A cactus is a unique type of plant that thrives in dry, desert environments. Known for their thick, fleshy stems, cacti store water to survive long periods without rain. They often have sharp spines instead of leaves, which help reduce water loss and protect them from animals that might want to eat them. Cacti come in many shapes and sizes, from small, round ones to tall, tree-like varieties. Some popular types include the saguaro cactus, which can grow to be quite large, and the barrel cactus, known for its round shape. These fascinating plants are not only resilient but also beautiful, often blooming with vibrant flowers.