Part 82 (1/2)
[+] Heads rather large, pedunculate, radiate or rarely rayless.
68. Matricaria. Receptacle conical. Rays pistillate or none. Pappus crown-like or none.
69. Chrysanthemum. Receptacle flattish. Rays many, pistillate. Pappus none.
[+][+] Heads mostly small, discoid, corymbed or paniculate.
70. Tanacetum. Heads corymbed. Achene with broad summit; pappus a short crown.
71. Artemisia. Heads in panicled spikes or racemes. Achenes with narrow summit; pappus none.
Tribe VIII. SENECIONIDEae. Heads radiate or discoid, the involucre little or not at all imbricated, not scarious. Receptacle naked. Anthers tailless. Pappus capillary.
[*] Heads moncious or subdicious, the perfect flowers mostly sterile, and the small (ligulate or tubular) ray-flowers in more than one row (at least in the fertile heads). Style-branches obtuse, not appendaged nor hispid. Leaves all radical.
72. Tussilago. Head solitary, yellow-flowered, moncious.
73. Petasites. Heads corymbed, subdicious. Flowers white or purplish.
[*][*] Flowers all fertile. Style-branches truncate or capitellate, often appendaged. Involucral scales connivent-erect.
[+] Leaves opposite.
74. Arnica. Heads showy. Pappus rather rigid, scabrous.
[+][+] Leaves alternate. Pappus soft-capillary, copious.
75. Senecio. Heads usually radiate. Corollas yellow, 5-toothed.
76. Cacalia. Heads discoid. Corollas white or cream-colored, 5-cleft.
77. Erecht.i.tes. Heads discoid. Flowers whitish, the outer pistillate with filiform corollas.
Tribe IX. CYNAROIDEae. Flowers all tubular and perfect (the outer ray-like and neutral in n. 82). Involucre much imbricated. Anthers caudate, long-appendaged at tip. Style-branches short or united, obtuse, unappendaged, smooth, with often a p.u.b.escent ring below. Pappus mostly bristly.--Leaves alternate.
[*] Achenes attached by the base. Flowers all alike.
[+] Leaves not p.r.i.c.kly. Style-branches partly distinct. Filaments glabrous.
78. Arctium. Involucral scales hooked at the tip. Pappus of short rough bristles.
[+][+] Leaves p.r.i.c.kly. Style-branches coherent, usually a p.u.b.escent ring below.
79. Cnicus. Pappus bristles plumose. Receptacle densely bristly.
80. Carduus. Pappus-bristles not plumose. Receptacle densely bristly.
81. Onopordon. Pappus-bristles not plumose. Receptacle deeply honeycombed.
[*][*] Achenes attached obliquely. Marginal flowers often enlarged and ray-like.