Verbena stricta Vent.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Perennial; stems 2–12 dm, subterete, rather densely pale-hairy; lvs ovate, elliptic, or suborbicular, 3–10 × 1.5–5 cm, sessile or nearly so, thick, sharply serrate to incised, hirsute and rugose above, densely hirsute-villous and veiny beneath; spikes solitary or several, long, thick, remaining compact; bracts lance-subulate, about equaling the cal, hirsute, ciliate; cal 4–5 mm, densely hirsute, its lobes acuminate; cor mostly deep blue or purple, the tube a little exserted, hairy, the limb 7–9 mm wide; nutlets ellipsoid, 2–3 mm, raised-reticulate above, strongly striate below; 2n=14. Prairies, barrens, fields, and roadsides; Ont. and O. to N.D. and Wyo., s. to Tex. and N.M., and intr. into e. U.S. from Mass. to Del. and W.Va. June–Sept.