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..
Annual or perennial herbs, similar to Stachys. Lower leaves very long-petioled. Verticils many-flowered, in terminal spikes. Calyx nearly equally 5-toothed, 5-10-nerved. Corolla purple, the tube exceeding the calyx, the limb strongly 2-lipped; upper lip concave; lower 3-cleft, spreading. Stamens and pistil as in Stachys, but the anther-sacs parallel in some species. Nutlets ovoid, rounded above. [The classical Latin name of wood betony.]
Ten species, or more, natives of Europe and Asia, the following typical.
Betonica officinalis L. Sp. Pl. 573. 1753.
Stachys Betonica Benth. Lab. Gen. & Sp. 532. 1834.
Perennial, pilose or glabrate, deep green; stem slender, erect, usually simple, 1°-3° tall. Leaves oblong or ovate, obtuse at the apex, crenate all around, firm, cordate or truncate at the base, the basal and lower ones very long-petioled, the blades 3'-6' long, the upper distant, short-petioled or nearly sessile; lower petioles 1 1/2 -4 times as long as the blades; spike short, dense; bracts ovate, mucronate, about as long as the calyx; calyx-teeth acicular, half as long as the tube or more; corolla-tube exserted.