a)Water Storage: Cacti have plump stems and leaves, called succulents, that act like water sponges, allowing them to survive in dry conditions. b) Spiky Defenders: Those aren't leaves! Cacti have spines instead, which help them avoid thirsty animals and keep precious moisture locked in. c) Shallow Spread: Forget deep roots! Cacti have wide-spreading shallow roots that quickly soak up any precious rain that falls.