COMPOSITE. (composite FAMILY.) 247 



* Leaves decurrent. 



1. C. lanceolatum, Scop. Stem hairy, branched ; leaves pinnatifid, 

 spiny, hirsute above, woolly beneath ; scales of the involucre webby, tipped 

 ■with strong erect spines; flowers purple. — Banks of the Savannah River at 

 Augusta to North Carolina, and northward. Introduced. Sept. @ — Stem 

 2° -3° high. 



* * Leaves sessile. 

 ■*- Scales of the involucre tipped with spreading spines. 



2. C. discolor, Spreng. Stem tall, hirsute, the branches leafy to the sum- 

 mit ; leaves deeply pinnatifid, smoothish, or with scattered hairs above, hoary- 

 tomentose beneath ; the divisions 2 - 3-lobed, pointed with a spine, and ciliate on 

 the margins ; scales of the involucre narrow, webby, tipped with a very slender 

 spreading spine ; flowers purple. — Margins of fields, &c. in the upper districts. 

 July -Sept. © — Stem 3° -6° high. Lower leaves 6' -12' long. Heads 

 about 1' in diameter. 



3. C altissimum, Spreng. Stem tall, pubescent ; the branches leafy to 

 the summit ; leaves rough-pubescent above, hoary-tomentose beneath, fringed 

 with fine prickles; the lowest petioled, pinnatifid; the upper sessile, entire or 

 pinnately lobed ; heads bracted ; scales of the involucre webby when young, 

 tipped with a weak prickle ; flowers purple. — Fields and thickets, Mississippi 

 to North Carolina, and northward. Aug. and Sept. — Stem 3° -10° high. 

 Heads about 1' in diameter. Involucre somewhat viscid. 



4. C. Nuttallii, DC. Stem angled, paniculately branched, smooth or 

 hairy; the branches naked at the summit ; leaves clasping, soft-hairy, becoming 

 smoothish above, pinnatifid ; the numerous spreading lobes lanceolate, 3-toothed, 

 tipped with strong spines, and ciliate on the margins ; heads numerous, small, 

 bractless ; scales of the involucre appressed, viscid, tipi)ed with a short, at length 

 spreading prickle ; corolla white or pale purple. (Cnicua glaber, A7/.) — Dry 

 light soil, Florida to South Carolina. July and Aug. — Stem 3° - 8° high. 

 Heads 8" -10" in diameter. 



5. C. Virginianum, Michx. Stem slender, simple or sparingly branched, 

 hoary-tomentose ; leaves linear, or linear-lanceolate, rigid, smooth above, hoary 

 beneath ; the margins revolute, toothed or pinnatifid, and spiny ; scales of the 

 involucre viscid, spiny ; flowers purple. — Pine-barren swamps, Florida, and 

 northward. Aug. and Sept. — Stem 2° - 3° high. Heads ^' in diameter. 



•1— H— Scales of the involucre spineless, or the outer ones spine-pointed. 



6. C. muticum, Michx. Stem tall, branching, commonly hairy ; leaves 

 with scattered hairs above, pubescent or at length nearly smooth beneath, bristly- 

 ciliate on the margins, deeply pinnatifid; the lobes lanceolate, 2 -3-toothed, 

 spiny; scales of the involucre unarmed, webby, viscid; flowers purple. — 

 Swamps in the upper districts. Aug. and Sept. — Stem 3° -8° high. Heads 

 1' in diameter. 



7. C. Iiecontei, Torr. & Gray. Stem simple, or with 1-3 nearly naked 

 branches, hoary-tomentose ; leaves lanceolate, smooth above, hoary beneath, 

 entire, the margins fringed with bristly hairs, and spiny ; the earliest ones pin- 



