Perennial herb 40 cm - 1.5 m tall Stem: erect, branching above, rough-hairy. Leaves: opposite, stalked, 4 - 18 cm long, more than 2 cm wide, lance-shaped to narrow egg-shaped, gradually tapering to a pointed tip, coarsely toothed or cut, often lobed near base, hairless or rough hairy on both surfaces. Inflorescence: a terminal cluster of many upright, pencil-like spikes less than 7 mm across. Flowers: overlapping on the spike, with lance-awl-shaped bracts often a little shorter than the calyx, a 2.5 - 3 mm long calyx with hairs and awl-shaped lobes, and a hairy bluish purple corolla usually longer than the calyx. Fruit: four linear nutlets surrounded by incurving awl-shaped calyx lobes, each nutlet 1.5 - 2 mm long and smooth to faintly grooved.
Similar species: Verbena urticifolia and Verbena hastata have more than three flower spikes in a cluster. Verbena urticifolia is distinguished by its egg-shaped leaves and its white flowers that are well separated along the spike.
Flowering: late June to mid September
Habitat and ecology: Frequent in marshy areas, moist meadows, wet woods, and wet prairies.
Occurence in the Chicago region: native
Etymology: Verbena is the Latin name for vervain. Hastata means spear-shaped.
Perennial; stems 4-15 dm, branched above, rough-hairy, with short, spreading or antrorse hairs; lvs lanceolate to lance-oblong or lance-ovate, 4-18 cm, gradually acuminate, petiolate, coarsely serrate or incised, often hastately 3-lobed at base, glabrous or strigillose on both sides; spikes strict, usually many in a terminal panicle, short and compact, thicker than in no. 5 [Verbena urticifolia L.]; bracts lance-subulate, commonly a little shorter than the cal; cal 2.5-3 mm, hairy, with ±connivent, shortly subulate-tipped lobes; cor usually blue, the tube somewhat longer than the cal, hairy, the limb 2.5-4.5 mm wide; nutlets linear, 1.5-2 mm, faintly striate or smooth; 2n=14. Moist fields, meadows, prairies, and swamps; N.S. to B.C., s. to Fla. and Ariz. June- Oct. A hybrid with V. simplex is V. آlanchardii Moldenke; one with V. stricta is V. زydbergii Moldenke.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.