302 CLASS XIX. ORDER I. 



florets of the margin very numerous and narrow, 

 linear. 



345. TussiLAGo. Receptacle naked, down simple; 

 fertile flowers ligalate, or toothless ; calyx simple, its 

 scales equal, somewhat membranous, equalling the 

 disc. 



346. SoLiDAGo. Receptacle naked, pitted ; down 

 simple ; florets of the margin from five to ten, remote ; 

 calyx imbricate, closed. 



347. Senecio. Receptacle naked ; down simple ; 

 calyx invested with scales, many leaved, equal ; the 

 scales dead at their tips. 



348. Aster. Receptacle naked; down simple; 

 calyx imbricate, with the lower scales spreading; 

 florets of the margin commonly more than ten. 



349. Helenium. Receptacle naked; rays chaff"y; 

 down five awned ; florets of the ray three cleft ; 

 calyx simple, many parted. 



350. Anthemis. Receptacle chafly ; seeds crowned 

 with a slight border ; calyx hemispherical ; florets of 

 the ray more than five, oblong. 



351. Achillea. Receptacle chaffy; down none; 

 calyx ovate, imbricate, unequal; florets of the ray 

 from five to ten, inversely heart shaped or roundish. 



Order III. FRUSTRANEA. Florets of 

 the centre with stamens and pistils, fertile ; those of the ray 

 with pistils only, barren. 



352. Helianthus. Receptaclechaffy; seeds crown- 

 ed with two lanceolate, chafly scales; calyx imbri- 

 cate, somewhat squarrons. 



353. Coreopsis. Receptacle chaffy ; seeds com- 

 pressed, emarginate, with two unarmed arms; calyx 

 double, each many leaved. 



