■Genus 64.] 



THISTLE FAMILY. 



Prairie 



4. Helianthus petiolaris Nutt. 

 Sunflower. (Fig. 3901.) 



H. petiolaris Nutt. Journ. Acad. Phila. 2: 115. 1821. 



.\nnual, sitiiilar to the preceding species, but smaller 

 and with smaller heads; stem strigose-hispid or hir- 

 sute, i°-3° high. Leaves all but the lowest alternate, 

 petioled, oblong, ovate, or ovate-lanceolate, rough on 

 both sides, usually paler beneath than above, I'-j' 

 long, entire, or denticulate, obtuse or acutish at the 

 apex, mostly narrowed at the base; heads i^^'-S' 

 broad; disk brown; involucre depressed-hemispheric, 

 its bracts lanceolate or oblong-lanceolate, densely 

 canesceut, not hispid-ciliate, acute or short-acuminate; 

 achenes villous pubescent, at least when young. 



On drj- prairies, Minnesota to the Northwest Territory, 

 and Oregon, south to Jlissouri, Texas and Arizona. Found 

 rarely in waste places farther east. June-Sept. 

 Helianthus petiolaris canus Britton, Mem. Terr. Club, 5: 

 334- 1894. 



//. /ii?/;o/(2<7V var. r<2««c«Kj A. Gray, PL Wright. I: loS. 1852. Not //. ^aw^c^Mi Michx. 1803. 

 Leaves ovate, white-canescent beneath. Nebraska to Texas and New Mexico. 



Helianthus petiolaris patens fLehm.) Rydberg, Mem. Torr. Club, 5: 334. 1894. 

 Jleliantkus palens Lehm. Ind. Sem. Hamburg. 1S28. 



Heads larger, long-pedunclcd, the peduncles fleshy toward the top: leaves large, long- petioled. 

 Nebraska. 



5. Helianthus atrorubens L. Hairy Wood Sunflower. Purple-disk 



Sunflower. (Fig. 3902.) 



Helianthus atrorubens L. Sp. PI. 906. 1753. 



Perennial; stems hirsute below, often minutely pu- 

 bescent above, branched at the summit, 2°-5° high. 

 Leaves hirsute on both sides, or canescent beneath, 

 mostly thin, ovate or ovate-lanceolate, acutish, con- 

 tracted near the base into margined petioles, dentate or 

 crenate-dentate, a,'-\o' long, 1^-4' wide, the lower op- 

 posite, the upper few', distant, small, mainly alternate; 

 heads not numerous, slender-peduncled, about 2' 

 broad; involucre hemispheric, its bracts oblong to ob- 

 ovate, obtuse, ciliolate, appressed; disk purple; recep- 

 tacle convex, its chaff acute, entire, or 3-toothed; rays 

 10-20; achenes obovate, truncate, finely pubescent, 

 about 2" long; pappus usually of 2 lanceolate awns. 



In dry woods, Virginia to Florida, west to Ohio, Miss- 

 ouri, .\rkansas and Louisiana. Aug.-Oct. 



Stiff 



1824. 

 1829. 



6. Helianthus scaberrimus Ell. 

 Sunflower. (Fig. 3903.) 



H. scaberrimns Ell. Bot. S. C. & Ga. 2: 425. 

 H. rigidiis Desf. Cat. Hort. Paris, Ed. 3, 184. 



Perennial; stems simple or little branched, hispid 

 or scabrate, i°-S° high. Leaves thick, coriaceous, 

 serrate or serrulate, very scabrous on both sides, 2'- 

 -' long, )i'-2' wide, acute at the apex, narrowed at 

 the base, the lower ovate or ovate- oblong, petioled, 

 the upper lanceolate or oblong-lanceolate, sessile or 

 short petioled, all opposite, or the uppermost bract- 

 like and alternate; heads solitary or few, 2'-3' broad; 

 involucre hemispheric, its bracts ovate, acute or ob- 

 tusish, ciliate; disk purple or brown; receptacle con- 

 vex, its chaff obtuse; rays 15-25, light yellow; achenes 

 more or less pubescent, oblong-obovate; pappus of 2 

 broad scales or of 2-4 stout awns. 



Prairies, Minnesota to the Northwest Territory, south 

 to Illinois, Georgia, Texas and Colorado. .Vug. -.Sept. 



