Have you ever seen firefighters using a fire hose? The hose looks stiff and fat while water is running through it. But when the fire is put out and the firefighters turn off the water, the empty hose is limp.
Many plants are something like a fire hose. As long as their roots keep pumping water, their stems and leaves stand up straight and stiff. But a plant loses water through its leaves. If the plant doesn’t get enough water to replace the lost water, it will soon flop over, just like an empty fire hose. Perhaps you’ve seen this happen to potted plants. They begin to droop when they need water.
Plants that live in deserts, where there is very little water; have special ways of collecting and storing water. For example, the roots of some cactus plants grow down deep or spread out very far to find water. Cactus plants store the water in their thick, fleshy stems. When there is no rain, they live off the stored water.
Picture Credit : Google