158 LEAFLETS OF PHILIPPINE BOTANY (Vor. I, Arr. 7 
30. SIEGESBECKIA. 
Outer involucral bracts 4, broad, in opposite pairs. 
31. ENHYDRA. 
Inner involucral bracts not embracing the achenes;. 
palea of receptacle flat, narrow. 
32. ECLIPTA. 
Inner involucral bracts not embracing the achenes; 
palea of receptacle concave, embracing the achenes. 
Ray flowers with small ligules; achenes not 
winged. 
33. BLAINVILLEA. 
Ray flowers with large yellow ligules; achenes 
thick. 
34. WEDELIA. 
Ray flowers with white or yellow ligules; achenes 
ciliate. 
35. SPILANTHES. 
Ray flowers neutral with yellow ligules; achenes 
~ 4-angled. 
36. HELIANTHUS. 
Heads heterogamous or homogamous; perfect flowers all 
fertile or neuter; achenes dorsally compressed, 2 to 4-awned 
or naked. 
Involucre single. 
37. SYNEDRELLA. 
Involuere double. 
Pappus of 2 fimbriate awns, scales or teeth or 
a mere border or wanting. 
Appendages of style arms of perfect flowers 
none or very short. 
38. COREOPSIS. 
Appendages of style arms of perfect flowers 
long. 
39. DAHLIA. 
Pappus of 2 to 6 awns or teeth, upwardly or 
downwardly barbed or hispid. 
