The flower of Stapelia grandiflora var. grandiflora reaches a diameter of 15 cm. One to three flowers may develop from near the stem base on 2 cm long velvety pedicels. The buds bulge beyond cone shape with five flattish surfaces between dark ridges where the corolla lobes are still attached to each other. The sepals are lanceolate and hairy.
The colour of the open flowers is dark purplish brown near the five tapering corolla tips. The middle sections of the almost oblong, just slightly bulging corolla lobes are pale purplish red, creamy near the margins where they meet. There are closely spaced, shiny transversal ridges on the corolla surface. Long whitish hairs, many pointing inwards, give the (ciliate) corolla margins a fluffy appearance. On the corolla surface there are erect, purple hairs, but not near the tips where the surfaces are hairless.
The outer corona (in the centre of the corolla) is dark purplish brown with five pointed or rounded lobes, concave towards the base where its colour is pale yellow. Inside this is also a tiny, dark purple or brown inner corona with five lobes (White and Sloane, 1937).