COMPOSITE. ' 159 



** Heads 5 IQ-flowered. Scales of the involucre oblong, imbricate. Leaves 

 mostly ver titillate. 



5. E. purpurcumLinn. : stem simple, hollow, or nearly solid; leaves 3 6 

 in a whorl, or rarely opposite, oblong-ovate or lanceolate, more or less 

 petioled, acuminate, veiny, rough or smooth above, somewhat pubescent be- 

 neath, serrate; heads in a large corymb, 5 9-flowered. E. maculatum 

 Linn. E. verticillatum Willd. E. trifoliatum Linn. E. punctatum Wtild. 

 E. amanum Punk. 



Low grounds. Can. and throughout the U. S. Aug. Oct. Tj.. Stem 3 8 

 feet high. Leaves 2 S inches long. Flowers in a large terminal corymb, pur- 

 ple. A very variable plant. The stem is sometimes solid and purplish, and the 

 leaves three or four in a whorl, (E. verticillatum.) In other specimens the stem 

 is solid and marked with purple spots, the leaves broader, more rugose and 

 scabrous, (E maculatum.) Purple Hempweed. Joe Pye's Weed. 



*** Heads S W-flowered. Leaves petioled, opposite. 



C. E. aromaticum Linn. : stem terete, pubescent ; leaves opposite, pe- 

 tioled, ovate, acuminate, 3-nerved, coarsely and unequally serrate, somewhat 

 scabrous ; corymb somewhat panicled ; heads about 20-flowered ; scales of 

 the involucre 10 12, linear-acute, equal. E. mdissoides Wittd. E. cean- 

 otMfolium Mukl. 



Low woods. Mass, to Flor. Aug., Sept. Tj.. Stem 2 feet high, pubescent. 

 Flowers in small corymbs, large, white, and aromatic. Distinguished from the 

 next by its pubescent stem, smaller leaves and short petioles. 



Aromatic Hempweed. 



7. E. ageratoides Linn. : stem smooth, branching at the top ; leaves op- 

 posite, on long petioles, broad-ovate, acuminate, 3-nerved, unequally and 

 coarsely serrate, thin and smoothish ; heads 12 20-flowered ; scales of the 

 involucre narrow-lanceolate. E. urtica folium Mich. 



Woods and thickets. Can. to Geor. W. to Miss. Aug. -Oct. 1\.. Stem 23 

 feet high, somewhat branched. Leaves on petioles 1 2 inches long, sometimes 

 slightly cordate. Heads in a compound corymb, more numerous than in the pre- 

 ceding, mostly 12 15-flowered. Flowers pure white, somewhat fragrant. 



Nettle-leaved Hempweed. 



**** Heads 5-flowered. Leaves alternate or opposite, rarely wkorled. 



8. E. hyssopifolium Linn.: stem pubescent; leaves linear-lanceolate, 

 3-nerved, pubescent and punctate ; lower opposite and dentate ; upper en- 

 tire, and sometimes alternate; heads 5-flowered ; scales of the involucre 10, 

 imbricate, pubescent and glandular on the back. E. linearifolium Walt. 



Sterile soil. Mass, to Flor. Aug., Sept. 1J-. Stem 1 3 feet high, Leaves 

 small, punctate. FUnoers in a terminal corymb, white. Style exserted. 



Hyssop-leaved Hempweed. 



9. E. aUissimum Linn. : stem pubescent ; leaves opposite, subsessile, 

 lanceolate, 3-nerved, attenuate at both ends, pubescent ; lower serrate in 

 the middle, upper entire ; heads in a terminal corymb, 5-flowered ; scales of 

 the involucre 10, oblong-linear, imbricate, somewhat obtuse, pubescent. 



Sandy woods. Penn. and Virg. W. to Miss. Aug. Oct. ^. Stem 37 

 feet high. Flowers in a terminal corymb, white. Tall Hempweed. 



10. E. leucolepis Torr. fy Gr. : stem puberulent ; leaves opposite, divari- 

 cate, lanceolate or linear, obtuse, closely sessile, serrate, very rough on both 

 sides, punctate, strongly 1-nerved; corymb fastigiate, caneaeent; scales of 



