General: Perennial herb from slender or somewhat thickened rhizome; stems erect, slender, 10-30 cm tall, clustered or branched near base, 4-angled, with stiff upward-pointing hairs but sometimes nearly glabrous or hairs longer, spreading, and gland-tipped.
Leaves: Opposite, lance-elliptic to oblong or nearly egg-shaped, 1.5-2.5 (3.5) cm long, 3-10 (16) mm wide, often 3- to 5-veined from near the base, tips blunt or rounded, usually entire; short-stalked or the upper almost unstalked; lower often broader and longer-stalked than others, often somewhat toothed, but commonly deciduous; hairiness similar to that on stems, or looser.
Flowers: Inflorescence of solitary flowers in axils of slightly reduced leaves; corollas tubular, deep blue-violet, 20-30 mm long, throat open, 2-lipped, the upper lip entire, shorter than lower and hood-like, the lower lip somewhat spreading, 3-lobed and with long, flattened, white hairs on the broad central lobe; calyces 3.5-5.5 mm long, 2-lipped, upper lip with a scooped-out ridge across the back.