CAEDUACEAE. 



285 



Involucre of 5-6 series of bracts : ligules of 

 the ray violet, or rarely white : achenes nar- 

 row : leaf-blades 1-rlbbed. 

 Heads with dioecious flowers : ray-flowers wanting. 



18. lONACTIS. 



10. Bacchaeis. 



Tribe IV. INULEAE. 



Ray-flowers wanting : disk-flowers with white or whitish co- 

 rollas : heads relatively small. 

 Receptacle chaffy : involucre of few bracts. 20. Gifola. 



Receptacle naked : Involucre of many bracts. 

 Plants dioecious or polygamo-dioecious. 



Pappus-bristles of the staminate flowers thickened 



above : plants stoloniferous. 21. Antennaeia. 



Pappus-bristles not thickened : plants not stolon- 

 iferous. 22. Anaphalis. 

 Plants not dioecious : flowers all fruit-producing. 23. Gnaphalium. 

 Ray-flowers present ; corollas yellow : heads relatively large. 24. Inula. 



Teibb V. HBLIANTHEAE. 



Disk-flowers perfect, but not fruit-producing. 



Achenes short, thick or turgid : pappus wanting. 

 Achenes obcompressed, 3-ribbed. 

 Achenes laterally compressed, closely striate. 

 Achenes markedly "flattened : pappus present, sometimes 

 obsolete. 

 Ray conspicuous : ligules yellow, spreading : heads 

 mostly showy. 

 Ray-flowers in 2 or 3 series : achenes falling away 



free. 

 Ray-flowers in 1 series : achenes adnate to 2 or 3 

 bractlets and falling away with them. 

 Ray inconspicuous : ligules white or whitish, erect or 

 nearly so : heads not showy. 

 Disk-flowers fruit-producing. 



Corollas of the ray persistent on the achenes. 

 Corollas of the ray deciduous, or wanting. 



Pappus a mere crown or a cup, or of few teeth, awns, 

 or bristles. 

 Achenes, at least those of the disk, not compressed : 

 bractlets of the receptacle mostly concave or 

 clasping. 

 Bractlets of the receptacle mere chaffy subulate 

 awns or bristles : ray-flowers with white 

 ligules. 

 Bractlets of the receptacle broad, concave or 

 clasping. 

 Receptacle conic to columnar. 

 Receptacle flat or convex. 



Achenes not much flattened, wingless, 



erect : leaves not decurrent. 

 Achenes flattened, winged, widely spread- 

 ing : leaves decurrent. 

 Achenes very flat : bractlets of the receptacle flat 

 or at least not clasping. 

 Pappus of 2 flmbriolate awns, scales of teeth, or 



a mere border or obsolete. 

 Pappus of 2-0 awns or teeth, upwardly or 

 downwardly barbed or hispid. 

 Pappus of numerous scales. 



30. 



POLYMNIA. 

 POLYMNIASTECIM. 



SiLPIIIUM. 



Cheysogonum. 



Paethenium. 

 Heliopsis. 



Teibe VI. HELENIEAE. 



A single genus in our range. 



38. Helenium. 



Tribe VII. ANTHEMIDEAE. 

 Receptacle chaffy. 



Heads small : involucre not flattened, obovoid to campanu- 



late : achenes flattened. 

 Heads large : involucre depressed, hemispheric : achenes 

 terete or angled. 

 Receptacle naked or sometimes merely pubescent. 

 Ray-flowers normally present. 

 Ray-flowers wanting. 



39. Achillea. 



40. Anthemis. 



41. Cheysanthejium. 



42. Tanacetcm. 



