Strombocactus

A species of the Moctezuma River canyon with persistent, strong spines and yellow flowers. Its seeds develop without an aril, and its root system spreads shallowly sideways. Some literature calls it Chichimecactus corregidorae, but POWO retains the name Strombocactus corregidorae.

A cactus with overlapping tubercles, short-lived spines and very small seeds with a pale aril. The nominate subspecies flowers white or cream, while subspecies esperanzae develops magenta flowers. Seed and nectary anatomy describe their reproduction in much greater detail than stem appearance alone.