COMPOSITAE (COMPOSITE FAMILY) 



477 



Heads radiate (rarely ray less). 



Style branches of perfect flowers flat, or tipped with a distinct 



appendage; leaves mostly alternate . . 



Style branches of perfect flowers truncate or appendaged, not 



flattened; leaves often opposite. 

 Involucre not scarious. < 



Pappus never capillary. 



Receptacle chaffy V. HELIANTHEAE. 



Receptacle not chaffy VI. HELENIEAE. 



Pappus capillary VIII. SENECIONEAE. 



Involucre scarious; pappus not capillary .... 

 Anthers caudate at base; style-branches neither truncate nor ap- 

 pendaged; heads not radiate. 



Receptacle not bristly; corollas not deeply cleft 

 Receptacle long-bristly; corollas deeply cleft .... 



III. ASTEREAE. 



VII. ANTHEMIDEAE. 



IV. INULEAE. 

 IX. CYNAREAE. 



Series B. LIGULIFLORAE 



COROLLAS ALL LIGULATE AND PERFECT 

 Ligule 5-toothed at the truncate apex . . .- - v . . X. CICHORIEAE. 



Abbreviated Key to the Genera 



Tribe I. VERNONIEAE 

 Only genus 1. Vernonia. 



Tribe n. EUPATORIEAE 



. - . 2. Eupatorium. 



Achenes 5-angled . 



Achenes 8-10-ribbed or -striate. 



Involucral bracts strongly striate-nerved. 



Bracts few ........ 



Bracts numerous . . . . 



Involucral bracts faintly nerved, spirally imbricated 



3. Kuhnia. 



4. Brickellia. 



5. Liatris. 



Tribe HI. ASTEREAE 



Ray-flowers yellow, or wanting.. 

 Pappus of scales 



Heads numerous, 4 mm. or less high 6. Gutierrezia. 



Heads large and showy . 7. Grindelia. 



Pappus, in part at least, of capillary bristles. 



Pappus double, the outer series of small scales ... 8. Chrysopsis. 

 Pappus wholly of capillary bristles. 

 Rays wanting. 



Involucral bracts in vertical rows ... . . 9. Chrysothamnus. 

 Involucral bracts imbricated but not in distinct vertical 



rows 10. Isocoma. 



Rays present (sometimes wanting in Nos. 13 and 14). 

 Leaves with spinulose-tipped teeth. 



Involucral bracts chartaceous, with green tips . / . 11. Sideranthus. 

 Involucral bracts more or less foliaceous . . .12. Pyrrocoma. 

 Leaves without spinulose-tipped teeth. 



Involucral bracts foliaceous, at least in part. 

 Plant 1 dm. or more high. 



Low shrubs 14. Macronema. 



Herbaceous 18. Oreochrysum. 



Plant only a few cm. high ..... 16. Tonestus. 



Involucral bracts not foliaceous. 

 Head not corymbose. 

 Stems leafy. 



Involucral bracts cuspidate . . . .13. Oonopsis. 

 Involucral bracts not cuspidate . . . 19. Solidago. 



Stems scapose, or at least naked above / . . 15. Stenotus. 

 Heads corymbose. 



Plant woody at least at base . . . .17. Petradoria. 



Plant herbaceous. 



Outer inv jlucral bracts foliaceous . . .18. Oreochrysum. 

 None of the bracts foliaceous .... 19. Solidago. 

 Ray-flowers present, not yellow (in No. 27, rarely yellow or want- 

 ing). 



Pappus a mere crown, or of a few scales or bristles . . . 20. Townsendia. 

 Pappus of numerous capillary bristles. 



Rays evident (a few discoid forms in No. 27). 



