220 COMPOSITE. (COMPOSITE FAMILY.) 



4 1. Cforotta of the ray and disk ydlow : branches of the style tipped with a pointed 



or acute appendage. 



* Achenia wingless, wedge-oblong, fiat, 2-awned or 2-toothed: scales of the outer invo- 

 lucre leafy, rejlexed: leaves opposite, petiolea, generally pinnately or ternately com- 

 pound, the leajlets serrate : biennials ? (Plants with the aspect of Bidens, but 

 the awns barbed upwardly.) 



+-Rays wanting. 



1. C. diSCOidea, Torr. & Gr. Smooth, diffusely branched; leaves ter- 

 nately divided; leaflets ovate-lanceolate, pointed, coarsely serrate; heads panicu- 

 late-corymbed ; outer involucre of 3 - 5 foliaceous bracts usually much longer than 

 the heads ; achenia hairy ; the awns or teeth as long as the corolla, barbed upward. 

 Wet places, Ohio and southward. July - Sept. Plant 1 - 2 high. 



2. C. bidentoides, Nutt. Dwarf, diffusely branched, smoothish ; leaves 

 lanceolate-linear, cut-toothed, tapering into a petiole ; awns slender, upwardly 

 barbed, much longer than the corolla or the bristly young achenium. Near Phil- 

 adelphia, Nuttall. A very obscure species. 



- *- Rays conspicuous (golden-yellow and showy). 



B. C. trichosperma, Michx. (TICKSEED SUNFLOWER.) Smooth, 

 branched ; leaves short-petioled, 5 - 7-divided ; leaflets lanceolate or linear, cut- 

 toothed, or the upper leaves only 3 - 5-cleft and almost sessile ; heads panicled- 

 corymbose ; achenia narrowly wedge-oblong, bristly-ciliate above, crowned with 2 

 triangular or awl-shaped stout teeth. Swamps, Massachusetts to Virginia near 

 the coast. Sept. 



4. C. aristosa, Michx. Somewhat pubescent ; leaves 1 - 2-pinnately 



5 - 7-divided, petioled ; leaflets lanceolate, cut-toothed or pinnatifid ; heads pani- 

 cled-corymbose ; outer involucre of 10-12 leafy bracts; achenia oblong-obovate, 

 obscurely margined, bristly-ciliate, with 2-4 long and slender diverging awns (in 

 one variety awnless). Swamps, Michigan to Wisconsin, and southward. Aug. 



* * Achenia elliptical, narrowly winged, the narrowly notched summit of the wing 

 minutely lacerate-toothed : scales of the outer involucre foliaceous, much smaller than 

 the inner, all united at the base : rays obtuse, entire : leaves opposite, petioled, 3 - 

 5-divided: perennial. 



5. C. tripteris, L. (TALL COREOPSIS.) Smooth; stem simple (4- 

 high), corymbed at the top; leaflets lanceolate, acute, entire. (Chrysostem- 

 ma, Less.) Eich soil, Michigan to Illinois and southward. Aug. Heads 

 exhaling the odor of anise when bruised : disk turning brownish. 



* * # Achenia oblong, narrowly winged, minutely or obscurely 2-toothed at the sum- 

 mit : scales of the outer involucre narrow, about the length of the inner, all united at 

 the base : rays mostly entire and acute : leaves opposite, sessile, mostly 3-divided, 

 therefore appearing as if whorled: perennial (l-3 high). 



6. C. senifdlia, Michx. Leaves each divided into 3 sessile ovate-lanceo- 

 late entire leajlets, therefore appearing like 6 in a whorl : plant minutely soft- 

 pubescent. Sandy woods, Virginia and southward. July. 



Var. Stellata, Torr. & Gr. Glabrous ; the leaves narrower. (C. ftellata, 

 Nutt.) Virginia, Kentucky, and southward. 



