SYNGENESIA. 171 



II. POLYGAMIA SUPERFLUA. 



* Corolla of the marginal florets obsolete, or wanting. Discoid. 



245. TANACETUM. Receptacle naked ; seed with a membranous 



crown ; calyx imbricated, hemispherical ; florets of the cir- 

 cumference 3-cleft, obsolete, sometimes wanting. 



247- GNAPHALIUM. Receptacle naked ; down rough, or feathery ; 

 calyx imbricated, scales filmy, coloured ; florets of the cir- 

 cumference awl- shaped. 



246. ARTEMISIA. Receptacle either naked or hairy ; down none ; 



calyx imbricated, scales rounded, converging ; florets of the 

 circumference awl shaped, entire. 



* * Corolla of the marginal florets ligulate. Radiant. 



254. BELLIS. Receptacle naked, conical ; down none ; calyx he- 



mispherical, scales equal ; seed obovate. 



255. CHRYSANTHEMUM. Receptacle naked, rather convex ; 



down none : calyx hemispherical, imbricated, scales with a 

 dilated membranous border. 



256. PYRETHRUM. Receptacle naked ; seed crowned with a bor- 



der ; calyx hemispherical, imbricated, scales rather acute, 

 membranous at the edges. 



253. INULA. Receptacle naked ; down simple; calyx imbricated ; 

 florets of the radius very numerous, linear ; anthers with 

 2 bristles at the base. 



248. ERIGERON. Receptacle naked ; down simple ; calyx imbri- 

 cated ; florets of the radius numerous, linear, very nar- 

 row ; anthers simple. 



252. SOLIDAGO. Receptacle naked, pitted ; down simple ; calyx 

 imbricated, with close scales ; florets of the radius about 5. 



