125. CoMPOsiTAE 259 



2. Stem usually leafy to the inflorescence. 



3. Heads small, 1.5-3 cm broad, the rays about 1 cm long, the 

 disk 6-10 mm broad; leaves lanceolate, acuminate, serrate, 

 petiolate, more or less scabrous on both surfaces; stem 

 glabrous or nearly so, often glaucous; sandy soil in open 

 woods, local, s. 111. Aug. -Oct H. microccphalus T. & G. 



3. Heads large, 4-9 cm in diameter, the rays 2-5 cm long. 



4. Bracts acutish or obtuse, essentially glabrous on the back, 

 ciliolate, shorter than the disk, erect, closely appressed; 

 disk usually purple-brown; leaves opposite. 

 5. Leaves lanceolate to rhombic-ovate; stems several, sca- 

 brous-puberulent ; outer bracts of the involucre 

 acutish or obtusish, ovate to ovate-lanceolate, con- 

 spicuously closely and evenly ciliolate; sandy or prairie 

 soil, locally abundant. July-Sept. \H . scaberrwius Ell.] 

 Prairie Sunflower H. rigidus (Cass.) Desf. 



5. Leaves rounded-ovate to cordate; stem solitary, villous- 



pubescent below; bracts oval to slightly obovate, 

 broadly rounded and mucronulate at apex, minutely 

 ciliolate, distinctly veined; rare, Cairo, Alexander Co., 



O. Kuntze in 1874 ..//. silphioides Nutt, 



4. Bracts lanceolate or linear-lanceolate, acuminate; disk- 

 flowers yellow. 



6. Leaves linear to linear-lanceolate, entire, 1 -veined, 4-10 



mm wide, alternate, numerous. 

 7. Stem glabrous and glaucous; leaves glabrous; bracts 

 linear-lanceolate, glabrous, striate, ciliolate; waste 

 ground. Cook Co., /. A. Steyermark 80329; adv. 



from w. U.S. [H. orgyalis DC] 



H. salicijolius A.Dietr. 



7. Stem strigose to pilosulous; leaves often revolute-mar- 



gined, dark green and scabrous above, paler beneath 

 and closely pubescent; bracts lanceolate, strigillose; 

 moist ground and thickets, occasionally in s. 111. 



Aug.-Oct H. aiigustifolius L. 



6. Leaves lanceolate to ovate, broader, more than 1 cm 

 wide. 



8. Leaves sessile or subsessile. 



9. Stem hirsute or hispidulous; leaves ascending. 



10. Stem villous-hirsute; leaves finely and densely 

 grayish-pubescent on both surfaces, ovate or 

 ovate-lanceolate, acute, 3-veined above the 

 slightly clasping base, all opposite; bracts 

 copiously pubescent; heads solitary or few; 

 rays 2-3 cm long; prairie soil, locally abim- 

 dant. Aug. -Sept. [H. canescens Michx. ; H. 

 doronicoides sensu auth., non Lam.; H. 

 pubescens Vahl] H. mollis Lam. 



