Verbena simplex aka Narrow Leaf Vervain

Verbena simplex is native to eastern and central North America, from Ontario and Québec in Canada south through the eastern and central United States to Florida and Texas, and west to Nebraska, with a fringe of populations into northwestern Mexico. POWO lists native occurrences in more than 30 U.S. states plus Ontario and Québec. It is widespread across the core of this range but rare and in decline in New England, where Native Plant Trust notes that "perhaps a tenth of the recorded locations still harbor the plant."

Per POWO, Verbena simplex grows primarily in the temperate biome, consistent with its distribution across temperate eastern and central North America from southern Canada to the southern United States and into northwestern Mexico.

Flowers are small (4–6 mm long), trumpet-shaped and five-lobed, ranging from deep lavender and purple to occasionally white or bluish. They are bilabiate with four didynamous stamens, and the corolla sits just above a 2–5 mm calyx with scattered hairs at the mouth. The inflorescence is a cluster of one to three slender, pencil-like spikes, 4–25 cm long, that elongate and stay densely covered with flowers as the bloom progresses.

Plants of the World Online recognises two infraspecific taxa: Verbena simplex var. simplex and Verbena simplex var. orcuttiana. The name Verbena simplex var. eggertii has historically been used and appears in synonymy. The species is most easily confused with other narrow-leaved vervains: Go Botany distinguishes it from V. hispida by its narrower leaves and longer spikes, and from V. stricta by its sparser stem hairs and narrower leaves.

Narrow-leaf vervain grows wild in open, dry habitats with sparse vegetation, including fields, prairies, sandplains, road cuts, ridges, ledges, gravel roadsides and pastures. It is particularly associated with calcareous soils where limestone is exposed or close to the surface, and it tolerates disturbed sites well. As an outdoor plant it suits sunny, lean, well-drained spots and is at home in temperate climates.

Wikipedia notes that Verbena simplex is attractive to bees and skippers, and probably also other butterflies, which visit the small lavender to purple flowers along the slender spikes.

New growth will sprout from the top of the Narrow Leaf Vervain as it grows vertically.

Narrow Leaf Vervain should be watered regularly, allowing the soil to dry out between waterings.

Narrow Leaf Vervain loves a well-draining soil. Perlite and vermiculite help with drainage, while coco coir adds organic matter, so a good potting soil mix will have all three. You can improve store-bought soil by adding some perlite to it.

Narrow Leaf Vervain requires abundant, bright, and direct light to thrive. The best placement for this plant is within one foot of a window to ensure it receives enough light. If you live in an area with more extreme weather, such as hot summers or cold winters, you may need to adjust the placement of the plant accordingly. During hot summer months, it is important to place the plant away from full sun, as this can cause the leaves to yellow or burn. During cold winter months, it is best to move the plant closer to the window to take advantage of the extra light that can help it survive. By keeping an eye on the current weather in your area, you can make sure your Narrowleaf Vervain is always in the right place to thrive.

The Narrow Leaf Vervain should be repotted when it has doubled in size or annually, whichever comes first. Providing fresh potting soil with all the essential nutrients each year ensures the plant's well-being, eliminating the need for fertilizer. Remember, plants derive their energy from the sun and not fertilizer.

Ploi lacks confirmed information on the toxicity of this plant. If you, a relative, or your pet accidentally consume plant material with unknown toxicity, it's best to consult a medical expert.