268 COMPOSITE. (COMPOSITE FAMILY.) 



the lowest tapering iuto a long petiole, the upper sessile. Marshes, Georgia, 

 Florida, and westward. Aug. - Sept. Stem 3- 5 high. Lowest leaves 1 

 or more long. 



TRIBE V. CYNARE^E. Heads discoid ; the flowers all tubular; the 



ones sometimes enlarged and ray-like: style thickened at the summit; the. 



stigmatic lines extending to the summit of the branches, without appendages. 







84. CNICUS, Tourn. THISTLE. 



Heads many-flowered, discoid ; the flowers all similar and perfect. Scales 

 of the involucre imbricated in many rows, all but the innermost ones usually 

 spine-pointed. Receptacle bristly. Acheuia oblong, compressed, smooth. 

 Pappus of numerous plumose hairs. Herbs, with alternate sessile or decur- 

 reut mostly pinnatifid and spiny leaves. Heads large, subglobose. Flowers 



purple or whitish. 



* Leaves decurrent. 



1. C. lanceolatUS, Hoffm. Stem hairy, branched; leaves pinnatifid, 

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

 with strong erect spines ; flowers purple. Waste ground in the upper 

 districts. Introduced. Sept. @ Stem 2 - 3 high. 



* * Leaves sessile. 



f Scales of the involucre tipped tcith spreading spines. 



2. C. altissimus, Willd. 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. August - 

 Sept. Stem 3 -10 high. Heads about 1' in diameter. Involucre some- 

 what viscid. 



Var. discolor, Gray. Leaves nearly all deeply pinnatifid, the divisions 

 narrow, 2 -3-lobed, spiue-poiiited, and fringed along the margins. With the 

 preceding. 



3. C. Nuttallii, Gray. Stem angled, paniculately branched, smooth or 

 hairy; the branches naked at the summit; leaves clasping, suft-hairv, becom- 

 ing smoothish above, pinnatifiil ; the numerous spreading lobes lanceolate, 

 3-toothed, tipped with strong spines, and ciliate on the margins ; heads numer- 

 ous, small, bractless ; scales of the involucre appressed, viscid, tipped with a 

 short, at length spreading prickle ; corolla white or pale purple. ])rv light 

 soil, Florida to South Carolina. July- August.. Stem 3 -8 high. Heads 

 8"- 10" in diameter. 



4. C. Virginianus, Pursh. 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. August -Sept. Stem 2 -3 high. Heads \' in diameter. 



- <- Scales of the involucre spineless, or the outer ones spine-pointed. 



5. C. rnuticus, Pursh. Stem tall, branching, commonly hairy ; leave.*. 

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



