COMPOSITAE 



189 



III. 



Involucre dotted with oil glands. 

 Involucre not dotted with oil glands. 

 Pappus none. 

 Pappus of 5-8 scales. 

 Pappus of 2-3 awns. 

 Pappus a short crown. 



Pappus of disk flowers of capillary bristles. 

 Bracts in a single series. 

 Bracts strongly imbricated. 

 Heads V or more broad. 

 Leaves spinulosely serrate. 

 Leaves not spinulosely serrate. 

 Heads 6^^ or less broad. 



Pappus of 5-8 bristle-like chaii. 

 Pappus of uumerous capillary bristles. 

 Disk flowers more numerous than ray 



flowers. 

 Kay flowers more numerous than disk 

 flowers. 



IV. 

 Pappus none. 



Pappus of 2-4 bristles and short scales. 

 Pappus of numerous capillary bristles. 

 Rays not the width of the disk. 

 Rays longer than the disk. 



Involucre imbricated in 1-2 rows. 

 Involucre imbricated in 2-several rows. 



V. 



Disk flowers not ripening seeds. 

 Achenes wing-margined. 

 Achenes wingless. 

 Disk flowers ripening seeds. 

 Leaves opposite. 

 Achenes 3-4 sided. 

 Ray flowers fertile. 

 Ray flowers not fertile. 

 Achenes strongly flattened. 



Pappus of two small teeth or none. 

 Pappus of 2-6 barbed bristles. 

 Leaves alternate. 

 Receptacle conic or columnar. 

 Achenes 4-angled or terete. 

 Achenes flat, wing-margined. 

 Receptacle flat to low conic. 



Pappus of two small scales or awns. 

 Achenes not winged. 

 Achenes winged. 

 Pappus of 6-12 scales. 



VI. 



Involucral bracts not strongly fimbrillate. 

 Rays reddish-purple. 

 Rays white. 

 Disk flowers not ripening seeds. 



36. BOEBERA. 



33. 

 34. 



7. 

 40. 



Flaveeia. 

 Helenium. 

 Grindelia. 

 Tanacetum. 



44. Senecio. 



17. 



Prionopsis. 



Inula. 



6. Amphiachyris. 



10. 



SOLIDAGO. 

 EUTHAMIA. 



39. Chrysanthemum. 



11. boltonia. 



14. Leptilon. 



13. Erigeron. 



12. Aster.' 



19. SiLPHIUM. 



20. Engelmannia. 



22. Heliopsis. 

 27. Helianthus. 



29. Coreopsis. 



30. BiDENS. 



24. Rudbeckia. 



25. Ratibida. 



27. Helianthus. 



28. Verbesina. 

 35. Gaillardia. 



26. Beauneria. 



