5. Eupatorium. Involucre of more than 4 scales and the flowers few or many. Stems not twining.
[+][+] Achene 10-ribbed; involucral scales striate-nerved.
6. Kuhnia. Pappus very strongly plumose. Scales of the involucre few.
7. Brickellia. Involucral scales in several series. Pappus merely scabrous.
8. Liatris. Pappus plumose or only barbellate. Corolla red-purple, strongly 5-lobed. Heads spicate or racemose, the involucre well imbricated.
9. Trilisa. Pappus minutely barbellate. Corolla rose-purple. Heads corymbed or panicled, the involucre little imbricated.
Tribe III. ASTEROIDEÆ. Heads discoid, the flowers all alike and tubular; or else radiate, the outer ones ligulate and pistillate. Anthers not caudate at base. Branches of the style in the perfect flowers flat, smooth up to where the conspicuous marginal stigmatic lines abruptly terminate, and prolonged above this into a flattened lance-shaped or triangular appendage which is evenly hairy or pubescent outside.—Leaves alternate. Receptacle naked (destitute of chaff) in all our species.
[*] 1. Ray-flowers yellow (in one species of Solidago whitish), or sometimes none at all.
[+] Pappus of not numerous slender bristles. Heads radiate. Involucre of firm scales with greenish tips, commonly coated with resin. West of the Mississippi.
10. Gutierrezia. Heads small, numerous. Ray and disk-flowers 3 or 4 each, all fertile. Pappus of several short chaffy scales. Suffrutescent; leaves very narrow.