Strigose perennial from a woody taproot, 0.5-4 dm; lvs wholly cauline, the lowest often reduced, the others linear-oblong to narrowly lanceolate or linear, rather numerous, 2-6 cm נ2-6 mm; well developed fls crowded in the uppermost axils, short-pedicellate; cor bright yellow, salverform, the tube 1.5-3.5(-4) cm, the limb 1-1.5(-2) cm wide, with erose or almost fimbriate lobes, these fls long-styled and mostly sterile; cleistogamous, highly fertile, short-styled fls commonly developed later farther down the stem, the plant becoming slenderly much-branched; nutlets ivory-white, shining, sparsely pitted; 2n=24, 36. Dry plains and barrens; s. Ont. to Man. and Wis., w. to B.C., Utah, s. Nev., and n. Mex. Apr., May. (L. angustifolium; L. linearifolium)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.