The cactus family is one of the truly American plant families. There are now cactus plants in other parts of the world, but they all came in the beginning from the Americas.
Many people think of deserts when they hear the word "cactus." Not all cacti live in deserts, but most of them do. Desert cacti are sometimes called the heroes of the plant world because they can stand heat and dryness that would kill most plants. The cacti pictured live in the deserts of southwestern United States. All these cacti have good roots for taking in water after a rain. They also have several ways of keeping the water they take in from evaporating. Their green stems must do the work that leaves do for most green plants. Having no leaves cuts down the chance for the water taken in to evaporate. A coating of wax on the stems helps hold in water, too. Their stems are big enough to be good storage tanks. And they are fluted so they can expand and contract easily. Raising cacti is a popular hobby. People like them for their strange shapes. Besides, cactus flowers are beautiful. They come in many colors—yellow, orange, scarlet, pink, and purple. No cactus has flowers more beautiful or fragrant than the night-blooming cereus. Its flowers are pure white. A flower is open for only one night. When this cactus is in bloom people gather from miles around to see it.
