COMPOSITAE 309 



b. Anthers with elongated, cartilaginous mostly connate appendages at the 

 tip. Tribe IX. CYNAREAE. 



Tribe I. VERNONIEAE, 

 Pappus double : heads not glomerate. i. Vernonia. 



Pappus single : heads glomerate. 2. Elephantoptts. 



Tribe II. EUPATORIEAE. 

 Achenes 3-5-angledj not ribbed. 

 Upright herbs : involucral bracts more than 4. 3. Etjpatorium. 



Twining vines : involucral bracts 4 or fewer or rarely more. 



4. WiLLUGBAEYA. 



Achenes 8-io-striate or 8-io-ribbed, not angled. 

 Heads in panicles or corymbs ; involucral bracts strongly striate-nerved. 



5. Ktjhnia. 

 Heads in spikes or racemes : involucral bracts faintly striate or smooth. 



6. Laciniaria. 

 Tribe III. ASTEREAE. 



Plants with perfect flowers, at least not dioecious. 

 Ray-flowers with yellow corollas (white in one species of SoHdago). 

 Pappus, at least that of the disk-flowers, double, i. e., an outer series of 

 scales or short bristles and an inner one of capillary bristles. 



7. Chrysopsis. 

 Pappus wholly of capillary bristles. 



Ray-flowers fewer than those of the disk : receptacle alveolate. 



8. Solidago. 

 Ray-flowers more numerous than those of the disk : receptacle fimbrillate. 



9. Euthamia. 

 Ray-flowers with white or colored corollas, but not yellow. 



Pappus a mere crown, or of few awns or bristles, or wanting. 

 Receptacle conic. 10. Bellis. 



Receptacle flat or merely convex. 11. Boltonia. 



Pappus of numerous capillary bristles. 

 Pappus mainljf of a single series of bristles, sometimes accompanied by 

 a few shorter outer ones. 

 Involucre of 2 or several series of bracts. 

 Involucre narrow : bracts firm : ray-flowers few, inconspicuous. 



^2. Sericocarpus. 

 Involucre turbinate to hemispheric : bracts thin: ray-flowers usually 

 numerous and conspicuous. 13. Aster. 



Involucre of i or 2 series of bracts. 

 Ligules of the ray-flowers longer than the diameter of the disk : 



heads conspicuous. 14. Erigeron. 



I<igules of the ray-flowers not longer than the diameter of the disk : 



heads inconspicuous. 15. Leptilon. 



Pappus manifestly double, the bristles of the inner series longer than 



those of the outer. 



Ray-flowers with white ligules : leaves with relatively broad blades. 



16. Doellingeria. 

 Ray-flowers with purple ligules : leaves with linear blades. 



17. lONACTIS. 

 Plants with dioecious flowers. 18. Baccharis. 



