There are many varieties of cacti, from the tiny potted houseplant to the 40-foot tall giant desert saguaro. The most spectacular areas where the cactus flourish are in the desert areas of northern Mexico, Arizona, New Mexico and southern Texas. In the springtime, usually through the month of May, beautiful displays of cactus flowers cover the desert landscapes with flashes of bright red, yellow, white and orange. The sugary centers of the flowers also serve as a food source for bees, birds and small desert animals.