GENUS 66. 



THISTLE FAMILY. 



483 



15. Helianthus grosse-serratus Martens. 

 Saw-tooth Sunflower. Fig. 4475. 



Helianthus grosse-serratus Martens, Sel. Sem. Hort. 

 Loven. 1839. 



Perennial by fleshy roots and slender rootstocks ; 

 stems glabrous, glaucous, branched above, 6-io 

 high, the branches usually strigose-pubescent. Leaves 

 long-lanceolate, slender-petioled, the upper alternate, 

 the lower opposite, long-acuminate, narrowed at the 

 base, sharply serrate, or merely denticulate, the up- 

 permost entire, rough above, densely puberulent or 

 canescent beneath, 4'-8' long, 4'-i' wide ; heads sev- 

 eral or numerous, ii'-3' broad; involucre hemi- 

 spheric, its bracts squarrose, narrowly lanceolate, 

 acuminate, hirsute ; chaff linear-oblong, pubescent at 

 the summit, acute, often 3-toothed ; disk yellowish ; 

 rays 10-20, deep yellow; achenes nearly glabrous; 

 pappus of 2 lanceolate awns. 



In dry soil, Maine to Long Island, Pennsylvania, On- 

 tario, South Dakota, Missouri, Kansas and Texas. Aug.- 

 Oct. 



16. Helianthus Kellermani Britton 

 Kellerman's Sunflower. Fig. 4476. 



Helianthus Kellermani Britton, Manual 994. 1901. 



Stem 6-io high, very smooth, much branch- 

 ed above, the branches slender. Leaves nar- 

 rowly elongated-lanceolate to linear-lanceolate, 

 drooping, rather thin, distantly serrate with 

 very small teeth, long-acuminate at the apex, 

 attenuate at the base into short petioles or the 

 upper sessile, scabrate and sparingly pubes- 

 cent on both surfaces, pinnately veined, the 

 lower about 8' long and 7" wide ; branches of 

 the inflorescence pubescent ; bracts of the in- 

 volucre linear-lanceolate, about 7" long, and i" 

 wide or less at the base, ciliate, long-acumi- 

 nate; rays golden-yellow, i'-if long; chaff of 

 the receptacle linear. 



Dry soil, vicinity of Columbus, Ohio. Aug.- 

 Sept. 



17. Helianthus divaricatus L. Rough or 

 Woodland Sunflower. Fig. 4477. 



Helianthus divaricatus L. Sp. PI. 906. 1753. 



Perennial by slender rootstocks; stem glabrous 

 throughout, or pubescent at the summit, slender, 

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

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

 ticulate, 3-nerved, rough above, pubescent beneath, 

 sessile or nearly so by a truncate base, tapering 

 gradually to the long-acuminate apex, 3'-8' long, 

 J'-iJ' wide; heads few or solitary, about 2' broad, 

 borne on strigose-pubescent peduncles ; involucre 

 hemispheric, its bracts lanceolate or ovate-lanceo- 

 late, strigose or hirsute, the outer ones spreading ; 

 disk yellow; rays 8-15; chaff of the receptacle 

 apiculate; achenes glabrous; pappus of 2 short 

 subulate awns. 



In dry woodlands, Maine and Ontario to Manitoba, 

 Nebraska, Florida and Louisiana. July-Sept. 



