The flowers of Xysmalobium undulatum var. undulatum grow in umbel-shaped clusters from leaf axils near stem tips. The peduncle of the umbel is sturdy and yellow-green, the pedicels of individual flowers thin. The sepals are acutely pointed, olive green in colour. The five petals curve upwards abruptly to form a wide cup; their obtusely pointed tips curving back and are very hairy. The petals are greenish and covered in whitish hairs, the corolla cup from 1 cm to 1,5 cm in diameter. The five corona lobes at the base of the corolla cup are broad, positioned around the anthers and the erect staminal column in the centre.
The inflated-looking fruit is large and ovoid in shape with soft, cream coloured or sometimes pinkish bristles that tend to curl, sometimes growing on longitudinal ridges along its surface.
These flowers were photographed in January, summer being the blooming season (iSpot; Van Wyk and Malan, 1997; www.plantzafrica.com).