ORDER LXVIII. COMPOSITE. 405 



bristly. Florets of the ray pistillate, funnel-shaped, irregular ; 

 those of the disk staminate. Pappus consisting- of three series, 

 the exterior a toothed margin, the middle one composed of 10 

 or 12 awns, the interior one short, hairy. 



1. C. Americana, (Xutt.) Stem erect, striate, somewhat branched. 

 Leaves glabrous, sessile, oblong-ovate, repand toothed, the upper lance- 

 olate ; scales of the involucre with pectinate appendages. Heads large, 

 showy. — Pale purple. Cultivated. Louisiana, Texas. 2 — 3 feet. 



Gents LXXX.— CNI'CUS. Vaill. 

 (From knizo, to prick.) 



Heads many-flowered ; florets of the disk and ray similar. 

 Scales of the involucre coriaceous, produced into long, hard, 

 spiny, pinnate appendages. Receptacle flat, covered with capil- 

 lary bristles. Ackenia longitudinally striate. Pappus triple. 



1. C. benedic'tus. Stem villous, branching. Leaves subpinnatifid, 

 clasping, decurrent. Flowers yellow. — 0. Louisiana. 



Genus LXXXL— CIR'SIUM. Tourn. (Cnicus.) 

 (From kirsos, a swelled vein, for which the thistle was supposed to he a remedy.) 



Involucre ventricose, imbricate, with spinose scales. Florets 

 perfect. Receptacle hairy. Pappus plumose, or pilose. 



1. C. disco'lor, (Spren.) Stem erect, hairy. Leaves sessile, pinnati- 

 fid ; segments 2-lobed, spinous, hairy on the upper surface, tomentose 

 beneath. Flowers solitary, terminal, on leafy branches ; scales of the 

 involucre ovate, terminated by a long spine. Seed smooth ; pappus 

 plumose. — Purple. If. June— July. Upper dist. Car. and Geo. 



2. C. altis'simum, (Spren.) Stem erect, branching. Leaves sessile, 

 oblong-lanceolate, scabrous, tomentose beneath, dentate, ciliate, radical 

 ones pinnatifid. Flowers terminal ; involucre cylindrical, ovate ; scales 

 ovate, spinous, appressed, pale ; receptacle villous. — Purple. 21. July 

 — ~ P*- 1 pper dist. Car. and Geo. 2 — 3 feet. 



3. C. Viuginia'num, (Mich.) Stem simple, angled, tomentose toward 

 the summit. Leaves sessile, narrow-lanceolate, with spiny teeth, acute, 



ly hairy on the upper surface, tomentose beneath. Flowers soli- 

 tary, terminal; involucre ventricose; scales appressed, carinate, ovate. 

 .'iy angled, oblong; pappus plumose; receptacle bristly. — 

 Purple. 21 . June — Sept. Pine-barrens. Common. 2 — 3 feet. 



4. C. Mf run!, (Mich.) Stem erect, slender, branching. Leaves pin- 

 iiatitid. woolly, tomentose beneath; segments with spines, somewhat 



. occasionally S-lobed, pale, acute; branches naked, 1-flow- 

 ered; involucre globose; scales without spines, lanuginous. — Purple. 

 11 July — Sept. Mountains. 2 — 6 feet. Cnicus muticus, Pureh. 



5. C. gla'bkb. (C. muticum, Mich.) Stem erect, furrowed, sprinkled 

 with hair-, branching. Leaves sessile, pinnatifid, very lung, hairy along the 

 veins, spiny along the margins and angles ; segment- 3 — 5-lobed. Flow- 

 ers in panicles. Peduncles slender, slightly hairy ; scales of the involu- 



