Perennial with a sturdy rootstock, few-stemmed or forming clumps to 1 m across. Stems quadrangular, 20-120 cm, usually unbranched, lanate to pilose with irregularly rayed stellate hairs, above with sessile oil globules, leafy. Leaves broadly ovate to ovate-lanceolate, 15-45 x 15-40 mm, ± regularly crenate to crenate-serrate, greyish white below with irregularly rayed stellate hairs and usually sessile oil globules, greener above, broadly cuneate to subtruncate at base, apically ± rounded; petiole 15-20 mm. Verticillasters 8-12, in mils of upper leaves, dense, to 20-flowered, distant. Bracts subulate-spinulose, c. 8 mm. Calyx tubular, 10-ribbed thick-textured, ± densely covered with irregularly rayed stellate hairs and with some sessile oil globules; tube straight, 4-6 mm long, internally densely bearded at the throat, open in fruit; teeth (5-) to 10, subulate, with 5 longer 1.5-3 mm ones and 5 shorter 1.5 mm teeth, all horizontally spreading in fruit and apically curved to hooked. Corolla white or yellowish-white, stellate pilose, 8-10 mm; upper lip deeply bifid, straight; lower lip ± equal to upper; tube slender, pilose annulate within. Nutlets oblong, trigonous, c. 2 x 1.2 mm.