COMPOSITAE (COMPOSITE 1 AMiLV) 8o? 



f . 8tems mostly leafy below, nearly naked above ; leaves variable ; 

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

 reduced, often bract-like e. 

 tf. Pubescence when present floccose-lanate and confined chiefly 

 to the base of the stena and to the leaf-axils /. 



/. Heads discoid 7. & dUooideut^ 



J. Heads radiate (except in S. ohovatus, var. ehingatiift) g. 

 g. Lower leaves obovate, occasionally subrotuinl or ohlong; 



stolons when well developed slender and creeping,' . 8. S. obovcUus. 

 g. Lower leaves subrotund to lanceolate ; the earliest leaves 

 cordate or subcordate, usually long-petioled ; stolons 

 short and stout, assurj^ent. 

 Basal leaves all broad-ovate, deeply cordate and relatively 



lai'fre 9. 5. aurexis. 



Basal leaves mostly lanceolate ; onlv the earliest ones 



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

 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 1\. S. BaUamitae. 



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 deeply and irregularly divided . . .13. S. plattenfds. 



Stem-leaves usually dentate, not deeply divided, only a 



few at most lyrate 14. 6". tomentosus. 



Basal leaves oblong-obovate, oblanceolate, or spatulate. 



Eastern species 15. /S. antennariifohuA 



Western species 16. nS. canus. 



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



or lanate, rarely quite glabrous 11. S. integerriimin. 



c. Heads larger, 1.5-2 cm." high during anthesis .... IS. S. Pneudo-Arnicd. 



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

 corymbosely branched, glahrate, leafy to the inflorescence ; leaves pinnatitid 

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

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

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



2. S. visc6sus L. Coarser, 1.5-4 dm. hi,<;h, viscid-pnbescent 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- 

 natitid 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 calyculate ; ligules but slightly surpassing the disk- 

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

 coast ; also near Painesville, 0. 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 ; rays 20 or more, 

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

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



5. S. glabellas Poir. (Bdtter-wekd.) Hather tall. 2-5 dm. or more high ; 

 leaves somewhat fleshy, lyrate or pinnately divided; divisions crcnate 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 south w. March-June. 



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

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

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

 rescence a many-headed corvmbose 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.) 



