99 2 FLORA. 



lucre depressed, its bracts ovate or oblong, usually long-acuminate or aristate; 

 chaff of the receptacle 3-cleft; achenes obovate- oblong, appressed-pubescent, or 

 nearly glabrous. On prairies, etc., Minn, to the N. W. Terr., Mo. and Tex. 

 Much larger in cultivation ; an occasional escape in the east. July-Sept. 



4. Helianthus petiolaris Nutt. PRAIRIE SUNFLOWER. (I. F. f. 3901.) 

 Annual, similar to the preceding species, but smaller and with smaller heads; stem 

 strigose-hispid or hirsute, 3-10 dm. high. Leaves petioled, oblong, ovate, or ovate- 

 lanceolate, rough on both sides, usually paler beneath than above, 3-7 cm. long, 

 entire, or denticulate, obtuse or acutish at the apex, mostly narrowed at the base; 

 heads 4-7 cm. broad; involucre depressed-hemispheric, its bracts not hispid-ciliate, 

 acute, or short-acuminate; achenes villous-pubescent, at least when young. On 

 dry prairies, Minn, to the N. W. Terr, and Ore., south to Mo., Tex. and Ariz. 

 Found rarely in waste places farther east. June-Sept. 



Helianthus petioliris cknus Britton. Leaves ovate, white-canescent beneath. Neb. 

 to Tex. and N. Mex. 



Helianthus petiolaris pktens (Lehm.) Rydb. Heads larger, long-peduncled, the 

 peduncles fleshy toward the top ; leaves large, long-petioled. Neb. and Mo. 



5. Helianthus atrorubens L. HAIRY WOOD SUNFLOWER. PURPLE-DISK 

 SUNFLOWER. (I. F. f. 3902. ) Perennial ; stems hirsute below, often minutely 

 pubescent above, branched at the summit, 6-15 dm. high. Leaves hirsute on both 

 sides, or canescent beneath, mostly thin, ovate or ovate-lanceolate, acutish, dentate 

 or crenate- dentate, 10-25 cm - l n > 3- IQ cm - wide; heads not numerous, slender- 

 peduncled, about 5 cm. broad; involucre hemispheric, its bracts oblong to obovate, 

 obtuse, ciliolate, appressed; receptacle convex, its chaff acute, entire, or 3-toothed; 

 rays 10-20; achenes obovate, truncate, finely pubescent, about 4 mm. long; pap- 

 pus usually of 2 lanceolate awns. In dry woods, Va. to Fla., west to Ohio, Minn., 

 Mo., Ark. and La. Aug. -Oct. 



6. Helianthus scaberrimus Ell. STIFF SUNFLOWER. (I. F. f. 3903. ) Per- 

 ennial; stems simple or little branched, hispid or scabrate, 5-25 dm. high. Leaves 

 thick, coriaceous, serrate or serrulate, very scabrous on both sides. 15 cm. long, 

 5-17 cm. 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 ; 

 heads solitary or few, 5-7 cm. broad; involucre hemispheric, its bracts ovate, 

 acute, ciliate; receptacle-convex, 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, Minn, to 111., Ga. and Tex. Aug. -Sept. 



7. Helianthus subrhomboideus Rydb. RHOMBIC-LEAVED SUNFLOWER. 

 Stem simple, sparingly hirsute, usually tinged with red. Leaves opposite, firm, 

 very scabrous, 3 -nerved, slightly serrate, the basal ones broadly ovate to obovate - 

 spatulate, those of the stem rhomboid-ovate to rhomboid- lanceolate, short-petioled, 

 5-10 cm. long, the uppermost very small; heads 1-3, 2.5-4 cm. in diameter; bracts 

 of the involucre oblong, acutish, densely white-ciliate. Plains, S. Dak. to Sas- 

 katch., Neb. and Mont. July-Sept. 



8. Helianthus occidentalis Riddell. FEW-LEAVED SUNFLOWER. (I. F. f. 

 3904.) Perennial; stems appressed-pubescent or sometimes nearly glabrous, slen- 

 der, mostly simple, 69 dm. high. Leaves mainly basal, firm, ovate or oblong- 

 lanceolate, obtuse or obtusish at the apex, narrowed at the base, 3-5 -nerved, ser- 

 rulate or entire, mostly scabrous above, pubescent beneath, with slender petioles ; 

 heads several or solitary, 4-6 cm. broad; involucre hemispheric, its bracts lance- 

 olate or ovate-lanceolate, acute or acuminate, generally ciliate, appressed; recep- 

 tacle convex, its chaff acute; rays 12-15; achenes truncate and pubescent at the 

 summit; pappus of 2 lanceolate-subulate awns. In dry soil, Ohio to Minn., south 

 to Fla. and Mo. Aug.-Sept. 



Helianthus occidentalis Dowelli&nus (Curtis) T. & G. Leaves broader and more 

 numerous, smooth or nearly so on both sides. D. C. to N. Car. and Ga. 



9. Helianthus laevigatus T. & G. SMOOTH SUNFLOWER. (I. F. f. 3905.) 

 Stems slender, from a perennial root, simple or little branched, glabrous, or some- 

 what glaucous, 6-12 dm. high. Leaves nearly all opposite, firm, glabrous, lance- 

 olate, short-petioled, or the upper sessile, serrulate or entire, pale beneath, acumi- 

 nate, narrowed at the base, 7-15 cm. long, 1-4 cm. wide, the margins sometimes 



