The park is named for the large saguaro cactus, native to its desert environment. It is the largest and one of the slowest growing of all cacti, reaching up to 15 meters high and living for several centuries. Plants can weigh up to 8 tons, partly because of the large amount of water the stems can hold – after rainfall the cactus can absorb hundreds of gallons in a short time. The saguaro may be only 6 inches high after 10 years, and the characteristic branched appearance is reached only after around 80 years.