V. hastata grows as a stiffly erect stem, occasionally branching in the upper half, reaching up to 1.5 m (5 ft) tall.

[6] The inflorescence is a panicle, or group, of flowering spikes, up to 30 cm (1 ft) long at the end of the upper stems.

[8] This species is a member of the diploid North American vervains which have 14 chromosomes altogether.

Hybridization seems to have played some role in its evolution, presumably between some member of a group including the white vervain (V. urticifolia), V. lasiostachys or V. menthifolia, and V. orcuttiana or a related species.

In Canada, it is native in the provinces of British Columbia, Saskatchewan, Manitoba, Ontario, Quebec, New Brunswick, Nova Scotia, and Prince Edward Island.