Annuals. Stems branched, erect, with an indumentum of simple hairs. Leaves undivided, petiolate or sessile, crenate or serrate. Inflorescence of dense axillary and terminal ovoid or oblong heads; verticillasters many-flowered. Bracts large, hidden within heads, subtending several flowers, imbricate. Flowers white to pink, very small. Calyx tubular-campanulate, bilabiate, 7-10-nerved, apparently with one large entire upper lobe and 4 lower teeth; tube glabrous at throat; calyx enlarging in fruit, flattened above with converging lips. Corolla scarcely bilabiate, subequally 5-lobed, slightly or not longer than calyx. Stamens 4, inconspicuously declinate; thecae glabrous unilocular. Nutlets very small, smooth or finely papillate.