Vervain Family (Verbenaceæ)
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.