Part 79 (2/2)

Tribe II. EUPATORIACEae. Heads discoid, the flowers all alike, perfect and tubular, never yellow. Branches of the style thickened upward or club-shaped, obtuse, very minutely and uniformly p.u.b.escent; the stigmatic lines indistinct.

[*] Pappus a row of hard scales.

3. Sclerolepis. Head many-flowered. Scales of the involucre equal.

Leaves whorled.

[*][*] Pappus of slender bristles.

[+] Achene 5-angled; bristles of the pappus roughish.

4. Mikania. Flowers and involucral scales only 4. Stems twining.

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. ASTEROIDEae. 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 p.u.b.escent outside.--Leaves alternate. Receptacle naked (dest.i.tute 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.

11. Amphiachyris. Heads small. Ray-flowers 5--10; pappus coroniform.

Disk-flowers infertile; pappus of several bristle-like scales. Annual; leaves very narrow.

12. Grindelia. Heads large, many-flowered. Flowers all fertile. Pappus of 2--8 rigid caducous awns. Coa.r.s.e herbs with toothed leaves.

[+][+] Pappus (at least of the disk) of copious slender or capillary bristles.

[=] Pappus double.

13. Heterotheca. Resembling Chrysopsis, but the achenes of the ray thicker than those of the disk and without pappus or nearly so. Western.

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