Pot: 10 cm.
M. grusonii in its monstrous form presents shape anomalies or asymmetries that will never be the same or identical in plants, making each of them unique and for this reason much appreciated by collectors around the world. In its normal form it is a globe-shaped cactus of green color and slightly depressed at the apex. M. grusonii f. monstrous has large dimensions, usually reaches 30 cm in diameter. It has protruding rhomboidal tubercles, above which there are the white and fluffy areoles. From the latter come out the radial and central spines: the first are thin, white and short while the central ones are generally less numerous (2-3), longer, more robust and brown in color. The flowering period is spring and at the apex of the plant bloom beautiful bell-shaped flowers of fuchsia or light pink color with a central stripe of darker color.