COMPOSITE. (COMPOSITE FAMILY.) 231 



Tribe II. EUPATORIACE^E. Heads discoid, the flowers all alike, perfect and tu- 

 Uilar, never yellow. Branches of the style thickened upward or club-shaped, obtuse, 

 very minutely and uniformly pubescent ; 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. Mikaiiia. Flowers and involucral scales only 4. Stems twining. 



5. Eupatoriuin. Involucre of more than 4 scales and the flowers few or many. Stems 



not twining. 



<- <- Achene 10-ribbed ; involucral scales striate-uerved. 



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 paii- 



icled, the involucre little imbricated. 



Tribe III. ASTEROIDE.E. 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. 



i- 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. Coarse 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. 



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



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



= = Pappus simple. 



15. Aplopappus. Heads many-flowered, many-radiate. Involucre hemispherical. Pap- 



pus of many unequal bristles. Western. 



16. Bigelovia. Heads 3- 4-flowered; rays none. Receptacle awl-shaped. Pappus a single 



row of capillary bristles. 



17. Solidago. Heads few - many-flowered ; rays 1 - 16. Pappus of numerous slender and 



equal capillary bristles. 



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



bristles shorter than the achene. 



* 2. Ray-flowers white, blue, or purple, never yellow. 



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



w- Receptacle conical. Awns none. 



19. Belli s. Achenes marginless, flattened ; pappus none. Involucral scales equal. 



20. Aphanostephus. Achenes prismatic ; pappus coroniform. Outer scales shorter. 



