This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Helianthus annuus L. Sp. Pl. 904. 1753.
Helianthus lenticularis Dougl. Bot. Reg. pl. 1265. 1829.
Stem hispid or scabrous, stout, branched above, 3°- 6° high, or in cultivated races sometimes 15° high. Leaves all but the lower alternate, broadly ovate, petioled, 3-nerved, dentate or denticulate, acute at the apex, rough on both sides, sometimes pubescent beneath, the lower cordate at the base, 3'-12' long; heads in the wild plant 3'- 6' broad; disk dark purple or brown, 10"- 2' broad; involucre depressed, its bracts ovate to ovate-lanceolate, usually long-acuminate or aristate, hispid-ciliate; chaff of the flat receptacle 3-cleft; achenes obovate-oblong, appressed-pubescent, or nearly glabrous.
On prairies, etc., Minnesota to North Dakota, Idaho, Missouri, Texas and California. Recorded north to Saskatchewan. Much larger in cultivation; an occasional escape in the east. Gold. Golden. Larea-bell. Comb-flower. Its flowers yield honey and a yellow dye; its leaves fodder; its seeds, an oil and food; and its stalks a textile fibre. July-Sept.
Annual, similar to the preceding species, but smaller and with smaller heads; stem strigose-hispid or hirsute, 1°-3° high. Leaves all but the lowest alternate, petioled, oblong, ovate, or ovate-lanceolate, rough on both sides, usually paler beneath than above, sometimes canescent beneath, l'-3' long, entire, or denticulate, obtuse or acutish at the apex, mostly narrowed at the base; heads 1 1/2'-3' broad; disk brown, mostly less than 10" broad; involucre depressed-hemispheric, its bracts lanceolate or oblong-lanceolate, densely canescent, sometimes hispid-ciliate, acute or short-acuminate; achenes villous-pubescent, at least when young.
On dry prairies, Minnesota to Saskatchewan, Oregon, Iowa, Missouri, Texas and California. Found rarely in waste places farther east. Races differ in leaf-form, size and pubescence. June-Sept.
Helianthus angustifolius L. Sp. Pl. 906. 1753.
Perennial by slender rootstocks; stems branched above, or simple, slender, rough or roughish above, often hirsute below, 2°- 7° high. Leaves firm, entire, sessile, linear, slightly scabrous, rarely somewhat canescent beneath, 2'-7' long, 2"- 3" wide, the margins revolute when dry, the upper ones all alternate, the lower opposite; heads usually few, sometimes solitary, 2'-3' broad; involucre hemispheric, its bracts linear-lanceolate, acute or acuminate, scarcely squarrose, pubescent; receptacle slightly convex; disk purple; chaff entire or 3-toothed; rays 12-20; achenes truncate, glabrous; pappus usually of 2 short awns.
In swamps, Long Island, N. Y., to Florida, Kentucky and Texas, mainly near the coast. Aug.-Oct.