COMPOSIT.E. (composite FAMILY.) 213 



1. B. cordifolia, Ell. Stem erect, tomentose, mostly branching; leaves 

 ovate, serrate, mostly cordate, petioled, the upper ones often alternate ; heads 

 large, 30 - 40-flowered ; achenia nearly smooth. — Light rich soil, Georgia, 

 Florida, and westward. August. — Stem 2° -4° high. Flowers showy. 



13. EUPATOmUM, Tourn. Thoroughwort. 



Heads 3 -many-flowered. Involucre cylindrical or bell-shaped, the scales 

 in a single row, or imbricated in 2 -several rows. Receptacle flat, naked. 

 Corolla 5-toothed. Achenia 5-angled, the sides smooth and even. Pappus a 

 single row of slender rough bristles. — Perennial and mostly resinous-dotted 

 herbs, with opposite or whorled leaves, and white or purplish flowers. 

 § 1. Scales of the cijlindrical involucre numerous, closely imbricated in several 

 rows, r if/id, striate, obtuse : heads many-Jiowered: flowers blue. 



1. E. ivsefolium, L. Herbaceous; stem (3°-5°) erect, terete, rough- 

 hairy, at leugtli much branched ; leaves lanceolate, acute at each end, nearly 

 sessile, 3-uerved, sparingly serrate ; corymbs dense; heads 15-20-flowered ; 

 scales of tlie involucre very obtuse. — Mississippi, and westward. July - Nov. 



2. E. COnyzoides, Vahl. Shrubby, stem much branched (4° -6° high), 

 leaves opposite, ovate or ovate-lanceolate, acuminate, 3-nerved, serrate or 

 nearly entire ; corymb trichotomous ; heads 10-20-flowered, receptacle flat ; 

 scales of the involucre rounded at the tip ; achenium scabrous on the angles. 



— Coast of South Plorida (Curtiss). 



3. E. heteroclinium, Griseb. Pubescent; stem brauchiug above (2° 

 high) ; leaves opposite, ovate, crenate-serrate, short-petioled ; pedicels 1-3 

 in the forks of the branches, longer than the cylindrical many-flowered 

 heads ; scales of the involucre smooth, oblong, deciduous ; receptacle globular, 

 naked ; achenium smooth. — Keys of South Florida. Nov. 



§ 2. Scales of the involucre mostly loosely imbricated in few {rarely single) rows, 

 thin: receptacle flat : heads corymbose {except Nos. 17 and 18). 



* Scales of the involucre purplish, scarious, obtuse, imbricated in several rows, the 



outer ones much shorter: leaves whorled: flowers purplish. 



4. E. purpureum, L. Smooth or pubescent; stem tall, often spotted 

 or dotted ; leaves petioled, 3 -6 in a whorl, varying from lanceolate to ovate, 

 coarsely serrate, roughish ; corymbs large, compound ; heads 5- 10-flowered. 



— Swamps, rarely in dry woods. August - Sept. — Stem 3° - 10° high, solid 

 or hollow, even or grooved. 



Var. amCBnum, Gray. Leaves thin, opposite or ternate, ovate, coarsely 

 unequally and sharply serrate ; corymbs loosely flowered ; heads 3-flowered. 



— Woodlands of the upper districts. — Stem 2° -3° high. 



* « Scales of the involucre {green or white) imbricated in ^-3 rows, the outer 



rows shorter: heads 5 - 20 flowered : leaves, achenia, etc. dotted ivith resinous 

 glands: floivers white. 

 H- Heads b flowered : leaves undivided, sessile or nary-owed into a stalk-like base 

 {except No. 16). 



5. E. hyssopifolium, L. Pubescent ; leaves opposite, the ujiper ones 

 alternate, lanceolate or ovate-lanceolate, coarsely serrate or toothed, 3-ribbed 



