Opuntia megarrhiza Rose is a species of plant in the family Cactaceae. It is endemic to the state of San LuÃÂs PotosÃÂ in northeastern Mexico.
It is known only from five populations, around the summits of La Trinidad and ÃÂlvarez Mountain Ranges, in San Luis PotosÃÂ, northeastern Mexico. Its natural habitat is subtropical or tropical dry lowland grassland.
It is an endangered species, threatened by habitat loss, grazing, and harvest for traditional medicinal uses.