 By May 1922, Cárdenas was already professor in the Special Natural Sciences and Chemistry, being an auxiliary senior instructor and later obtained a title at the "Instituto Normal Superior de La Paz".In his career, over a 40 or 50-year period, Cárdenas classified 6,500 species of the flora of Bolivia, and described 180 new species of cactus, with 16 varieties.He also registered 26 types of "Solanum tuberosum" with six varieties.