208 COMPOSITiE. 



The tribes or sections of the family represented here are — 



A. Florets all tiibular and similar. 



(i) Florets blue mauve or white never yellow : involucral 

 bracts green. 



I. VERNONIE>E. Anthers cleft at the base (cells tailed) : 



stylar arms subulate : leaves usually alternate. 

 Pappus short : involucral bracts broad, leaf-like 



CENTRATHERUM. 



Pappus long : involucral bracts narrow, leaf-like . vernonia. 



II. EUPATORIE^E. Anther cells not tailed: stylar arms 



obtuse pappillate. Leaves opposite or alternate. 



Pappus of scales ageratum. 



Pappus ; anthers with short tips : sticky herb . adenostemma. 

 Pappus of slender hairs eupatorium. 



English example : eupatorium Hemp-Agrimony. 



(ii) Florets sometimes yellow : involucral bracts often spiny. 



IX. CYNAROIDEi^. Anther cells tailed : stylar arms short : 

 involucral bracts scarious or spiny : leaves alternate, 

 often spiny. 



Achenes glabrous, with horizontal base : pappus hairs feathery. 



CNICUS. 



English examples are carduus, cnicus, Carolina, and 

 OROPONDON Thistles ; centaurea ; Knapweed, Bluebottle ; 

 ARCTiuN Burdock ; serratula ; sausasurea. 



B. Outer florets wiihoitt stamens : often hut not always Ugulate. 



(i) Involucral bracts in several rows, 

 (a) Receptacle naked. 



III. ASTEROIDEi^. Stylar arms flattened and ending in a 



conical thickening : anthers not tailed : disc florets yellow. 

 Rays usually yellow, but also white or purple. 

 ■^ Heads not rayed, outer florets slender. 

 Heads spherical, purplish : receptacle tall with flat top : no 



pappus DICHROCEPHALA. 



Heads cylindrical, golden ; receptacle flat : pappus long . . . 



CONYZA. 



■^ "^ Heads rayed. 



No pappus : achenes viscid myriactis. 



Pappus copious erigeron. 



English examples : aster ; erigeron Fleabane. 



