Cactus (family Cactaceae) is a plant primarily native to the Americas, known for its thick, water-storing stems and spines instead of leaves. Adapted to dry, arid conditions, cacti can survive in deserts by storing water and using specialized photosynthesis. They produce colorful flowers and fruits, some of which are edible, like the prickly pear. Cacti are popular in gardens and as houseplants.