166 45. COMPOSITE. 



ft Receptacle without scales. Heads discoidal. 



(18.) 17. ARTEMISIA. Florets of the disk perfect, of the ray 

 fern, slender in 1 row; or all herm. and tubular. Involucre 

 roundish. Phyll. imbricated. Receptacle naked or hairy. 

 Fr. obovate, with a small epigynous disk, without pappus. 



(19.) 18. TANACETUM. Florets as in Artemisia. Involucre 

 hemispherical. Phyll. imbricated. Receptacle naked. Fr. 

 oblong, angular, with a large epigynous disk (as broad as the 

 fruit), crowned with a slight membranous border. 



tft Receptacle scaly. Pappus 0. 



(20.) 12. ANTHEMIS. Heads heterogamous, radiant. Florets 

 of the ray fern., or neuter, ligulate, in 1 row ; of the disk 

 herm., tubular. Receptacle convex or conical. Phyll. im- 

 bricated, of few rows. Fr. terete, or obtusely tetragonal, 

 without pappus, but with a more or less prominent margin. 



[ANACYCLUS. Fr. compressed, winged at the edges. Other- 

 wise like AnthemisJ] 



(21.) 13. ACHILLEA. Heads heterogamous, radiant. Florets 

 of the ray fern., ligulate, short ; of the disk herm., tubular ; 

 tube plane-compressed, 2-winged. Receptacle narrow, slightly 

 elevated. Involucre ovate or oblong. Phyll. imbricated. 

 Fr. compressed, without pappus. 



(22.) 14. DIOTIS. Heads homogamous, discoidal. Florets 

 herm., tubular ; tube compressed, with 2 auricles at the base. 

 Receptacle convex with concave downy-topped scales. Inv. 

 bellshaped. Phyll. imbricated. Fr. compressed, crowned 

 with the persistent auricled tube of the cor. ; pappus 0. 



C. Pappus of 2 5 stiff bristles. Receptacle scaly. 



(23.) 11. BIDENS. Heads homogamous, discoidal, sometimes 

 radiant. Florets (of the ray neuter, ligulate ;) of the disk 

 herm., tubular. Receptacle flat. Phyll. in 2 rows, outer 

 row spreading. Branches of the style surmounted by short 

 cones. Fr. compressed, angular, rough at the edges ; the 

 angles terminating in 2 5 stiff retrorsely hispid bristles. 



Suborder II. CYNAROCEPHALE^l. 



Florets all tubular. Style swollen below its branches. 



a. Anthers with 2 bristles at their base. 

 24. SAUSSUREA. Florets all herm., tubular, Phyll. imbri- 



