We provide a short history of the development of phylogenetic concepts for the cactus family in the pre-molecular (here meaning pre-DNA) era, beginning from the creation of the first artificial classification systems, over to natural systems, and on to the progress made in the Post-Darwinian era. Although several authors have presented their ideas on the evolution of Cactaceae, it was the botanists Alwin Berger and Franz Buxbaum who made the most essential contributions towards a cactus phylogeny during the 20^th century. In the second half of that century, new techniques and detailed studies (phytochemistry, anatomy, SEM) helped formulate new concepts or revised established concepts about the evolution of cacti.