260 American Midland Naturalist Monograph No. 7 



10. Stem more or less hispidulous or scabrous; leaves 

 lanceolate, acuminate; heads several or many, 

 panicled; waste places, particularly along 

 railroads, occasional; adv. from w. U.S. July- 



Aug. Maximilian Sunflower 



H. niaximiliani Schrad. 



9. Stem glabrous or nearly so, glaucous, slender; leaves 

 divaricate, lanceolate, acuminate, 3-veined from 

 the rounded base, scabrous on both sides; road- 

 sides and open woods, local. July-Sept 



H. divaricatus L. 



8. Leaves manifestly petioled. 



1 1 . Stem smooth or nearly so, glaucous. 



12. Leaves triple-veined from near the base, chiefly 



opposite, at least below the inflorescence, 



abruptly contracted into margined petioles. 



13. Leaves lanceolate, firm, serrate to entire, the 



lower surface hirsutulous or glaucous; 



roadsides and open woods, common. 



July-Sept H. strumosus L. 



13. Leaves elliptic-lanceolate, thin, usually con- 

 spicuously coarsely regularly serrate-den- 

 tate, the lower surface glabrous, scabrous, 

 or puberulent; dry woods, local. Aug.- 

 Oct. H. decapetalus L. 



12. Leaves l-\eined or inconspicuously 3-veined. 

 the upper alternate, remotely denticulate or 

 nearly entire, the lower ones opposite (or 

 sometimes whorled), coarsely serrate, all 

 elongate-lanceolate. acuminate, scabrous 

 above, finely shortly whitish-pubescent be- 

 neath; peduncles strigose; stem 2-4 m tall; 

 prairie soil, roadsides, borders of fields, com- 

 mon. Aug.-Oct H. grosseserratus Martens 



11. Stem scabrous or hispidulous; leaves triple-veined 

 from near the base, chiefly opposite below the 

 inflorescence. 



14. Lower surface of leaves hispidulous or short- 

 hirsute; stem scabrous-hirsute; roadsides and 

 fields, local. Aug.-Sept H. hirsutus Raf. 



14. Lower surface of leaves rather copiously 

 canescent-puberulent; stem hirsutulous or 

 antrorsely scabrous-strigillose; rhizome short, 

 often tuberous-thickened at apex; alluvial 

 soil, common. July-Oct. [H. tuberosus of 

 auth.; H. subcanescens (A.Gray) E.E.Wats.] 

 H. tomentosus Michx. 



