the coevolution of cacti?

Answer 1

what do you mean?

maybe you mean that plants not related to cacti can look like cacti because they live in arid climates - for example succulent euphorbias in Africa. google up Euphorbia resinifera, euphorbia heptagona, and many other species of succulent Euphorbia. but this phenomeneon is NOT called coevolution.

Coevolution is evolution of two or more organisms whose lives more or less depend on each other. like a parasite and host, so you must ask "the coevolution of cacti and .......?" like maybe a specific pollinator that depends on a specific cactus.