9a. Helianthus petiolaris Nuttall subsp. petiolaris
Helianthus couplandii B. Boivin
Stems usually hispidulous to strig-illose, rarely ± hirsute to glabrate . Leaves: abaxial faces sparsely, if at all, gland-dotted. Peduncles usually bractless. Phyllaries 3–5 mm wide. Disc corollas: throats abruptly narrowed distal to dense-ly hairy basal bulbs. 2n = 34.
Flowering early summer–fall. Dry open areas, usually sandy soils; 10–1500(–2000) m; Alta., Man., Ont., Sask.; Ariz., Ark., Calif., Colo., Conn., Del., D.C., Idaho, Ill., Ind., Iowa, Kans., La., Maine, Mass., Mich., Minn., Mo., Mont., Nebr., Nev., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., S.C., S.Dak., Tenn., Tex., Utah, Va., Wash., W.Va., Wis., Wyo.
Subsp. petiolaris is native to western North America and adventive elsewhere (e.g., introduced in Ontario). Hybrids with with H. annuus and H. debilis have been reported.
