ORDER LXVni. COMPOSITE. 351 



62. Pappus coroniform Ctxlestina, 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 Sclervlepis — Sparganophotus, 6 



65. A ch enia striate or ribbed 66 



Achenia angled 67 



66. Pappus plumose Kuhnia, 9 



Tappus scabrous Brukellia, 10 



67. Receptacle conic Conoclinium, 13 



Keceptacle flat 63 



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, ferule flowers apetalous Saliva— Gymnosty lis, 72 



Heads heterogamous TO 



Heads hett-rocephalous 75 



Heals dioecious 76 



70. Keceptacle chaffy Iva, 88 



Keceptacle hirsute Pterocaulon, 3 J 



Keceptacle setose or naked 71 



71. Keceptacle setose, ■. 72 



Keceptacle naked 73 



72. Flowers purple Ceniaiorea, 79 



Flowers yellow C'nicus, 80 



73. Flowors yellow, with divided leaves Artemisia, 71 



Flowers purple Pluchea, 29 



Flowers white 74 



74. Scales of the involucre in one series Erechtites, 75 



Scales of the involucre imbricate Gnaphalium, 73 



75. Fertile heads 1 -flowered Ambrosia, 39 



Fertile heads 2-flowered Xanthium, 40 



76. Shrubs BaccTuiris, 28 



Herbs Antenna ria, 74 



77. Pappus none Apogon, 83 



Pappus present 73 



78. Pappus capillary 80 



Pappus not capillary 79 



79. Pappus few scales and bristles Krigia, 84 



Pappus numerous scales and bristles Cynthia, 85 



80. Achenia beaked 84 



Achenia not beaked 81 



81. Flowers yellow S3 



Flowers not yellow 82 



82. Flowers usually nodding Ndbalus — Prenanthe.s, S7 



Flowers erect Lygodesmia, 88 



83. Achenia flattened Sonchus, 93 



Achenia not flattened Hieracium, SG 



64. Flowers blue Mulgedium, 92 



Flowers not blue 85 



85. Heads paniculate, numerous Lactuca, 91 



Heads solitary or very few 86 



86. Heads on a fistulous, nake^l scape Taraxicum, 89 



Stem simple Py rrhopapp-us, 90 



