This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Tall stout erect perennial herbs, with verticillate or opposite leaves, and small minutely bracted white or blue flowers, in dense peduncled spike-like racemes, terminal, or in the upper axils. Calyx 4-parted, short. Corolla tubular, or salverform, nearly regular, 4-lobed, the tube cylindric, longer than the lobes. Stamens 2, exserted, inserted low down on the corolla-tube; filaments filiform; anthers obtuse, short. Style about as long as the stamens, stigma minute. Capsule narrowly ovoid, scarcely compressed, not emarginate nor obcordate, 4-valved at the apex. Seeds numerous, oval, minutely reticulated. [Greek, slender stamens, referring to the filaments.]
Two species, the following typical one native of eastern North America, the other of northeastern Asia.
Veronica virginica L. Sp. Pl. 9. 1753. Leptandra virginica Nutt. Gen. 1: 7. 1818.
Stem glabrous, or very nearly so, simple, strict, 2°-7° high. Leaves verticillate in 3's-q's or some of the uppermost opposite, lanceolate or oblong-lanceolate, short-petioled, long-acuminate at the apex, sharply serrulate, narrowed at the base, pinnately veined, glabrous both sides, or pubescent beneath, 3'-6' long, 1/2' - 1' wide; spikelike racemes several or rarely solitary, 3' - 9' long, very dense, the terminal one first developing; pedicels and bractlets about as long as the calyx; calyx-segments ovate-lanceolate, acute; corolla tubular, white or bluish, 2" long; capsule ovoid-oblong, 1"- 1 1/2" long, 2-3 times as long as the calyx.
In meadows, moist woods and thickets, Ontario to Manitoba, Massachusetts, Alabama and Texas. Recorded from Nova Scotia. Ascends to 2700 ft. in Virginia. Black-root. Culver's-physic. Brinton's-root. Oxadaddy. Quitch. Tall speedwell. June-Sept.