The old lady cactus (Mammillaria hahniana ssp woodsii) belongs to Cactaceae (the Cactus family). It is an evergreen succulent perennial that is native to Guanajuato, in central Mexico. The stems are flattened globose to club-shaped, with sunken apex, it can reach 5 cm in height and 8 cm in diameter. The tubercles are conical, and the axiles are filled by woolly white hairs. It has 2-4 central spines and 25-30 radial spines. The flowers are pink with darker pink midstripe, 12-15 mm in diameter, and bloom in spring and summer.