318 FLORA OF PHILADELPHIA. ■ 



**Leaves petioled, vertioillate in 3's-6's, or the upper opposite. 

 Leaves rugose, pubescent; inflorescence depressed. 2. E. maculatum. 



Leaves nearly glabrous; inflorescence pyramidal. 



Leaves sharply serrate. 3. E. purpureum. 



Leaves crenate. 4. E. trifoliatum. 



***Leaves opposite (rarely in 3 's) or the uppermost alternate. 



flnvolucral bracts imbricated in 2 or more series, the outer shorter. 

 Leaves, at least the lower, slender-petioled. 5. E. serotinum. 



Leaves all sessile, short-petioled or connate-perfoliate. 

 Leaves not clasping nor connate-perfoliate. 

 Leaves narrowed at the base. ' 



Bracts of the involucre acute or cuspidate. 



Leaves linear-lanceolate, coarsely toothed, 4-12 mm. wide. 



6. E. leucolepis. 

 Leaves oblong to lanceolate, coarsely toothed, 1-4 em. wide. 



7. E. album. 

 Bracts of the involucre obtuse. 



Leaves linear, crowded, usually entire, obtuse. 



8. E. hyssopifoliwm. 

 Leaves lanceolate, oval or oblong, usually serrate. 



9. E. Torreyanwm. 

 Leaves rounded, obtuse or truncate at the base. 



Plant glabrous; leaves lanceolate, long-acuminate. 



10. E. sessilifoliwn. 

 Plants pubescent ; leaves <ovate to oblong, acute or obtuse. 



Leaves ovate-oblong to lanceolate, mostly rounded at the 



base, usually obtuse. 11. E. verbenaefolium. 



Leaves broadly ovate, crenate-dentate, mostly truncate at 



the base, obtusish. 12. E. rotundifolium. 



Leaves ovate, dentate, acute. 13. E. pubeseens. 



Leaves clasping or connate-perfoliate at the base. 



Leaves connate-perfoliate; involucral bracts acfute. 



14. E. perfoliatum. 

 Leaves merely clasping; involucral bracts obtuse. 



15. E. resinosum. 

 fflnvolueral bracts in 1 or 2 series, all equal or nearly so. 



Eeceptacle flat; flowers white. 



Leaves thin, 5-12 cm. long, sharply dentate, acuminate. 



16. E. ageratoides. 

 Leaves thiekish, 2-5 cm. long, blunt-toothed, acute or obtusish. 



17. E. aromaticum. 

 Eeceptacle conic; flowers blue or violet. 18. E. ooelestinum. 



1. Eupatorium capillifolium (Lam.) Small. Dog-fennel. M. p. 921. Bal- 



last. Autumn. 

 Philadelphia— Philadelphia Navy Yard, C. F. Parlcer (B. C). 



2. Eupatoritjm maculatum L. Joe-pye-weed. M. p. 921. Moist soil. Late 



summer. 



3. Eupatorium purpureum L. Joe-pye-weed, Trumpet-weed. M. p. 921. 



Low grounds. Late summer. 



4. Eupatorium trifoliatum L. M. p. 921. Moist soil. Summer. 



Delaware— Tinicum, Dr. Geo. Smith (B. Sm.). Northampton — Easton, 

 Dr. T. C. Porter (B. Sm.). 



5. Eupatorium serotinum Michx. M. p. 922. Ballast. Autumn. 



Philadelphia— Philadelphia Navy Yard, C. F. Parlcer (B. C). Dela- 

 ware— Darby Creek, Adingham (St.). 



6. Eupatorium leucolepis T. & G. M. p. 922. Sandy bogs. Late summer. 



