S50 OKDER LXVTir. COMI'OSIT.Ii:. 



84. Achenia 4-sided Helianthus, 50 



Achenia not 4-sided .... 35 



85. Achenia compressed 36 



Achenia obconapressed C re^psis, 53 



86. Stem winged ActinonnriK .52 



Stem not winged Bidenf!, 54 



37. Leaves o{)posite '. 3?; 



Leaves alternate 39 



88. Pappus none . ..Eclipta, 32 



Pappus 1-awn Zinnia, 42 



39. Receptacle naked 40 



Eeceptacle chafly 47 



40. Pappus none Leucanthemum, 69 



Pappus present 41 



41. Pappus pilose or bristly 42 



Pa|)pus consisting of scales PcUa/oxia, &0—Polypteris. 



42. Pappus double Diplopxtppus, 18 



Pappus simple 43 



43. Rays sterile Galatella, 14 



Rays fcrti ie 44 



44. Pappus of the ra\- and disk similar 45 



Pa))pus of the ray and disk di^sirai iar BoUonia, 19 



45. Achenia usually glabrous, compressed A>iter, 16 



Achenia usually pubescent 46 



46. Achenia obconic. si ky Sericncarpus. 15 



Achenia pubescent, compressed Erigeron, 17 



47. Rays neutral 4? 



Rays pistillate 49 



4S. Leaves undivided Echinacea, 46 ' 



Leaves divided Jfaruta, 67 — Anthem is. 



49. Pappus none Partheivium, 37 



Pappus none Achillea, 88 



50. Heads homogamous 51 



Heads not homogamous 69 



51. Leaves alternate 52 



Leaves opposite or verticillate 61 



52. Receptacle naked 54 



Receptacle ch.ilfy 63 



Receptacle bristly Cirsium, SI 



53. Pappus setose Carphophorus, 7 



Pappus scaly Marshallia, 66 



54. Pappus consisting of 4 or 5 scales Stnkesia, 2 



Pappus consisting of 12— 20 scales Hymenopappun, 61 



Pa[)pus capillary or setose 65 



55. Scales of the in volucre in a sing'e series 56 



Scales of the involucre in more than one series 57 



56. Heads white, brownish, or rose color Cacdlin, 76 



Heads yellow Senecio, 77 



57. Heads paniculate Eupatn-ium, 1 1 



Heads in spikes or racemes Liatris, S 



Heads more or less corymbose 53 



58. Corolla expanded at the base Kuhnia, 9 



Corolla expanded at the summit 59 



Corolla nearly straight Eupatorium^ II 



59. Corolla palmately divided Elephuntopu!>, 3 



Corolla not palmately divided 60 



60 Achenia oblong, with double pappus Vemonin, 1 



Achenia obconic, hairy Biffloi-i.i, 22 



Achenia 10-striate BiickeUia, 10 



61. Eeceptacle chaflfy MelanCnera, 4l 



Receptacle nakfMl 62 



