Erect annual. Stems 30-40 cm, quadrangular, with long spreading eglandular multicellular hispid hairs. Leaves 3-6 x 16-3 cm, ovate to ovate elliptic, serrate, cuneate, acute, with long scattered eglandular hairs on both surfaces, gland-dotted below or not; petiole up to 2 cm. Verticillasters up to 20-flowered, 2-5, distant below, approximating above. Bracts to c. 10 mm, narrow linear-lanceolate, subulate. Calyx 8-12 mm with spreading eglandular and glandular hairs; teeth subequal with subulate spines up to 3 mm. Corolla white or yellowish, 8-12 mm; tube slender, 6-8 mm; middle lobe of lower lip streaked purple, longer than laterals, emarginate or entire. Nutlets c. 3 x 2 mm, ovoid, slightly compressed, apically rounded, not mucilaginous on wetting.