Plants small trees or deciduous shrubs; stems with grey bark; spines1.2–3.5 cm long,sharp, stout, straight, axillary, opposite-decussate. Leaves opposite or fascicled on dwarf branches, petiolate and stipulate; petioles short, hairy;stipules deltoid or broadly ovate, acuminate, ciliate on the margins; blades 2.5–7.5 x 1.25–3.75 cm,obovate, rarely ovate or spathulate, entire, obtuse or acute, membranous, lateral veins prominent, both surfaces glabrous or pubescent, pubescence most prominent over the veins on the lower surface. Inflorescences usually of solitary flowers, rarely 2–3 on a peduncle;peduncles 8 mm long, subterminal on dwarf leafy branchlets. Flowers2–2.5 cm across, yellowish or green-whitish-turning pale when old, fragrant, subsessile when pedunculate; calyces 1.25 cm long, strigose, tube campanulate, teeth usually ovate or rounded rarely spathulate, obtuse, spreading equalling the tube; corollas 1.25–2 cm in diameter, tube 5 mm long, densely silky hairy outside, lobes about 1.25 cm long, oblong or obovate, subacute, pubescent outside, spreading; stigmas fusiform. Fruits25–38 cm long, yellow-ovoid or subglohose, smooth or obscurely ribbed, crowned by large calyx-lobes; seeds numerous, embedded in pulp, flattened.
Catunanregam spinosa grows in Ceylon, India, Pakistan, and Africa. In the Flora of Pakistan, it is reported to grow from Rawalpindi eastward and East of Kashmir foothills.