It is a simple plant with a globose and flattened stem that usually measures between 30 and 40 cm in diameter by 10 cm high, sometimes quite buried in the ground. It has 13 to 25 flattened and thickened ribs below the areolas, which are usually 3 to 4 cm apart from each other and are oval in shape, about 8 mm long by 6 mm wide. It has 6 to 8 radial spines, recurved and 1 to 2 cm long, red in color. Four central spines, somewhat flattened, in a cross arrangement and extended horizontally, 2 to 3 cm long and fluted. It has campanulate flowers, 3 to 4 cm, with the outer segments of the perianth purple with a white border, and the interiors red with a medium purple stripe. Its filaments have a yellowish green color, and the anthers are yellow. The style is also yellowish, with 12 lobes of the dark red stigma. Its fruit is globular but irregular in shape, with many scales, pinkish purple, and 4 cm long by 3 cm in diameter. Its walls are fleshy and its pulp has a sweet taste. The seeds are ovoid, 2 mm long, with the foveolate head, very dark brown.

The are found in the Mexican Highlands and are somewhat different from that found in the Mixtec.

In the opinion of Dr. Lindsay, F. macrodiscus is very close to Echinocactus texensis, in regards to its flattened habit, its spines, and the characteristics of the fruit. It could be an intermediate species between the genera Ferocactus and Echinocactus.

During the dry seasons it remains semi-buried, its large napiform roots (in the shape of a turnip) guard its food reserves, protecting them from cold and heat.