A rambling shrub or high-climbing woody vine. Its thick stems are mostly hairless and bear slightly curved spines (5-15 mm long) in the leaf forks. Its alternately arranged leaves (4-13 cm long) are shortly stalked with entire margins and pointed tips. Its small flowers are arranged in three-flowered units, with each flower being subtended by a large purplish bract (2.5-5 cm long). These flowers have a greenish or purplish tube (9-20 mm long) with five small cream, yellowish or whitish 'petals' at the tip.