The San Pedro cactus (Echinopsis pachanoi), traditionally known from South America, originally from Ecuador and Peru where the cactus grows in mountains at an altitude of 2 to 3 km. The cactus can be recognized by its ribs, grows quickly and has strong roots. If the cactus falls over it will litter the surrounding soil with its offshoots. The cactus will grow faster in a moist environment but can survive for years if it lives in a dry environment.
Place the cutting on the surface of some potting compost mixed with sand and perlite. Keep the cutting in the shade or indirect sunlight and water it regularly. After about six months the cactus will have formed roots and can be repotted with the same type of soil.