Order 10.— COMPOSITE. 467 



hairy; pappus in 3 series, the outer 10-toothed, the 2 inner each 



10-bristled. — Oriental herbs. 



C. benediotua L. Lvs. somewhat deourrent; dentate and spiny; iuvol. doubly 

 spinous, woolly, braoteate. — (D Native of Persia, Tauria and Greece. About 2f 

 high, with yellow flowers. Sparingly naturalized. June. — It was formerly in 

 great estimation in medicine, but is now considered worthless, if § 



95. ONOPOR'DON, Vaill. Cotton Thistle. Heads discoid, homo- 

 gamous ; involucre ventricous, imbricate with spreading, spinous scales ; 

 receptacle deeply alveolate ; pappus copious, capillary, scabrous ; achc- 

 nia 4-angled. — Large, branching herbs, with decurrent leaves. 



O. acanthium L. Invol. scales spreading, subulate ; lvs. ovate-oblong, decun-ent, 

 sinuate, spinous, woolly on both sides. — @ This fine looking thistle occurs natur- 

 alized in waste grounds, and is about 3f in height. The whole, plant has a white, 

 cottony appearance. Stem winged by the deourrent leaves, which are unusually 

 large. Involucre round, cottony, spinous. Mowers purple. July, Aug. § Eur. 



96. CIR'SIUM, Tourn. (Ouicus L. Muhl.) Thistle. (Gr. Kipaog, 

 a swelling of a vein, which this plant was supposed to heal.) Heads 

 discoid, homogamous ; involucre subglobous, of many rows of spi- 

 nous-pointed, imbricated scales ; receptacle bristly ; style scarcely 

 divided ; pappus copious, plumous ; aohenia compressed, smooth. — 

 Herbs with alternate lvs., generally armed ,with spinous prickles. Fls. 

 cyanic. 



* Leaves decurrent on the stem more or less. Scales tipped with spines Nos. 1, 2 



* Leaves not decurrent. — Heads involucrate with a whorl of 12 to 20 spiny bracts No. 8 



■ — Heads naked. — Flowers ochroleucons. Scales prickly No. 4 



— Fls. purple.— Lvs. whitc-tomentous beneath.. Nos. 5 — 7 



— Lvs. green. — Stem low, simple.. No.s. 8, 9 



— Stem tall, branched. .No. 10 



1 C. lanoeolatum Scop. Common TmsTLE. Lvs. decurrent, pinnatifid, hispid, 

 the segments divaricate and spinous ; hds. several, ovoid, viUous ; scales lanceolate, 

 tipped with a spine, spreading, — (^ Common in borders of fields, roadsides, N. 

 Eng. and Mid. States, always distinguished by the deourrent leaves. St. 3 to 4f 

 high, winged by the deourrent leaves which are white and woolly beneath, 

 armed with formidable spines at all points. Fls. numerous, large, purple. InvoL 

 scales, webbed, each ending in a spine. Jl. — Sept. 



2 C. Leodntii Torr. & Gr. Slender, simple, with one head; lvs. linear-lanceolate, 

 more or less decurrent, with a few spinous teeth, glabrous above, white-floccoua 

 beneath, invol. ovoid, arachnoid when young; scales not spinous, merely mucro- 

 nate or acuminate-pointed. — Ga. to La. St. about 2f high. Hd. large, (I' or 

 more diam.) terminal. 



3 C. horrf dulum Mx. Lvs. sessile, pinnatifid, acutely cut, spinous ; hds. invested 

 with an external invol. of about 12 to 20 very spinous bracts; scales sharp-pointed, 

 but unarmed. — ig) Found in meadows and hiUs, N. Eng. to Fla. St. 1 to 3f high, 

 invested with wool. Lvs. somewhat clasping, woolly and hairy, armed with stiff 

 spines. Hds. large (1' diam.), with yellowish white coroUas, the scales webbed. 

 Aug. 



/?. ElliOttii. Corollas purple, 2' long. Bracts about 12. — South (Elliott). Fla., 

 near Quincy. 



4 C Pitoheri, Torr. & Gr. White-tomentous ; lvs. rigid, pinnately paijted, mar- 

 gins revolute, segm. long, linear, toothed or entire, spinous ,-,. hds. axillary; scales 

 arachnoid, acumindte, tipped with a weak, spreading prickle. — Sandy lake shores, 

 Mich, and Can. TVest. Cor. ochroleucons. Jn., Jl. 



5 C. discolor Spreng. Los. sessile, pinnatifid, rough-haired, downy beneath, 

 segm. 2-lobed, divaricate, spinous; invol. globous,- the scales ovate, appressed, 

 with spreading spines at the tip. — @ A slender thistle 3 to 6f high, much branch- 

 ed and leafy at the summit, found in thickets, N. Eng. to 111. Hds. terminating 

 the branches, 1' diam., with reddish purple corollas. <i .Jl. Aug. 



