Shrubs or subshrubs, rarely perennial herbs or lianas. Stems terete to subquadrangular, glabrous or pilose. Leaves sessile or petiolate; blades lanceolate to narrowly elliptic to elliptic or oblong to ovate, acuminate to cuspidate apically, cuneate to narrowly rounded or auriculate basally, margins entire to crenate or undulate, glabrous or with a few trichomes along primary vein of lower surface, scabrous or pilose. Inflorescences terminal or rarely axillary spike-like racemes, panicles or dense thyrses with few to many flowers per fascicle; rachis glabrous or pilose, sometimes glandular puberulent; bracts lanceolate to narrowly triangular or subulate; bracteoles narrowly triangular to subulate; calyx lobes 5, narrowly triangular or subulate, glabrous to pubescent, margins sometimes ciliolate; corolla red, sometimes yellow, infrequently white, lilac, violet or pink, subregular to weakly 2-lipped, tubular, glabrous or densely pubescent to glandular puberulent without, upper 2 lobes elliptic to narrowly oblong or ovate, rounded or suborbicular, lower 3 lobes oblong to elliptic, ovate to oval or orbicular, sometimes with ciliolate tips; stamens 2, included or exserted due to heterostyly, filaments glabrous or pubescent at least basally, anthers 2-thecous, thecae parallel, lacking basal appendages, glabrous, rarely pubescent, staminodes 2; ovary mostly glabrous, rarely pubescent. Capsules clavate, retinacula present, septa with retinacula remaining attached to inner wall of mature capsule; seeds mostly 4, homomorphic, lenticular, lacking trichomes.
More
Herbs or shrubs. Leaves often large with the cystoliths visible on both the surfaces, sessile to petiolate. Inflorescences in terminal panicles or thyrses with inconspicuous bracts. Flowers white, red or yellow, 5-merous; calyx with equal, subulate segments; corolla bilabiate, the upper lip 2-lobed, the lower 3-lobed; stamens 2, exserted or extending to the mouth, the anthers 2-celled with the cells parallel and blunt at the base, staminodes 2. Capsules clavate, bearing 4 seeds.