Solitary, body spherical to 5 cm wide, crown depressed or flat, tap root absent. Tubercles prominent. Axils slightly woolly. Central spines (0-)1-6, 3-7 mm long, dark reddish brown. Radial spines 33-36, 3-6 mm long, yellowish or whitish. Flowers pinkish with darker central stripe, 5 cm wide and 2 cm long. Fruit pale green.
Distinguished from M. dodsonii Bravo [M. deherdtiana var. dodsonii Bravo] by lower tubercle spiral count (5-8 cf. 8-13) and spination-central spines 3-5, 10-20 mm long brownish, radial spines 20-21, 10-18 mm long, whitish; also flowers a deeper rose-violet.
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.