426 



COMPOSITAE. 



[Vol. III. 



Helianthus Nuttallii T. & G., a low Rocky Mountain plant with smaller heads, slender usually 

 simple stem, and entire or serrulate leaves, may occur in the western part of our area. 



13. Helianthus divaricatus L. Rough 

 or Woodland Sunflower. (Fig. 3910.) 



Helianlhus divaricalus I_. Sp. PI. 906. 1753. 



Perennial by slender rootstocks; stem glabrous 

 througliout, or pubescent at the summit, slender, 

 2°-7° high. Leaves usually all opposite, divaricate, 

 lanceolate or ovate-lanceolate, firm, dentate or den- 

 ticulate, 3nerved, rough above, pubescent be- 

 neath, sessile, or nearly so b}' a truncate base, 

 tapering gradually to the long-acuminate apex, 3'- 

 8'long, ]i'-i.Yi' wide: heads few or solitary, about 

 2' broad, borne on strigose-pubescent peduncles; 

 involucre hemispheric, its bracts lanceolate or 

 ovate-lanceolate, strigose or hirsute, the outer ones 

 spreading; disk yellow; raysS-15; chafT of the re- 

 ceptacle apiculate; achenes glabrous; pappus of 2 

 short subulate awns. 



In dry woodlands, Ontario to the Northwest Terri- 

 tory, south to Florida, Nebraska and Louisiana. July- 

 Sept. 



14. Helianthus mollis Lam. Hairy 

 Suuflower. (Fig. 391 1.) 



HdianlliHS mollis Lam. Encycl. 3: S5. 1789. 



Perennial; stem stout, simple, or sparingly 

 branched above, densely hirsute or hispid, 2°-4° 

 high. Leaves ovate or ovate-lanceolate, closely 

 sessile and somewhat clasping by a broad cordate 

 base, pinnately veined, 3-nerved above the base, all 

 opposite, or the upper alternate, ascending, acute 

 or acuminate, scabrous or cinereous-pubescent 

 above, densely and finely pubescent beneath, serru- 

 late, 2'-5' long, i'-2^^' wide; heads solitary or few, 

 2'-3' broad; involucre hemispheric, its bracts 

 lanceolate, acuminate, densely villous canescent, 

 somewhat spreading; disk yellow; rays 15-25; chaff 

 canesceut at the summit; mature achenes nearly 

 glabrous; pappus of 2 lanceolate scales. 



In dry barren soil, Ohio to Georgia, west to Iowa, 

 Missouri and Texas. Aug.-Sept. 



15. Helianthus doronicoides Lam. 

 Oblong-leaved Sunflower. (Fig. 3912.) 



Helianthus doronicoides Lam. Encycl. 3: S4. 1789. 



Perennial by slender rootstocks; stems stout, 

 rough, or finely rough-pubescent, branched above, 

 3''-7° high. Leaves oblong, ovate-oblong, or ovate, 

 thick, ascending, serrate or serrulate, acute or acumi- 

 nate at the apex, narrowed at or below the middle to 

 a sessile or slightly clasping base, rough on both 

 sides.or finely pubescent beneath, somewhat 3-nerved, 

 4'-8' long, i'-2 ' .' wide; heads cotimionly numerous, 

 2^'-4' broad; involucre hemispheric, its bracts 

 lanceolate, acuminate, pubescent or hirsute, some- 

 what spreading; disk yellow; rays 12-20, 4"-6" 

 wide; achenes glabrous; pappus of 2 subulate awns. 



In dry soil, Ohio to Michigan, Missouri and Arkansas. 

 Aug.-Sept. 



