CO MPO sitae. 993 



roughish; heads few or solitary; involucre campanulate, its bracts lanceolate or 

 ovate-lanceolate, firm, ciliolate, the tips of the outer ones spreading; rays 5-10; 

 chaff linear; achenes slightly pubescent at the summit; pappus of 2 lanceolate or 

 ovate awns, with or without 2 intermediate scales. In dry soil, mountains oi Va. 

 and N. Car. Aug. -Oct. 



10. Helianthus microcephalusT. & G. Small Wood Sunflower. (I. F. 

 f. 3906.) Stems slender, glabrous, branched above, or rarely simple, 1-2 m. high. 

 Leaves thin or thinnish, petioled, most of them opposite, lanceolate, or the lower 

 ovate -lanceolate, rough above, canescent or puberulent beneath, long-acuminate at 

 the apex, narrowed at the base, serrulate, or the lower serrate, 7-17 cm. long, 1-4 

 cm. wide; heads commonly several or numerous, borne on slender, sometimes 

 roughish peduncles; involucre campanulate, its bracts lanceolate or ovate, acute or 

 acuminate, ciliolate, the tips of the outer ones spreading; chaff of the receptacle 

 oblong, entire, or 3-toothed; rays 5-10; disk yellow; achenes nearly glabrous; 

 pappus usually of 2 subulate awns. In moist woods and along streams, Penn. to 

 Ga., west to Ohio, Mo. and La. July-Sept. 



11. Helianthus giganteus L. Tall or Giant Sunflower. (I. F. f. 

 3907.) Perennial by fleshy roots and creeping rootstocks; stems hispid or scabrous, 

 at least above, 1-3.5 m. high. Leaves sessile or short-petioled, firm, serrate or 

 denticulate, acuminate at the apex, narrowed at the base, 5-15 cm. long, 1-2.5 cm - 

 wide; heads usually several, mostly long-peduncled, 4-6 cm. broad; involucre hemi- 

 spheric, its bracts squarrose. lanceolate-subulate, hirsute or ciliate, commonly as 

 long as the diameter of the disk; chaff of the receptacle oblong-linear, acute; 

 achenes oblong, glabrous; rays 10-20 ; pappus of 2 subulate awns. In swamps 

 and wet meadows, Me. and Ont. to the N. W. Terr., south to Fla., Neb. and La. 

 Stem commonly purple. Aug. -Oct. 



12. Helianthus ambiguus (T. & G.) Britton. Ambiguous Sunflower. 

 Stem slender, rough-hispid above, 5-8 dm. high, simple or little branched. Leaves 

 thin, lanceolate, sharply serrate, long-acuminate, 6-10 cm. long, finely rough- 

 pubescent on both sides, broadest just above the obtuse or subacute base, the upper 

 sessile, the lower short-petioled; heads few, 7-8 cm. broad; bracts of the involucre 

 lanceolate, acuminate, densely ciliate. In moist soil, L. I. and Ga. July-Sept. 

 \H. giganteus ambiguus T. & G.] 



13. Helianthus Maximiliani Schrad. Maximilian's Sunflower. (I. F. 

 f. 3908.) Perennial by fleshy roots and thickened rootstocks; stems stout, scabrous 

 or hispid below, 1-4 m. high. Leaves folding in drying, rigid, acuminate or 

 acute at both ends, denticulate or entire, 7-17 cm. long, 1-4 cm. wide; heads few 

 or numerous, 5-7 cm. broad, on stout densely rough-pubescent peduncles; involucre 

 hemispheric, its bracts lanceolate, acuminate, squarrose, densely strigose-pubescent, 

 often 18 mm. long; rays 15-30; chaff linear, acute, pubescent above; achenes 

 linear-oblong, glabrous or nearly so; pappus commonly of 2 lanceolate awns. On 

 dry prairies. Minn, and Manitoba to the N. W. Terr., Neb. and Tex. Aug.-Oct. 



14. Helianthus Dalyi Britton. Judge Daly's Sunflower. Perennial by a 

 fusiform tuber, 3-4 cm. long. Stem slender, simple, roughish, appressed-pubes- 

 cent, about 6 dm. high; leaves firm, conduplicate, drooping, finely rough-pubes- 

 cent on both sides, narrowly lanceolate, acuminate at both ends, distantly serrate 

 with low teeth, the larger about 1 dm. long and 1.4 cm. wide, all opposite or the 

 uppermost alternate; heads usually solitary and long-peduncled, rarely 2, about 

 8 cm. broad; involucral bracts narrowly lanceolate with long subulate tips; rays 

 acute; pappus 2 subulate awns; chaff of the receptacle pubescent at the acute apex. 

 Sag Harbor, N. Y. 



15. Helianthus subtuberosus Bourgeau. Indian Potato. Fleshy roots thick 

 and edible. Leaves thick, more or less serrate, all or all but the upper distinctly 

 petioled, sometimes all opposite, 6-12 cm. long, acuminate at the apex, mostly 

 narrowed at the base, the petioles ciliate; heads not very numerous; bracts of the 

 involucre lanceolate, acuminate, densely pubescent and white-ciliate, about 1.5 cm. 

 long; rays 3-4 cm. long. Mich, and Minn, to the N. W. Terr., Wyo. and Mont. 

 Aug. -Sept. [//. giganteus subtuberosus Britton.] 



16. Helianthus Rydbergi Britton, n. sp. Rydberg's Sunflower. Peren- 

 nial by a narrowly fusiform tuberous root with several stout branches. Stem 0.7- 

 1.5 m. high, somewhat branched near the summit; leaves ovate-lanceolate or the 



