OOMPOSITJL l^T 



1. C. LANCEOLATUM, Scop. Common Thistle. 



SUm branched., hairy; leaves decurrcnt, pinnatifid, hisped above, woolly bpn«ft| 

 mgments divaricate and spinous; scales linear-lanceolate, spinous, outer ones spre**- 

 ing. 



Pastures and roadsides, common every where, introduced. July— Sept. Bien* 

 del. St'tn 2 to 4 feet high, winged by the deeurrent leares . which are white with 

 deciduous webby hairs beneath, armed with formidable spines at all points. HtaeU 

 numerous, large, purple. 



** Leaves sessile. 



2. C. altissimum, Spreng. Tall Thistle. 



Stern downy, branching, leafy to the heads ; leaves roughish hairy above, whi'key 

 with close wool benoath ; radicxl leaves petioled, pinnatiiid; stem leaves oblong-laar 

 eeolate, sinuate toothed; scales ovatc-lanccolate, spinous, appressed. 



Old fields and open woods, common. Per. Aug., Sept. Sinn 3 to 8 feet high. 

 Ltaves o to S inches long, and 1 to 6 wide, oblong-lanceolate, undulate-pinnatind,. 

 or undivided, the lobes or teeth prickly, those from the base pinnatifid ; lo*i- 

 short, oblong or triangular, i/ead^large. Flowers purple. 



3. C. DISCOLOR, Spreng. Two-colored Thistle. 



Stem, grooved, hairy, branched, leafy ; leaves all deeply pinnatifid, sinoothish 

 above, whitened with close wool beneath, the diverging lobes 2 to 3-cleft, lineas- 

 Tanceolate, prickly-pointed ; involucre subglobose ; scries ovate spinous. 



Meadows anl open woods. Aug., Sept. Bienniel. Stem 3 to G feet high. H«ud*- 

 terminating the branches 1 inch in diameter, with reddish-purple flowers. 



4. C. VlRGINIANUM, Michx. Virginian Thistle. 



&cm woolly, slender, simple or sparingly branched, branches on long peduncle* 

 naked; haves lanceolate revolute on the margins, green above, white with close 

 wool beneath, ciliate with prickly bristles ; outer involucre scales scarcely prickly. 



Woods. July, Sept. Per. Stem 1 to 3 feet high, covered with a white down, es- 

 pecially towards the summit. Leaves entire or sparingly sinuate-lobed, the low«s 

 •ometimes deeply sinuate-pinnatifid Heads ]/ z inch in diameter ; Jiowers purple.. 



5. C. muticum, Michx. Swamp Thistle. 



Stem tall, angled, smoothish ; leaves pinnatifid, acutely cut, somewhat hairy 

 above, whitish with loose webby hairs beneath, when young ; divisions lanceolate, 

 acute, prickly pointed ; iuvolucre glutinous and webby, scales closely appressad, 

 pointless or barely mucronate. 



Swamps and lew places, common. Aug. Per. Stem 3 to 8 feet high, paniclfd 

 at the summit, the branches sparingly leatly and bearing single or few naked heads. 

 Leaves armed with spines at each uuglc. H-Mds middle sized; Jiowers deep puj- 

 ple. 



6. C. PUMILUM, Spreng. Pasture Thistle. 



Stem low, hairy, 1 to 3 flowered ; leaves lance-oblong, partly clasping, green, some- 

 what hairy, pinnatifid ; involucre round-ovate, spinose, outer scales prickly-pcinWd,. 

 the inner very slender. 



Low or dry fields, common. July, Aug. Biennial. Stem 1 to 3 feet high, low 

 and stout, bearing 1 to 3 very large heads which are somewhat iealiy braoted at 

 the base. Leaves pinnatifid, with short, and cut very prickly-margined lobaa. 

 Heads l]/^ inches broad; Jiowers fragrant 2 incheB long, pale purple; vapput 

 more than one inch long. 



7. C. horridulum, Michx. Yellow Thistle. 



SUm stout, webby-haired when young ; haves lanceolate, partly clasping, pinna- 

 Mod, the short toothed and cut lobes very spiny with yellowish prickles; he*d$ 

 serge, surrounded at the base by a whorl of leaf-like and very prickly bracts; i»v«*> 

 SKrs subglobose ; seal** linear, acute, searocly spinous. 



