Much branched woody shrub up to c. 1.5 (-2) m. Stems leafy, sulcate, finely puberulous. Leaves usually in clusters at nodes, obovate, cuneate, c. 8-15 x 5-12 mm, thick-textured, entire or with 2-3 small apical mucronate teeth, with short ± adpressed eglandular hairs and numerous punctate oil globules. Petiole subabsent to c. 3 mm. Spines 10-15 mm, sturdy. Verticifasters 4-6-flowered in upper leaf axils, remote. Calyx bilabiate, 10-12 mm long, tubular-campanulate, finely pubescent; tube prominently 10-sulcate-ribbed; lobes oblong to oblong-lanceolate becoming straw-coloured in fruit, somewhat longer than tube, apiculate, spreading-erect. Corolla white c. 12 mm; tube included within calyx tube; upper lip ± straight, densely villous, bearded at margins. Nutlets (immature) apically pilose.