Sprawling to erect perennial herbs with cystoliths, pilose or glabrate. Leaves petiolate; blades thin, margin entire, crenate, or repand-dentate. Inflorescences terminal or axillary spikes; bracts opposite, green, imbricate, usually ovate to suborbicular, margin entire, ciliate. Flowers sessile, subtended by 2narrowly lanceolate to elliptic bracteolesCalyx deeply 5-lobed, lobes linear-subulate, ciliolate, slightly unequal in length; corolla usually lavender, white, or purplish, tube slender, straight or curved, somewhat enlarged above, limb subregular, and ± equally 5-lobed to subbipped with upper lip 2-lobed and lower lip 3-lobed, corolla lobes contorted in bud; stamens 4, didynamous, inserted above middle of corolla tube, filaments united at base by a membrane, anthers 2-thecous, thecae equal, parallel, muticous at base, staminodes 0; ovules few to 6 in each locule, style included in corolla tube, subulate at apex, posterior lobe usually minute. Capsules substipitate, ellipsoidal, retinacula present, septae with retinacula remaining attached to inner wall of mature capsule; seeds 8-16, flat, lenticular, margins covered with hygroscopictrichomes.