Verbena urticifolia L.
Habitat: Rich thickets and borders of woods. [Hardwood to mixed forest (forest, upland); Open wetland, not coastal nor rivershore (non-forested, wetland)]
Range: Southwestern Quebec and southern Maine to South Dakota, south to northern Florida and west to Texas. Not rare south of Maine. Possibly extirpated from the state.
Aids to Identification: White vervain is a tall (0.6-1.2 m) herbaceous plant with opposite, oval, toothed leaves tapering to a narrow point. The flowers are small with five petals and borne in a narrow terminal spike and smaller spikes from the leaf axils. Aside from the flower color, it resembles the more common blue vervain (V. hastata). Although, the flowers of white vervain are not as contiguous and overlapping on the spikes and the number of flower spikes is generally fewer. V. urticifolia also has smaller flowers than V. hastata (2 mm wide vs. 2.5-4.5 mm wide).
Ecological characteristics: Ecological relationships in Maine are not well known.
Phenology: Flowers June to September.
Synonyms: Maine populations are represented by var. urticifolia.
Known Distribution in Maine: This rare plant has been documented from a total of 5 town(s) in the following county(ies): York. This rare plant was recently observed (2013), but the other 4 occurrences are historical.
Reason(s) for rarity: At northern limit of range.
Conservation considerations: Unknown; no current locations for this species are documented.