The spines of a cactus create shade, preventing its stem from getting sunburned. The largest cacti can reach heights of more than 66 feet (20 meters). Learn more in Cacti, one of the titles in the Plant Kingdom series. This series uses vivid images and interesting facts to explore different types of plants found around the world.

Includes index.

What is a plant? -- Cacti -- How cacti grow -- Cactus life cycle -- Cactus habitats -- Survival in dry ecosystems -- Cacti worldwide -- Cacti and people -- Activities -- Quiz.