COMPOSITE. (composite FAMILY.) 239 



4. MIKANIA, Willd. Climbing Hemp-weed. 



Heads discoid, 4-flowered. Involucre of 4 scales. Receptacle small. Flow^ 

 ers, achenes, etc., as in Eupatorium. — Twining perennials, climl)in<^ bushes, 

 with opposite commonly heart-shaped and petioled leaves, and corymbose-pan- 

 icled flesh-colored flowers. (Named for Prof. Mikan, of Prague.) 



1. M. SCandens, L. Nearly smooth, twining ; leaves somewhat triangu- 

 lar-heart-shaped or halberd-form, pointed, toothed at the base. — Copses along 

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



5. EUPATORIUM, Tourn. Thorough wort. 



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 capillary barelv 

 roughish bristles. — Erect perennial herbs, often sprinkled with bitter resinous 

 dots, with generally corymbose heads of white, bluish, or purple blossoms, ap- 

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

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



§ 1. EUPATORIUM proper. Receptacle flat. 



* Heads cylindrical, 5 -15 flowered ; the purplish scales numerous, closely im- 



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

 ample jnostly whorled leaves, and flesh-colored flowers. 



1. E. purpiireum, L. (Joe-Pte Weed. Trumpet- Weed.) Stems tall 

 and stout, simple ; leaves 3-6 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. amdenum, Gray. Low; leaves fewer, ovate or oblong ; heads few, 

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



* * Heads 3-2Q-floicered ; involucre of S - \5 more or less hnbricated and unequal 



scales, the outer ones shorter ; flowers lohite. 



-^ Leaves all alternate, mostly dissected ; heads panicled, very small, 3-5 floicered. 



2. E. foeniculaceum, Willd. (Dog-Fexnel.) Smooth or nearly so, 

 paniculately much-branched (3-10° high); leaves 1 - 2-pinnately parted, fili- 

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



*- -^ Leaves long -petioled, the upper ones alternate; heads 12 - 15-flowered, in 



compound corymbs. 



3. E. serotinurQ, 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. 



•^ •*- -f- Leaves sessile or nearly so, with a narroiv base, mostly opposite ; heads 



mostly 5-flowered. 

 = Involucral scales with white and scarious acute tips. 



4. E. album, L. Rouyhish-hairy (2° high) ; leaves oblong -lanceolate, 

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



