COMPOSITE. (COMPOSITE FAMILY. ^ 269 



bristly-ciliate 011 the margins, deeply pinnatifid; 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 

 1' iu diameter, 



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

 hoary -tomeutose ; leaves lanceolate, smooth above, hoary beneath, entire, the 

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

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

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

 3 high, rigid. Heads 1' in diameter. 



7. C. repandus, Kll. 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-2higli. 



8. C. horridulus, Pursh. Webby when young, at length smoothish; 

 stem thick, branching; leaves clasping, pinnatifid, armed with long and stout 

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

 scales of the involucre linear -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 of numerous short caducous bristles. Anthers cau- 

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

 leaves. Heads small. Flowers purple or white. 



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

 the uppermost ovate ; heads corymbose ; involucre smooth 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 pinuately 

 lobed ; the lobes linear, toothed ; heads sessile ; 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, 

 tlasping, toothed, prickly ; heads ovoid, sessile. IT u-ted ; spines of the invo- 

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

 g;ound. Introduced. 



