composite:, (compositk family.) 231 



Tribe II. KUPATORIACE^. Heads discoul, the M..wt;rM all alike, perfect and tu- 



l)iil.ir, never yelluw. Branches f)f the style thickened upward or club-shaped, obtuse, 

 very minutely and uniformly imbescent ; the stigmatic lines indistiuct. 



♦ l'ai)pus a row of hard scales. 



3. Sclerolepis. Head niany-llowercd. Scales of the involucre e<iual. 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. £ui>atoriuiu. Involucre of iiioru than 4 scales and the H<j\vers few or many. Stems 



n<it twining. 



*- t- Acliene 10-ribbed ; involucral scales striate-nerved 



6. Kulinla. Pappus very strongly plumose. Scales of the involucre few. 



7. BrickelHa. Involucral scales in several series. Pappus merely scabrous. 



8. Liatris. Pappus plumose or only barbcllate. Corolla red-purple, strongly .^-lobe«l. 



Heads spicate or racemose, the involucre well imbri(;ated 



9. Trllisa. Pappus rauiutely barbellate. Corolla rose-purple Heads corymbed or pau- 



iclod, the involucre little imbricated. 



Tribe III. ASTEKOIDE^E. Heads discoid, the flowers all alike and tubular ; or else 

 radiate, the outer ones ligulate and i)istillate. Anthers not caudate at base. Bi-anchea 

 of the style in the perfect flowers flat, smooth up to where the (;onspicuou.s marginal 

 stigmatic lines abruptly terminate, and prolonged above this into a flattened lance-shaped 

 or triangular ajjpendage 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. 

 •t- 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. 



Pajipus of several short chaffy scales. Sulfrutescent : leaves very narrow. 



11. Amphiacliyris. 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-flouered. Flowers all fertile. Pappus of -J - 8 rigid 



caducous awns. Coarse herbs with toothed leaves. 



■t- t- Pappus (at least of the disk) of copious slender or caitillary 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. Clirj'sopsis. 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. 

 10. Bigelovia. Heads 3- 4-flowered ; rays none. RecepUcle awl-shaped. Pappus a single 

 row (jf capillary bristles. 



17. SoIic1ag:o. Heads few -many-flowered ; raysl-lG. Pappus of numerous slender an. 1 



eijual capillary bristles. 



18. Brachych.neta. Heads 8 - 10-flowered, clustered ; rays 4 or 5. I'appus 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 awn.i. 



♦+ Receptacle conical. Awns none. 



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



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



