ORDER LXVm. COMPOSITE. 349 



4. Leaves alternate 5 



Leaves, the lower ones opposite or whorled 22 



5. Receptacle naked 6 



Receptacle chaffy 15 



6. Pappus pilose or bristly 7 



Pappus consisting of 6cales 13 



7. Pappus different in the ray and disk florets Heterotheca, 25 



Pappus similar in the ray "and disk florets 8 



S. Involucre consisting of a single series of scales Senecio, 77 



Involucre consisting of more than one series 9 



9. Ray florets few, inconspicuous 10 



Ray florets conspicuous 11 



10. Lower leaves cordate BracJiy chain. 20 



Lower leaves not cordate Solidago, 21 



11. Achenia glabrous Prionopxis, 24 



Achenia hairy or villous 12 



12. Pappus simple, of a single series Isopappux, 23 



Pappus double, the exterior chaffy Chrysopxis, 26 



13. Rays pistillate Helenium, 62 



Rays neutral 14 



14 Pappus awned GaiUardia. 59 



Pappus not awned Lcptopoda, 63 



15. Pappus none, or rudimentary 20 



Pappus consisting of scales, teeth, or awns 16 



16. Leaves sessile, entire 17 



Leaves petiolate, entire Coreopsis, 53 



Leaves more or less divided 19 



17. Scales of the involucre in 4 series Biddicinia, 64 



Scales of the involucre in 1 or 2 6eries 13 



IS. Achenia glabrous Relianthella, 51 



Achenia silky Actinosperm urn, 65 



19. The inner scales of tbe involucre smallest Silpkium, 35 



The inner scales the largest Berlandiera, 36 



20. Receptacle conical IiudbecJcia, 47 



Receptacle elongated 21 



21. Leaves pinnately divided Lepachys, 4S 



Leaves not divided Diacopis, 49 



22. Pappus none 23 



Pappus present 26 



23. Leaves lobed or cleft Polymnia, 33 



Leaves not divided 24 



24. Leaves petiolate 25 



Leaves not petiolate Tetragonotheca, 44 



25. Achenia of the disk quadrangular Tfeliopsis, 43 



Achenia not quadrangular Spilant/ies, 55 — Acmella. 



26. Receptacle naked Artrica, 78 



Receptacle chaffy 27 



27. Pappus consisting of many scales Ilalea, 45 



Pappus consisting of awns or teeth 23 



28. Shrubby plants Borrichia — Buphthalmum, 81 



Herbaceous plant* 29 



29. Rays pistillate, disk sterile 80 



Rays neutral or pistillate, disk perfect 31 



30. L m plants . . Chrysogonum, 34 



Tall plants Siiphium, 35 



31. Rays sterile 83 



- senile 82 



;.tacle flat rays few Verhesina, 56 



K- ptacle convex, rays numerous Ximeiusia, 57 



33. Ray florets inconspicuous Bidcne, 64 



Ray floret! con-picuous 84 



