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..
Similar to the following species, but the stem usually roughish-pubescent above. Leaves short-petioled, ovate-lanceolate, or lanceolate, 3-nerved, green both sides, but darker above, generally rougher on the upper surface, the lower ones sharply serrate; branches and peduncles scabrous; heads several, 21/2'-31/2' broad; bracts of the hemispheric involucre linear-lanceolate, long-acuminate, ciliate and puberulent, longer than the yellow disk, sometimes foliaceous, and 3 times its length.
In dry soil, Connecticut to Pennsylvania, North Carolina, Ohio, Minnesota and Arkansas. Aug.-Sept.
Helianthus strumosus L. Sp. Pl. 905. 1753.
H. mollis Willd. Sp. Pl. 3: 2240. 1804. Not Lam. 1789.
H. tnacrophyllus Willd. Hort. Berol. pl. 70. 1806.
Perennial by branched, sometimes tuberous-thickened rootstocks; stem glabrous below, sometimes glaucous, 3°-7° high, branched above, the branches usually pubescent. Leaves short-petioled, ovate or ovate-lanceolate, rarely lanceolate, not membranous, rough above, pale and somewhat puberulent or ca-nescent beneath, serrate, serrulate, or nearly entire, acuminate, contracted much below the middle and decurrent on the petiole, 3-nerved above the base, 3'-8' long, 1'-2 1/2' wide, mostly opposite, the upper often alternate; heads commonly several, 21/2'-4' broad; involucre hemispheric, its bracts lanceolate or ovate-lanceolate, acuminate, ciliate, equalling or a little longer than the diameter of the yellow disk; rays 5-15; chaff pubescent; achenes nearly glabrous.
In dry woods and on banks, Maine and Ontario to Minnesota, Georgia, Tennessee and Arkansas. July-Sept. Races differ in leaf-form and texture. A hybrid with H. decapetalus has been described.
Helianthus hirsutus Raf. Ann. Nat. 14. 1820. Helianthus hirsutus trachyphyllus T. & G. Fl. N. A. 2: 329. 1842.
Perennial; stem densely hirsute, usually branched above, stout, rigid, 2°-4° high. Leaves ovate-lanceolate or the upper lanceolate, rounded, truncate or subcordate at the base, acuminate at the apex, thick, very rough above, rough-pubescent beneath, 3-nerved, serrate or serrulate, 3'-6' long, ¥-2' wide, short-petioled, or the uppermost sessile, nearly all opposite, the petioles of the lower ones 1/2'-3/4' long; heads usually several, 2'-31/2' broad; involucre hemispheric, its bracts lanceolate, or ovate-lanceolate, acuminate, ciliate, mostly puberulent, erect or somewhat spreading, equalling or shorter than the yellow disk; rays 12-15; chaff obtusish, pubescent at the summit; achenes oval, rounded at the summit, glabrous; pappus of 1 or 2 subulate awns.
In dry soil, Pennsylvania and Ohio to Wisconsin, Nebraska, West Virginia, Georgia and Texas. July-Oct.