Plants perennial, glabrous; stems stout, 3-6 dm tall; leaves opposite, basal usually withered at flowering time, stem leaves narrowly lanceolate; inflorescence one-sided, narrow, not glandular; calyx lobes lanceolate, 4-8 mm long; corolla blue, purple, or violet-blue, 26-34 mm long, markedly expanded, 10-17 mm wide, base of lower lobes densely white-bearded; stamens completely dehiscent but not explanate; staminode glabrous, tip dilated. Flowers July and August.