ORDER LXVIII. COMPOSITE. 349 



4. Leaves alternate 5 



Leaves, the lower ones opposite or whorled 22 



6. Receptacle naked 6 



Receptacle chaffy 15 



6. Pappus pilose or bristly ; 7 



Pappus consisting of scales 13 



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



Pappus similar in the ray and disk florets S 



8. Involucre consisting of a single series of scales Senocio, 11 



Involucre consisting of more than one series 9 



9. Ray florets few, inconspicuous 10 



Ray florets conspicuous ; 11 



10. Lower leaves cordate BracliycJiceta, 20 



Lower leaves not cordate Solidago, 21 



11. Achenia glabrous Prionopsis, 24 



Achenia hairy or villous 12 



12. Pappus simple, of a single series Isopappu-% 23 



Pappus double, the exterior chaffy Chrysop-sis, 26 



13. Rays pistillate IMenium, 62 



Rays neutral 14 



14. Pappus awned GaiUardia, 59 



Pappus not awned Leptopoda, 63 



15. Pappus none, or rudi mentary 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 Baldwinia, 64 



Scales of the involucre in 1 or 2 6eries 18 



18. Achenia glabrous Helianthus, 50. Helianthella, 51 



Achenia silky Actinospermum, 65 



19. The inner scales of the involucre smallest Silphium, 35 



The inner scales the largest Berlandiera, 36 



20. Receptacle conical Jiudbeckia, 47 



Receptacle elongated 21 



21. Leaves pinnately dividod Lepachys, 48 



Leaves not divided Dracopis, 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 Tetrayonotheca, 44 



25. Achenia of the disk quadrangular ffeliopsis, 43 



Achenia not quadrangular Spilanthes, 55 — Acmella. 



26. Receptacle naked Arnica, 78 



Receptacle chaffy 27 



J7. Pappus consisting of many scales Ualea, 45 



Pappus consisting of awns or teeth 23 



28. Shrubby plan ts Borrichia—Buphthalmum, bl 



Herbaceous plants 29 



29. Rays pistillate, disk sterile SO 



Rays neutral or pistillate, disk perfect 31 



80. Low plants Chrysoaonnm, 34 



Tall plants '.Silphiwn, 35 



81. Rays sterile 33 



Rays fertile 32 



S2. Receptacle flat, rays few Verbesina, 56 



Receptacle convex, rays numerous Ximencsia, 57 



$8. Ray florets inconspicuous Bidens, 54 



Ra}' florets conspicuous 84 



