Cereus repandus f. monstruosus (Monstrose Apple Cactus), also known as Cereus peruvianus f. monstruosus, is a large shrubby or tree-like…
Meaning: Strange, preternatural, or monstrous.
Derivation: A Latin adjective also spelled "monstrosus."
Whereas the generic name must be unique, there are often two or more genera with the same specific epithet. The same epithet can also be used within a species for subspecies, varieties, and forms.
Here is a full list of succulents with this epithet. Click on the photo or the name of the plant for which you wish to see further information.