ; heads cylin- 

 drical ; involucre barely cahjculate; ligules but slightly surpassing the disk- 

 flowers. — Clearings and waste places, Nfd. and e. Que. to Me., chiefly near the 

 coast ; also near Painesville, O. July-Sept. (Nat. from Eu.) 



4. S. palustris (L.) Hook. Annual or biennial, loosely villous to nearly gla- 

 brous ; stem stout, 2-7 dm. high ; leaves oblong-lanceolate, irregularly toothed 

 or laciniate, the upper with a heart-shaped clasping base ; 7'ays 20 or more, 

 short, pale yellow ; pappus copious and becoming very long. — Wet grounds, la. 

 to n. Wise, N. Dak., and north w. June-Sept. (Eu.) 



5. S. glabellas Poir. (Butter-weed.) Rather tall. 2-5 dm. or more high ; 

 leaves somewhat fleshy, lyrate or pinnately divided; divisions crenate or cut- 

 lobed, variable ; heads less than 1 cm. high, in a naked corymbose inflorescence ; 

 rays 6-12, conspicuous. {S. lobatus Pers.) — Wet grounds, N. C. to centr. 111., 

 Mo., and southw. March-June. 



6. S. Jacobaea L. (Stinking Willie.) Arachnoid-tomentulose to nearly 

 glabrous ; stem erect, 2-6 dm. or more high ; basal leaves somewhat lyrate , 

 those of the stem 2-S-pinnatisect, sessile, 2-15 cm. long, 1-7 cm. broad ; inflo- 

 rescence a many-headed corymbose cyme ; heads radiate. — Roadsides, pastures, 

 and ballast, Nfd. and e. Que. to Me., and locally to Out. and N. J. July-Aug. 

 (Nat. from Eu.) 



