An erect, up to 90 cm, perennial shrublet with succulent, 4-angled or deeply 4-furrowed, white pubescent twigs. Leaves almost glabrous, subsessile or with up to 8 cm long, winged petiole; lamina of lower leaves on sterile shoots elliptic-oblong, 25-30 x 6-8 cm, long acuminate, lamina of flowering shoot leaves ovate or ovate-lanceolate, 3-7.5 x 2.5-3 cm, crenate to sharply serrate. Flowers blue to dark blackish-blue, 2.5-3 cm across, solitary or paired, in interrupted leafy, up to 15 cm long spikes; bracts foliaceous, up to 2.5 cm persistent; bracteoles linear-oblong, hairy. Calyx 5-lobed to the base, c. 1.2 long, lobes linear-oblong, c. 8-10 mm long, ± obtuse, patently glandular-hairy, slightly enlarged in fruit. Corolla 2.5-4.5 cm long, glabrous externally, tube pale to nearly white, cylindrical below, curved above, hairy within, limb lobes subequal, obtuse. Filaments hairy, anthers muticous at base. Style tips recurved. Capsule oblong, 1.6-1.8 cm long, 4-seeded, glabrous. Seeds c. 3 mm hairy.