Erect, 3-10 dm from a short rhizome, usually with short branches from the upper nodes; lvs firm, usually ascending, linear, 3-8 cm נ2-7 mm, gradually tapering to the sessile base, the margins smooth and revolute or with a few cilia at the very base, the lateral veins obscure or obsolete; fls almost entirely in terminal clusters on the stem and branches; cal-lobes lanceolate, 4-6 mm; cor-lobes 7-12 נ5-9 mm; stamens distinct; staminodes triangular to subulate; 2n=34. Moist or wet soil, especially on prairies; Mass. to Ga., w. to Man. and Ark., chiefly n. of the Ohio R. and w. of the Appalachians, and in the Ozark region of Mo. July, Aug. (Steironema q.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.