* Stems erect.
S. Betonica: stems 1-2 feet high, downy or hairy; leaves mostly radical, oblong, cordate at the base, coarsely crenate, the upper ones few, distant, sessile; flowers purple, in dense whorls, collected in a close terminal, oblong head or spike; the upper lip of the corolla ovate, erect, slightly concave. - Betony. - Woods and thickets. Fl. July, August. It is sometimes called Betonica.
S. sylvatica: stem stout, erect, branching, 2-4 feet high, coarsely hairy; leaves all stalked, cordate, ovate, crenate; flowers in distant whorls, forming long terminal spikes, dark reddish-purple, the lower lip variegated with white. - Shady banks, and edges of woods. Fl. July, August.
S. palustris: stems tall, stout, with short hairs; leaves oblong or lanceolate, slightly cordate at the base; flowers pale bluish-purple, forming shorter and more crowded spikes than in the last. - Ditches, and moist banks. Fl. August.
** Stems decumbent.
S. arvensis: annual; stems slender, hairy, branched, decumbent or slightly ascending; leaves small, ovate, scarcely cordate; flowers small, of a pale purple, in loose, leafy spikes. - Fields and waste places. Fl. July, August.