Cardenas

Spanish (Cárdenas): habitational name from places in the provinces of Almería and Logroño named Cárdenas, from the feminine plural of cárdeno ‘blue’, ‘bluish purple’ (Late Latin cardinus, from carduus ‘thistle’). Presumably the noun tierras ‘lands’ is to be understood, and the reference is to land covered with bluish plants, such as thistles or vines.