468 Order 70.— COMPOSITE. 



6 C. altissimum Spreng. Tall, branched, villous-puboscent, leafi) to the top ; lvs. 



whitish beneath, spinous-eiliate, sessile, lanceolate oblong, often sinuate-dentate, lower 

 undivided or pinnatifid petiolate, lobes or teeth spinescent. Hds. large, scales 

 ovate-lanceolate, outer one with a spreading spine at apex. — Fields and barrens, 

 Penn. and "W. States, common. St. 3 to 8f high. Lvs. 6 to 8', by 1 to G'. Hds. 

 about 1' diam., with linear-lanceolate bracts at base. El. purple or purplish 

 white. Aug. 



7 C. Virginianum Michx. Slender, mostly simple, and naked above ; lvs. 

 sessile, lanceolate, margin revolute, entire or repand-dentate, teeth spinescent, or 

 Eometimes remotely sinuate-lobed or pinnatifid, upp^r surface glabrous, under 

 surface tomentous-cancscer.t ; hds. small; invol. subglobous; scales tipped with a 

 short, spreading prickle. — Woods, Ohio, and S. States. Plant about the size of the 

 Canada thistle, clothed with an arachnoid pubescence, with few or many heads 

 (sometimes but one) which aro about V diam. Flowers purple. Apr. — Sept 

 (Carduus, L. Cnicus, Ph.) 



8 C. repandum Mx. Arachnoid when young ; lvs. crowded to the top, at length 

 green both sides, clasping oblong-linear, undulate, spinous-eiliate ; hds. 1 or 2; 

 scales, outer ovate-lanceolate, inner subulate-acuminate. — Barrens, N. Car. to Ga. 



9 C. pumilum Spreng. Hairy ; lvs. few above, green on both sides, clasping, 

 oblong-lanceolate, pinnatifid, the segm. irregularly lobed, ciliate, spinous ; lids, few, 

 very large, subtended by I to 5 bracts ; invol. round-ovate, spinous. — © A common, 

 low, turgid thistle, in roadsides, pastures, N. Kng. and Mid. States. St. 1 to 2f 

 high, stout, [striate, with 1 to 3 very largo heads of fragrant, purple fls. Aug. 

 (Cnicus odoratus Muhl.) 



10 C. muticum Mx. Lvs. pinnatifid with divaricato segments ; hds. on 

 naked 2>edimcles without bracts; invol. ovoid with unarmed, villous-araelmoid, 

 glutinous scales. — © A fine looking thistlo found in damp soils. Can. and U. S. 

 St. branching, 3 to If high. Lvs. armed with spines at each angle. Hds. 1' diam., 

 with deep purple corollas, tho scales webbed and glutinous on the back. Aug., 

 Sept. 



LI C. glaber Nutt. Tall, slender, nearly glabrous; lvs. lance-linear, rigid, with 

 spinescent, divaricate segments, the lower slightly decurrent; lids, naked, on leafless 

 stalks; scales setaceously mucronate, strongly keeled, almost glabrous, the inner 

 attenuate-acuminate. — N. Jer. to Ga. St very smooth, angled, 3 to 51* high. Lvs. 

 minutely arachnoid beneath. Hds. G" diam., truncate at base. Fls. purple. Jl. 

 Sept. 



12 C. arvense Scop. Canada Thistle, Cursed Thistle. Lvs. sessile, sinuate- 

 pinnatili 1, wavy, spinous; st. panicled; hds. numerous, small, invol. round or 

 ovate, with minute spines, scales close-pressed, ovate-lanceolate. — H Common in 

 field?, roadsides and waste places, N. Eng. to W. States, very troublesome to tho 

 farmer. Root creeping, long and tenacious of life. St 3f high, with a branching 

 panicle at top. Hds. small (4 to 5" diam.) purple, the involucre nearly thoruless, 

 and is the only part of tho plant that can be safely handled. Jl. § Eur. 



97. LAP'PA, Tourn. Burdock. (Lat. lappa, a burr, from Gr. Xa(3elv t 



to lay hold of; a characteristic term.) Heads discoid, homogamous; invo- 

 lucre globous, the scales imbricated and hooked at the extremity ; re- 

 ceptacle bristly ; pappus bristly, scabrous, caducous. — ® Coarse, Euro- 

 pean herbs. Lvs. alternate, large. 



L. major Gaert Lvs. cordate, unarmed, petioled. — Common in waste and culti- 

 vated grounds, fields. N. Eng., Mid. and W. States. Each plant is a large, coni- 

 cal, ill-scented and coarse-looking mass of vegetation, surmounted by a branching, 

 irregular panicle of ovoid heads with tubular corollas of an exceedingly delicato 

 pink color. Tho loaves are very large, with wavy edges. It has a wonderful de- 

 sign for tho dispersion of its seeds. The scales of the involucre all end in a mi- 

 nute, firm hook, which seizes hold of every thing that passes by. Jl., Aug. § Eur. 

 (Arctium Lappa L.) 



(3. Leaves pinnatifid. — Penn. (Darlington). 



