COMPOSIT.E. (composite FAMILY. J 269 



bristly-ciliate on the margins, deeply pinuatificl; the lobes lanceolate, 2-3- 

 toothed, spiny ; scales of the involucre unarmed, webby, viscid ; flowers purple. 



— Swamps in the upper districts. August - Sept. — Stem 3° - 8° high. Heads 

 r in diameter, 



6. C. Lecontei, Gray. Stem simple, or with 1 -3 nearly naked branches 

 hoary-tomentose ; leaves lanceolate, smooth above, lioary beneath, entire, the 

 margins fringed with bristly hairs, and spiny ; the earliest ones piuuatifid ; 

 scales of the involucre cuspidate, viscid, not webby ; flowers purple. — Pine 

 barren swamps, Florida, Georgia, and westward. July- August. — Stem 2°- 

 3° high, rigid. Heads 1' in diameter. 



7. C. repandus, Ell. Webby throughout when young; stem simple, 

 very leafy ; leaves oblong-linear, clasping, the margins undulate and closely 

 fringed with bristly spines ; heads mostly solitary ; flowers purple. — Dry 

 pine barrens, Florida to North Carolina. June- July. Stem l°-2° high. 



8. C. horridulus, Pur,sh. Webby when young, at length smootliish ; 

 stem tliick, branching ; leaves cla.sping, pinnatifid, armed with long and stout 

 spines ; heads large, surrounded by a whorl of linear pectinate spiny bracts ; 

 scales of the involucre liuear-subulate, spine-pointed ; flowers purple or yel- 

 lowish. — Sandy soil, Florida, and northward. April -May. — Stem l°-3'^ 

 high, often purple. 



85. ARCTIUM, L. Burdock. 



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

 of the globose involucre imbricated, coriaceous, with subulate spreading 

 hooked tips. Eeceptacle flat, bristly. Achenia oblong, compressed, trans- 

 versely rugose. Pappus o'f numerous .shoi-t caducous bristles. Anthers cau- 

 date at the base. — Biennial branching herbs, with large cordate petioled 

 leaves. Heads small. Flowers purple or white. 



1. A. Lappa, L. Leaves undulate on the margins, pubescent beneath; 

 the upperniost ovate ; heads corymbose ; involucre smootii or webby. — Waste 

 places, North Carolina. Introduced from Europe. 



86. CENTAUREA, L. Star Thistle. 



Heads many-flowered ; the marginal flowers mostly large and sterile. 

 Scales of the involucre imbricated. Receptacle bristly. Achenia compressed. 

 Pappus of rough bristles in one or more rows, sometimes wanting. — Herbs. 

 Leaves alternate. Heads solitary. 



1. C. Calcitrapa, L. Stem diffusely branched, hairy ; leaves pinnately 

 lobed ; the lobes linear, toothed ; heads .ses.sile ; involucre spiny ; pappus none. 



— North Carolina. Naturalized. — Flowers purple. 



2. C. SOlstitialis, L. Stem branching, woolly ; lowest leaves pinnati- 

 fid, the upper sessile, entire ; heads small, ovate, glabrous ; involucre spiny ; 

 pappus double. — Coast of North Carolina. Introduced. 



3. C. Benedicta, L. Stem low, spreading, villous ; leaves oblong, 

 clasping, toothed, prickly ; heads ovoid, sessile, bracted ; spines of the invo- 

 lucre pectinate ; flowers yellow ; achenia 10-toothed ; pappus double. — Waste 

 ground. Introduced. 



