IN THE PLANT WORLD THE ROAD RUNNER'S OPPOSITE NUMber is certainly the cactus. To most people--and quite properly--it is the desert plant par excellence. Many kinds are, like the road runner, at home in the desert and nowhere else. Like the road runner also they belong to a family of pioneers which moved into arid America and changed itself radically to meet the new conditions. Most of the cuckoo tribe live by following other habits in other environments. The relatives of the desert cacti do the same.
Members of the Sonoran branch of the family come in all shapes and sizes from tiny two-inch pincushions full of pins