Herbs with opposite leaves and perfect but usually irregular flowers, the tubular corollas spreading into two lips or four or five lobes.
Blue Vervain (Verbena Hastata) is our most common example of the genus. It is a tall, slender, rank-growing plant reaching heights of 2 to 7 feet. The leaves are dark green, short-stemmed, lanceolate, sharply toothed and grow oppositely on the stem.
At the top of the stem are numerous, slender flower spikes, each branching from the stem and assuming a vertical position, in a regular order suggestive of candelabra. These slender spikes contain many buds, the lower of which open first. From July until the end of August we will find rings of purple flowers about the spikes, gradually drawing nearer the ends as the flowering season advances, and leaving behind a long trail of purplish calyces. The tubular corolla has five spreading lobes, a slender pistil and two pairs of stamens. Blue Vervain, which is found throughout our range, was formerly, and is now to some extent, used for certain home medicinal remedies.
Blue Vervain. Verbena hastata.
White Vervain (Verbena Urticaefolia) is a similar but smaller and even more slender species found in thickets and waste ground. The flower spikes are very slender and the flowers much smaller than those of the last species, and they are white in color. The stem grows from 2 to 4 feet high, is erect, coarse, four-sided and grooved.
Verbena canadensis is quite different; it has an erect bristly-hairy stem from 6 to 18 inches tall and opposite, deeply lobed and toothed leaves. The lilac flowers, nearly an inch broad, are in short terminal clusters; the tubular corolla has five spreading, notched lobes. It grows in open woods and on prairies from Ind. to Dakota and southwards.