CuMPOSIT.E. (COMPOSITE FAMILY.) 213 



1. B. COrdifolia, Ell. Stem erect, tomeutose, mostly branching; leaves 

 ovate, serrate, mostly cordate, petiolecl, the upper ones ofteu alternate ; heads 

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

 Florida, and westward. August. Stem 2 -4 high. Flowers sliowy. 



13. EUPATORIUM, Touru. 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. Acheuia 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 cylindrical involucre numerous, closely imbricated in several 

 rows, rigid, striate, obtuse : heads many-flowered: flowers bint. 



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

 hair v, at length much branched ; leaves lanceolate, acute at each end, nearly 

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

 scales of the 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 Florida (Curliss). 



3. E. heteroclinium, Griseb. Pubescent; stem branching 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, scarions, 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, 

 coarselv 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. amoenum, 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 2-3 rows, the outer 



rows shorter: heads 5 - 20-jiowered : leaves, achenia, etc. dotted with resinous 

 glands: flowers white. 



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



(except No. 16). 



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

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



