Soft-stemmed shrub up to 4 m. tall, trunk swollen at the base, up to 1 m. in diam., from which arise several thick, erect main branches which taper rapidly; bark grey or mottled with yellow; branches stiff, sparingly branched, spiny; spines spreading to recurved, 5–10 mm., leaves deciduous, oblong to obovate, 1–2.5 cm. long, 4–6 mm. broad, obtuse to retuse at the apex, cuneate at the base, grey, semi-coriaceous, densely covered with stellately-branched mucilage glands; midrib distinct below, impressed above. Flowers large, sweet-scented, 1–3 in short raceme-like inflorescences on short shoots which are sometimes elongated; pedicels 4 mm. long. Calyx 5-partite, 4 mm. long. Corolla sparingly tomentose, with a long, cylindrical, only slightly curved tube, 8–10 cm. long, 4–6 mm. in diam., produced near the base into a short blunt spur, 1–1.5 cm. long, cream-coloured, sometimes suffused with purple; limb spreading at first, later reflexed, 4–5 cm. in diam., slightly oblique; lobes 5, subcircular, 1.6–2 cm. broad. Stamens 4, subequal, inserted near the throat of the corolla tube; filaments 4–5 mm. long. Ovary, oblong, 7–8 mm. long, laterally compressed, bilocular, each loculus divided by an incomplete false septum; ovules many, uniseriate in each compartment. Style slender, equaling the corolla tube; stigma reaching the corolla mouth or exerted by up to 10 mm., broadly bilobed. Fruit a rigid woody capsule, obovate in outline, often retuse at the apex, 4–6 cm. long, 3.5–5 cm. broad, laterally compressed, greyish brown. Seeds flat, transversely oblong, winged, about 1.5 cm. long and 2.5 cm. broad (incl. wings).