A saguaro cactus (Carnegiea gigantca) has a smooth, waxy skin that seals in moisture. Cacti expand by absorbing water when it is available and shrink as they lose water slowly during times of drought. The saguaro cactus flowers every year and can have up to 200 blooms. It can withstand high temperatures, but cannot survive temperatures below freezing. Back to To Plant or Not to Plant? Metric Converter | Vocabulary | Teacher Resource | Back to Top |