Mexican living-rock cactus

The living-rock cactus, belonging to the genus Ariocarpus, comprises eight species native to Texas and Mexico, thriving in limestone-rich soil. These low-growing cacti are characterized by a rosette of flattened or protruding tubercles and typically lack spines, though they may be covered in woolly hairs. They store water in their thickened taproot and mucilage canals to survive dry winters.1

The flowers, measuring 2 to 5 cm in diameter, can be magenta, white, yellow, or cream, with fruits ripening just before the summer rains. Some species, such as Ariocarpus agavoides, A. bravoanus, and A. scaphirostris, are endangered due to habitat loss and overcollection. The plants contain alkaloids, making them mildly hallucinogenic. The Ariocarpus fissuratus species is also known as mescal.12