Perennial, prostrate, branched herb, villous or hirsute; leaves opposite, sometimes whorled below, usually alternate above, ovate or hastate; petiole very short; pedicels rigid, often exceeding the leaves; flowers axillary, raceme or spicate; bracteate-bracteolate; calyx segments-5, imbricate, lanceolate; corolla tube spurred in front, spur straight or slightly curved forward, much shorter than hairy corolla tube; upper lip erect, 2-lobed, lower spreading, 3-lobed, palate purple spotted; stamens 4, didynamous, ascending, included; anther cells 2, parallel, distinct; ovary 2 celled, style filiform, stigma minute; capsule ovoid or globose, often lobed, lobes unequal, opening by an apical pore; seeds numerous, closely and roughly pitted.