Found in dry grounds, waysides and fields, in July and August.

The large stalk, from 4 to 6 feet in height, is 4-angled and grooved down the sides; it is stout, roughish, and green.

The short-stemmed leaf is long, narrow, and tapering, with a sharply toothed margin, a strongly curved midrib, and a coarse texture, with a roughish surface; in color dark green. The lower leaves are more or less 3-cleft. The arrangement is opposite.

The small tubular corolla is 5-parted, and colored a rich dark blue-purple; the green of the calyx is also tinged with purple. The flowers grow in slender spires, which are grouped in an open pyramidal cluster on the top of the stalk.

The flowers at the foot of the cluster open first, only a few at a time; as the flowering continues upward there is left behind an ever-lengthening line of purple tinged calices which add greatly to the beauty of the bloom, and supply the unifying color in the general scheme of purple and green. Seen in masses, illumined by the sunlight, the color is rarely dark and rich. The bumble bee is a devoted friend to the Vervain, and may often be seen in the early evening, sleepily clinging to the flowery spire he has chosen for his night’s lodging.