The Manual of the Botany of the Northern United States / Including the District East of the Mississippi and North of North Carolina and Tennessee

by Asa Gray

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. SENECIONIDEÆ. Heads radiate or discoid, the involucre little or not at all imbricated, not scarious. Receptacle naked. Anthers tailless. Pappus capillary.

[*] Heads monœcious or subdiœcious, 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, monœcious.

73. Petasites. Heads corymbed, subdiœcious. Flowers white or purplish.

[*][*] Flowers all fertile. Style-branches truncate or capitellate, often appendaged. Involucral scales connivent-erect.

[+] Leaves opposite.