Perennial herb 10 cm - 0.7 m tall Stem: erect with few ascending branches, usually sparsely hairy. Leaves: opposite, short-stalked to nearly stalkless, 3 - 10 cm long, 3 - 15 mm wide, linear to narrow-oblong or lance-shaped with a blunt to short-pointed tip and tapered base, toothed, wrinkled above, veiny beneath, hairless or sparsely hairy on both surfaces. Inflorescence: a cluster of one to three slender spikes, each pencil-like spike erect and usually densely covered with flowers. Flowers: deep lavender or purple, subtended by lance-awl-shaped bracts usually shorter than the calyx. The sparsely hairy calyx is 2 - 5 mm long, and the corolla is slightly longer than the calyx with scattered hairs at the mouth. Fruit: four linear nutlets surrounded by the persistent calyx, each nutlet 2 - 3 mm long with raised interconnecting veins above and longitudinal grooves toward the base.
Similar species: Verbena bracteata, Verbena simplex, and Verbena stricta have one to three flower spikes per cluster and blue to purple flowers. Verbena bracteata is identified by its decumbent to ascending stems, pinnately cut and often three-lobed leaves that are wider than 2 cm, and bracts that are longer than the calyx. Verbena stricta is distinguished by its densely hairy leaves and stem and its egg-shaped to oblong or nearly round leaves that are wider than 2 cm.
Flowering: late May to mid-September
Habitat and ecology: Locally frequent in open areas such as fields, prairies, and along gravel roads, often where limestone is exposed or near the surface.
Occurence in the Chicago region: native
Etymology: Verbena is the Latin name for vervain. Simplex means unbranched.
Author: The Morton Arboretum
From Flora of Indiana (1940) by Charles C. Deam
This species has been reported from 9 counties and doubtless is found infrequently throughout the state. It prefers dry and rather sandy soil in the open, although I have one specimen from a dried-up slough. It is generally found along roadsides and railroads, in fallow fields, and on open, washed, wooded slopes. It is usually found associated with Verbena stricta.
Perennial; stems chiefly erect, 1-7 dm, the few branches ascending, usually sparsely strigillose; lvs linear to narrowly oblong, lanceolate, or spatulate, 3-10 cm, to 1.5 cm wide, tapering to a short petiole or a subsessile base, obtuse or subacute, toothed, rugose above and veiny beneath, glabrate or sparsely strigillose; spikes slender, solitary on the stem and branches, usually rather dense; bracts lance-subulate, commonly shorter than the cal; mature cal 2(-5) mm, sparsely hairy, its lobes acuminate; cor deep lavender or purple, the tube scarcely longer than the cal, with scattered hairs at the mouth, the limb 4-6 mm wide; nutlets linear, 2-3 mm, raised-reticulate above, striate toward the base; 2n=14. Dry soil of woods, fields, rocky places and roadsides; Ont., Vt. and Mass. to Minn., s. to Fla. and Tex. June-Aug. (V. angustifolia Michx., not Mill.) A hybrid with V. stricta is V. حoechina Moldenke.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.