I 



COMPOSITE.. (COMPOSITK FAMILY.) 239 



4. MIKANIA, Will.l. CLiMiuN(i IIkmp-weed. 



Heads discoid, 4-lU)\verL'(l. Iiivuluirc of 4 scales. Kocoptacle small. Flow- 

 ers, achencs, etc., as in Eupatorium. — Twining perennials, climbing bushes, 

 with opposite commonly heart-shaped and petioled leaves, and C()ryml)Ose-pan- 

 icled flesh-colored flowers. (Named for Prof. Mi/can, of Prague.) 



1. M. SC^ndens, L. Nearly smooth, twining; leaves somewhat triangu- 

 lar-heart-sliapcil or halberd-form, ])oiiite(l, toothed at the i)ase. — Copses along 

 streams, E. New Eng. to Ky., and southward. July -.Sept. 



5. EUPATORIUM, Tourn. Tiiokoughwort. 



Heads discoid, 3 - many-flowered ; flowers perfect. Involucre cylindrical or 

 bell-shaped, of more than 4 scales. Receptacle flat or conical, naked. Corolla 

 .5-toothed. Achenes 5-angled ; pappus a single row of slender capillar}- barely 

 roughish bristles. — Erect perennial herbs, often sprinkled witii l)itter resinous 

 dots, with generally corym]>ose heads of white, bluish, or purple blossoms, ap- 

 pearing near the close of summer. (Dedicated to Eupator Mitliridates, who is 

 said to have used a species of the genus in medicine.) 



§1. EUPATORIUM proper. Receptacle fat. 



* Heads cylindrical, 5-l5-Jlowered ; the purplish scales numerous, closely im- 



bricated in several rows, of unequal length, slightly striate ; stout herbs, with 

 ample mostly whorled leaves, and fesh-colored fowers. 



1. E. purptireum, L. (Joe-Pye Weed. Trumpet-Weed.) Stems tall 

 and stout, simple ; leaves 3 -G in a whorl, oblong-ovate or lanceolate, pointed, 

 very veiny, roughish, toothed; corymbs very dense and compound. — Varies 

 greatly in size (2-12° high), etc., and with spotted or unspotted, often dotted 

 stems, etc., — including several nominal species. — Low grounds ; common. 



Var. amoenum, Gray. Low ; leaves fewer, ovate or oblong ; heads few, 

 3 - 5-flowcred. — Mountains of Va. and N. Y. 



* * Heads 3-20 fowered ; involucre of 8- 15 more or less imbricated and unequal 



scales, the outer ones shorter; fowers irhite. 



t- Leaves all alternate, mostly dissected ; heads panicled, very small, 3-5 fowered. 



2. E. fOBnicul^ceum, Willd. (Dog-Fennel.) Smooth or nearly so, 

 ])aniculately much-branched (3-10° high); leaves 1 -2-pin nately parted, fili- 

 form. — Va., near the coast, and southward. Adv. near Philadelphia. 



•*- -t- Leaves long-pet ioled, the upper ones alternate; heads 12 - 15 fowered, in 

 compound corymbs. 



3. E. serotinum, Michx. Stem pulverulent-pubescent, bushy-branched 

 (3 - 7° high) ; leaves ovate-lanceolate, tapering to a point, triple-nerved and 

 veiny, coarsely serrate (3-6' long); involucre very pubescent. — Alluvial 

 ground, Md. to Minn., E. Kan., and southward. 



t- -t- -t- Leaves sessile or nearly so, with a narrow base, mostly opposite; heads 



mostly 5-fowered. 



= Inrolucral scales with white and scarious acute tips. 



4. E. Alburn, L. lioughish-hairy (2° high) , leaves oblong-Janceolate, 

 coarsely toothed, veiny ; heads clustered in the corymb ; involucral scales close v 



