COMPOSITAE (composite FAMILY) 771 



Pribe n. EUPATORIeAE. Heads discoid ; the flowers all alike, perfect and tubular, nevei yel- 

 low. Branches of the style thickened upward or club-shaped, obtuse, very minutely and 

 uniformly pubescent ; the stigmatic lines indistinct, 



* Pappus a row of hard oval obtuse scales. 

 8. SclerolepiS. Head many-flowered. Bracts of the involucre equal. Leaves whorled. 

 * * Pappus of slender bristles. 

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



4. Eupatorium. Involucre of more than 4 bracts and the flowers few or many. Stems not 



twining. 



5. Mikania. Flowers and involucral bracts only 4. Stems twining. 



•*- +- Achene 10-rlbbed ; involucral bracts striate-nerved. 



6. Trilisa. Pappus minutely barbellate. Corolla rose-purple. Heads corymbed or pan^'cled, 



the involucre little imbricated. 



7. Brickellia. Involucral bracts in several series. Pappus merely scabrous. 



8. Kuhnia. Pappus very strongly plumose. Bracts of the involucre few. 



9. LiatriS. Pappus plumose or only barbellate. Corolla red-purple, strongly 5-lobed. Heads 



spicate or racemose, the involucre well imbricated. 



Tribe III. AST^REAE. 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 hnes abruptly 

 terminate, and prolonged above this into a flattened lance-shaped or triangular appendage 

 which is evenly hairy all around or pubescent outside. Leaves alternate. Receptacle naked 

 (destitute of chaff) in all our species. 



* Ray-flowers yellow (in one species of no. 15 whitish), or sometimes none at all. 

 t- Pappus of not numerous slender bristles ; heads radiate ; involucre of firm bracts with greenish 

 tips, commonly coated with resin. 



10. Grindelia. Heads large, many-flowered. Flowers all fertile. Pappus of 2-8 rigid caducous 



awns. Coarse herbs with toothed leaves. 



11. Gutierrezia. Heads small, numerous. Ray- and disk-flowers 3 or 4 each, all fertile. Pappus 



of several short chaff'y scales, Suff'rutescent ; leaves very narrow. 



12. Amphiachyris. Heads small. Ray -flowers 5-10 ; pappus coroniform. Disk-flowers infer- 



tile ; pappus of several bristle-like scales. Annual ; leaves very narrow. 

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

 ++ Pappus double. 



13. Heterotheca. Resembling ChrysopsU, but the achenes of the ray thicker than those of the 



disk and without pappus or nearly so. Western. 



14. ChrysopsiS. Heads many-flowered ; rays numerous. The outer pappus of very small chaflfy 



bristles, much shorter than the inner of copious capillary bristles. 

 ++ ++ Pappus simple. 



15. SolidagO. Heads few-many-flowered ; rays 1-16. Pappus of numerous slender and equal 



capillary bristles. 



16. Brachychaeta. Heads 8-10-flowered, clustered ; rays 4 or 5. Pappus a row of minute 



bristles, shorter than the achene. 



17. Aplopappus. Heads many-flowered, many-radiate. Involucre hemispherical. Pappus of 



many unequal bristles. Western. 



18. Bigelowia. Heads 3-4-flowered ; rays none. Receptacle awl-shaped. Pappus a single row 



of capillary bristles. 



* * Ray-flowers white, blue, pink, or purple, scarcely ever yellow. 



4- Pappus none or very short, with or without a few awns. 



++ Receptacle conical ; awns none. 



19. BelliS. Achenes marginless, flattened ; pappus none. Involucral bracts equal 



++ ++ Receptacle flat or con', ex ; pappus usually with awns. 



20. Chaetopappa. Achenes fusiform ; pappus of 5 or f^^wer thin chaffy scales and often alter- 



nating awns. Western. 



