248 American Midland Naturalist Monograph No. 2 



2. Leaves elliptic-lanceolate, puberulent beneath; inflorescence loose, the 



branches spreading; woods, fields, and roadsides throughout 111. July- 



Oct V. altissima Nutt. 



1 . Leaves pubescent beneath. 



3. Bracts appressed, acute or obtuse; roadsides, pastures, and open woods, 



common. July-Sept. [V. illinoensis Gleason} V. missurica Raf. 



3. Bracts with acuminate, squarrose tips; open woods, local; chiefly in the s. 

 half of the state. July-Sept V. baUwini Torr. 



5. Elephantopus L. — Elephant's-foot 



E. carolinianiis Willd. Sandy soil in woods, and along roads, s. 111., extend- 

 ing northw. to Wabash and St. Clair counties. Aug. -Sept. 



Tribe 3. Eupatorieae 

 6. Eupatorium L. 

 L Leaves whorled. 



2. Stem green; leaves thin, sparsely puberulent on the veins beneath, not 

 rugose; inflorescence convex; heads mostly 5-7-flowered, the corollas 

 pinkish; woods throughout 111. July-Aug. Joe-pye Weed. [E. trijoliafum 

 L.; E. falcatum Michx.} E. purpureum L. 



2. Stem purplish or speckled with purplish; leaves thickish, rugose, rather 



copiously short-pubescent beneath; inflorescence flattish-topped; heads 

 mostly 9-15-flowered, the corollas rose purple; moist ground, more fre- 

 quent in the n. half of the state. July-Sept. [E. purpureum sensu auth., 



non L.] E. maculatum L. 



1 . Leaves opposite, or the upper alternate. 



3. Flowers white (rarely purplish); receptacle flat. 



4. Leaves connate-perfoliate, lanceolate, attenuate, crenate-serrate, rugose- 

 reticulate, pubescent beneath; wet ground, common. Aug. -Oct. Bone- 

 set E. perjoliatum L. 



4. Leaves not connate-perfoliate. 



5. Stem pubescent; leaves lanceolate, 3-nerved, grayish-puberulent. 



6. Leaves conspicuously petioled, sharply serrate; heads 4-6 mm. high, 

 7-15-flowered; moist ground, common. Aug. -Oct. Late Boneset 

 E. serotinum Michx. 



6. Leaves sessile or nearly so, sparingly toothed above the middle, or 



entire; heads 6-8 mm. high, about 5-flowered; woods near 



streams, and along roads. Aug. -Oct. Tall Thoroughwort 



E. altisshnum L. 



5. Stem glabrous or nearly so; leaves all opposite. 



7. Leaves sessile, lanceolate, pinnately veined, serrate; heads about 5- 



flowered; woods, local. Aug. -Oct. Upland Boneset 



E. sessilifolium L. 



7. Leaves petioled, ovate, triple-nerved, coarsely dentate; heads 10-30- 

 flowered; woods, common. July-Sept. White Snakeroot. [E. 



ageratoides L.f.; E. urticaefolium Reich.} E. rugosutn Houtt. 



3. Flowers bluish; receptacle conical; leaves ovate, petiolate, crenate-dentate. 



