ORDER LXVIII. — COMPOSITE. 349 



1 Leaves alternate S 



Leave?, the lower ones opposite or whorled 'iJ'i 



5. Receptacle naked •> 



lieceptacle chaffy 15 



6. Pappus pilose or bristly 7 



Pappus consisting of scales 13 



7. Pappus diflfcrent 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, 77 



Involucre consisting of more than one series 9 



9. Ray florets few, inconspicuous. 10 



Ray florets conspicuous 11 



10. Lower leaves cordate BrachychoEtn, 20 



Lower leaves not cordate Solidago, 21 



11. Achenia glabrous Frionopsis, 24 



Achenia hairy or villous 12 



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



Pappus double, the exterior chaflfy ChryaopfiVi, 26 



13. Eiiys pistillate Ilelenium, 62 



Kays neutral 14 



14. Pappus awned GaiUardin, 59 



Piippus 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 , Baldwijiia, 64 



Scales of the involucre in 1 or 2 series 13 



18. Achenia glabrous Heliant7iu% 50. Helianthella, 51 



Achenia silky Actinospermum, 65 



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



The inner scales the largest Berktndiera, 36 



20. Receptacle conical Rudbeckia, 47 



Receptacle elongated 21 



21. Leaves pinnately divided Lepachys, 4S 



Leaves not divided Drucopis, 49 



22. Pappus none 23 



Pappus present 26 



23. Leaves lobed or cleft Polymnia, 33 



Leaves not divided 24 



24. Leaves petiolate 25 



Leaves uot petiolate Tetragonotheca, 44 



25. Achenia of the disk quadrangular l/eliopsis, 43 



Achenia not quadrangular Sjnlanthes, bo—Aomella. 



26. Receptacle naked Arnica, 7S ^ 



Receptacle chaflfy 2. 



27. Piippns consisting of many scales Halea, 45 



Pappus consisting of awns or teeth 25 



28. Shrubby plants Bornchia—BupJUhalmum, b\ 



Herbaceous plants 29 



29. Rays jnstillate, disk sterile 80 



Rays neutral or pistillate, disk perfect 31 



80. Low plants ChryKogonum, 84 



Tall plants SUphimn, 85 



81. Rays sterile ^ 



Rays fertile •^•' 



S2. Receptacle flat, rays few Vovbeeina, f.6 



Receptacle convex, rays numerous Ximencsia, 5i 



•V?. Ray florets inconspicuous Bidont, 5t 



Jiay florets cnn-picuons *'* 



