These plants sprout, flower and go to seed in a very short period time. The seeds are dropped and remain dormant in the soil till the next season of rain. The drought-evading plants have a lot in common with the deciduous plants that lose their leaves in the fall and remain dormant during the freezing temperatures. The drought-evading plants maintain life by dropping their leaves and going into a state of dormancy until the temperature drops and the moisture returns in adequate supply to renew plant activity. Drought-resisting plants, the most common being the cactus, are very hardy and tenacious in their grasp on a hostile environment.
Moisture is stored in the spongy stem or root systems of the cactus during rainfall.
The cactus is like the camel and his hump. The camel can draw on the reserves in the hump while the cactus relies on the moisture in the fleshy stem during periods of drought. The green in the stems has taken the place of leaves in the photosynthesis process. Leaves are very small or non existent. The needles or spines can act as protection against marauders.