The large flower of Rothmannia capensis is bell-shaped, borne erectly. A flower is about 8 cm long. There is a broad corolla tube before the five petal lobes spread and sometimes recurve, their tips attenuating abruptly.

Flower colour is white, fading to cream with maroon streaks and speckles in the throat. The five stamens arise in the corolla mouth, partly exserted. Their anthers are sessile and linear, visible in the photo at the flower mouth between the corolla lobes. They curve down here, probably just lying upon the corolla in their final stage, as they are sometimes erect, maybe when still functional. The style is erect and exserted above the mouth of the corolla.

Flowering happens in summer, the flowers retaining their sweet fragrance for long, even when dry (Coates Palgrave, 2002; Van Wyk and Van Wyk, 1997).