Shrubs or subshrubs, glabrous or pilose with rigid stems. Sturdy spines present in leaf axils. Leaves simple to palmatisect to pinnate, petiolate or sessile. Verticillasters clearly distant, 2-6-flowered, in axils of upper leaves. Calyx tubular-campanulate, 5-10-nerved, not or scarcely bilabiate; lobes 5 (in ours) prominent, oblong or oblanceolate, subequal, as long as or longer than tube, erect-spreading. Corolla bilabiate, white or yellowish white; tube densely pilose-annulate at base; upper lip straight, densely villous; lower lip 3-lobed, median larger than laterals. Stamens 4, included or somewhat exserted, didynamous, anterior longer; thecae bilocular, diverging, hairy or glabrous. Style with 2 equal lobes. Nutlets sharply trigonous, obovoid, truncate at apex.