Cal 15-nerved, slightly oblique at the throat, unequally 5-toothed, the midnerve of each tooth excurrent into a short awn; cor 2-lipped, the upper lip somewhat concave, 2-lobed, the lower lip spreading, with a large central lobe and smaller lateral ones; stamens 4, the upper pair the longer, normally ascending under the upper lip and scarcely exserted; pollen-sacs set end to end along one side of the filament just below its summit (which commonly surpasses the upper pollen- sac), divergent at a wide angle; opening by separate slits; creeping perennials with long- petioled, rotund or reniform lvs and small or medium-sized, short-pediceled, blue fls usually 3 per axil. 10, temp. Eurasia.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
