The cacti in the collection (just over 500 species) vary in shape and size: tall columnar, round biznagas, bushy and cluster-like plants, as well as small species with showy flowers. Among the larger plants, the old ones stand out (Cephalocereus senilis), with its stems covered with white fur, which can measure up to 15 meters in the wild. Other columns of the Garden are the organs (Pachycereus marginatus) and pitayas (Cephalocereus marginatus), with their bodies lined with fine spines.
Among the largest biznagas, the acitrón stands out (Ferocactus histrix), native to Charco del Ingenio, along with other species that came to the Garden as a result of various rescues, such as the Zimapán biznaga or “barrel of gold”, with its showy yellow crown (Echinocactus grusonii). One of these species, perhaps the fastest growing (Echinocactus platyacanthus), reaches a great thickness and up to 2.5 meters in height.
There are also cacti with a bushy appearance, a variety of nopales and their relatives (genus opuntia), both natives and guests of the Botanical Garden. Some are densely prickly, and others offer edible stems and fruit. The collection also includes climbing cacti (Selenicereus sp., Peniocereus serpentinus and several species of the genus Acanthocereus), most of them with large, white and nocturnal flowers, as well as creeping ones, (Stenocereus eruca), which roots as it grows horizontally.
Among the smaller growing cacti, the genus Mammillaria stands out for its diversity of shapes and flowers, whose more than 180 species are well represented in the collection.