ORDER LXVIII. COMPOSITE. 351 



62. Pappus coroniform Ccelestina, 4 



Pappus not coroniform 63 



63. Pappus consisting of scales 64 



Pappus capillary or setose 65 



64. Flowers blue or white Ageratum, 5 



Flowers purple Sclerolepia — Sparganophoi-vs, 6 



65. Aclienia striate or ribbed 66 



Achenia angled 67 



66. Pnppus plumose Kuhnia, 9 



Pappus scabrous Btkkellia, 10 



67. Receptacle conic Canoclinium, 13 



Receptacle flat 68 



68. Scales of the involucre numerous Eupatorium, 11 



Scales of the involucre few Mikania, 12 



69. Heads monoecious, fertile flowers petalous Conyza, 27 



Heads monoecious, fertile flowers apetalous Solita—Gymnovtylis, 72 



Heads heterogamous . 70 



Heads heterocephalous 75 



Heads dioecious 76 



70. Receptacle chaffy Tta, 38 



Receptacle hir-ute Pterocaulon, 3) 



Keceptacle setose or naked 71 



71. lleceptac'e setose 72 



Keceptacle naked 73 



72. Flowers purple Cenfawea, 79 



Flowers yellow Cnicus, 80 



73. Flowers ye'low, with divided leaves Arte?7ii-v'a, 71 



Flowers purple Pluchea, 29 



Flowers white 74 



74. Scales of the involucre in one series E-echtites, 75 



Scales of the involucre imbricate Gnaphalium, 73 



75. Fertile heads 1-flowered Ambrosia, 39 



Ferr. e heads 2-flowered Xanihium, 40 



76. Shrubs Baccharis, 88 



Herbs Anteimaria, 74 



77. Pappus none Apogon, 83 



Pappus pre-ent 73 



'. ;.pus capillary 80 



Pappus noc capillary 79 



7C'. Pappus few scales and bristles Krigia, 84 



Pappus numerous scales and bristles Cynthia, 85 



60. Achenia beaked 84 



Achenia not beaked 81 



81. Flowers yellow 83 



Flowers not yellow 82 



82. Flowers usually nodding Xahalus—Prenanthes, S7 



Flowers er*ect Lygodesmia, 88 



83. Achenia flattened Sonehvs, 93 



Achenia not flattened ffieracium, 86 



84. Flowers blue JIulgedium, 92 



Flowers not blue 85 



85. Heads paniculate, numerous Lactuca, 91 



Heads solitary or very few 86 



■ .-. on a fistulous, naked scape Taraxicum, 89 



Sum simple Pyrrhopappus, 90 



