Shrubs or subshrubs, unarmed, glabrous or hairy. Leaves opposite
or whorled, entire or more or less crenate. Flowers sessile, in subterminal spikes,
yellow or red, showy. Bracts 4-ranked, large, ovate-lanceolate, bracteoles
linear-lanceolate. shorter than the calyx. Calyx and corolla deeply 5-lobed,
lobes subequal. Stamens 4, didynamous, all fertile, included in the tube,
anther 1-celled. Ovary 4-ovuled. Capsules oblong, 4-seeded, flattened, more or
less quadrangular. Seeds ellipsoid-ovate, with fringed scales or hairs.