COMPOSITAE (COMPOSITE FAMILY) 



477 



Heads radiate (rarely rayless). 



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 ....... 



Receptacle not chaffy ...... 



Pappus capillary 



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. 



V. HELIANTHEAE. 

 VI. HELENIEAE. 

 VIII. SENECIONEAE. 

 VII. ANTHEMIDEAE. 



IV. INULEAE. 

 IX. CYNAREAE. 



Series B. LIGULIFLORAE 



COROLLAS ALL LIGULATE AND PERFECT 

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



Abbreviated Key to the Genera 



Tribe I. VERNONIEAE 

 Only genus 1. Vernonia. 



Tribe II. EUPATORIEAE 



Achenes 5-angled 2. Eupatorium. 



Achenes 8-10-ribbed or -striate. 



Involucral bracts strongly striate-nerved. 



Bracts few 3. Kuhnia. 



Bracts numerous ......... 4. Brickellia. 



Involucral bracts faintly nerved, spirally imbricated . . 5. Liatris. 



Tribe IH. 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 involucral 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). 



