Perennial semi-succulent herb; stems erect to decumbent, 0,5 — 1,5 m tall, sparsely to densely tomentose. Leaves petiolate; blade medium- to thick-textured, ovate to subrotund, (35-)40-105 x (25-)30-100 mm, sparingly strigose to densely woolly-tomentose, gland-dotted, apex acute to rounded, base cuneate to subcordate, margin shallowly to fairly distinctly crenate-dentate; petiole 10—40 mm long. Inflore­scence terminal, simple or with 1 — 2 pairs of branches near the base, racemes 80—500 mm long; bracts usually early deciduous but sometimes persisting to the flowering stage (in var. tomentosus); flowers in sessile 4—15-flowered cymes, forming 8 — 25-flowered verticils; verticils 10—30 mm apart; pedicels 2—4 mm long. Calyx 5 mm long in fruit, glandular-scabrid, shape as in P. dinteri (no. 16). Corolla usually shades of mauve to purple, rarely white, 7—13 mm long, finely pubescent and gland-dotted on the lips; tube expanding gradually from the base and bent about the middle; lower lip boat-shaped, 4—7 mm long. Stamens free to the base, 5 — 8 mm long.