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.
Rather frequent in the lake area in marshes and springy areas about lakes and along streams. Farther south it is infrequent to local in springy places. It is sometimes found in wet prairies.