Typically solitary, body globular 4-5 cm wide. Tubercles obscured, cylindrical. Axils slightly woolly. 1-2 whitish central spines, tips dark and hooked 5-6 mm long, 35-50 whitish radial spines 3-5 mm long. Flowers whitish or yellowish with a reddish central stripe, 1.5 cm long. Fruit ? [M. aguirrei undescribed]
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.