198 DICOTYLEDONOUS PLANTS. 



20. E. perfoliatum Linn. : stem villous ; leaves connate-per&liale, 

 oblong, becoming gradually narrower, serrate, rugose, tomentoae be- 

 neath. E. connatum Mich. 



HAB. Swampy grounds. Can. to Flor. W. to Miss. Aug., 

 Sept. It- Stem 24 feet high, hairy, branched at the top. 

 Leaves large. Flotoers in large corymbs, white. The whole 

 plant is bitter, and is used as a tonic. Big. Med. Bot i. 33. An- 

 derson's Inaugural. Boneset. Tkorov ghwort. 



*** Involucre simple. 



21. K. aromatieum Linn. : stem paniculate at the summit ; leaves 

 petiolate, ovate, acute, 3-nerved, obtusely serrate, smooth ; flowers in 

 corymbs ; involucre simple. 



HAB. Low woods. Penn. to Flor. Aug., Sept. 2{. Stem 2 

 feet high, pubescent. Pioneers in small corymbs, large, white 

 and aromatic. 



22. E. ageratoides Linn. : leaves petioled, ovate, acuminate, 3-nerv- 

 ed, unequally and coarsely serrate, smooth ; corymb many-flowered, 

 divaricate ; involucre subsimple. E. urticcrfolium Michs 



HAB. Woods and rocky hills. Can. and N. S. W. to Miss. 

 Aug. Oct. 2i. Stem 2 feet high, round and smooth. Leayfs 

 opposite, the lower ones on long petioles and somewhat cordate. 

 flowers small, white, in small panic-led corymbs. 



30. COELESTINA. Cassiri. Spreng. 



Involucre imbricate. Receptacle naked. Acines angled, 

 with a membranaceous crown. Syngenesia. JEqualis. 



C. camdea Cassin : perennial < leaves petioled, cordate-ovate, some- 

 what obtuse, obtusely serrate, 3-nerved, scabrous; involucre many- 

 leaved ; flowers in corymbs. Eupatorium codestinum Linn. 



HAB. Woods. Penn. to Car. W. to Miss. Aug. Oct. Stem 

 2 3 feet high, pubescent. Leaves on petioles, opposite, some- 

 times deltoid. Flowers hi close fastigiate corymbs, fragrant, 

 light blue. Involucre about 30-leaved, 40 60-flowered. 

 



SUBORDER V. JACOBEjB. 

 31. MIKANIA. 



Involucre 4 '6-leaved, equal, 4 6 flowered. Receptacle 

 naked. Style long, deeply -cleft. Pappus pilose. 



Syngenesia. JEqualis. 



1. Jf. fcandens Willd. . stem climbing, smooth ; leaves cordate, re- 

 pand-toothed, acuminate, with-the lobes divaricate and unequal ; flow- 

 rs in corymbs. Eupatorium scandens LAnn. 



HAB. Low grounds. Can. to Car. July Sept. I/. A twin- 

 ing plant. Flower 9 bku'sh- white, in axillary corymbs. 



Climbing Thorougkwors. 



