Cacti are native only to the Americas, and native species are found in at least 46 states. They may look like tough, rugged plants, but in many cases they are "living on the edge" in extreme environments. Their survival depends on well-balanced ecosystems. Cacti often provide food and shelter for other organisms in areas where those resources are scarce. Because cactus species have limited ranges and they are often slow-growing, any extended threat can exterminate entire populations.
Take a journey with me through four typical—and not so typical—cactus habitats!