Why do cacti store water?
Show answer & explanation
Answer: To survive long dry spells in the desert
To survive long dry spells in the desert ✓ — A cactus can draw on water stored in its fleshy stem when rain does not arrive. After rain, it takes up water and stores a reserve for the next dry spell. A waxy surface reduces water loss, helping that reserve last longer.
To stay cool when the desert heat peaks — Keeping cool is not the main function of a cactus's water reserve. Stored water can buffer temperature changes, but the plant still needs a supply of water when the soil is dry. Saving water rather than constantly spending it on evaporative cooling is especially useful in a desert.
To support the weight of heavy flowers — Supporting heavy flowers is not what a cactus's large water reserve is for. Water pressure does help plant tissues stay firm, but the reserve also sustains the cactus when it has no flowers. Its value is carrying the plant through a long gap between rains.