Body rounded. Tubercles large, swollen on one side, woolly at the base. Spines to 2 cm long, spreading, yellowish brown. Flowers pink or white with red throat.
The other species with rounded bodies, notably C. poselgeriana (A. Dietr.) Britton & Rose, C. radians (DC.) Britton & Rose and C. cornifera (DC.) Lem. are keyed out in the key; C. bumamma (Ehrenb.) Britton & Rose is occasionally grown and closely resembles C. elephantidens except for its smaller pale yellow flowers. The small flowered C. odorata Boed. which has all the central spines hooked possibly sufficiently different to be regarded as a distinct genus.
Source: (1997). Cactaceae. In: . Horticultural Flora of South-eastern Australia. Volume 2. Flowering plants. Dicotyledons. Part 1. The identification of garden and cultivated plants. University of New South Wales Press.