Cacti are fascinating plants because they need little water to survive. The cactus, unlike most plants, can grow in the desert. Here are some reasons why:
-- After it rains, the roots of a cactus absorb water. The cactus stores water in its stem.
-- The ribbed surface of the cactus allows it to expand after a rainstorm, when the stem fills up with water. The plant may need this water to last an entire year. As the plant uses the water, the stem becomes smaller.
-- The outside of a cactus is thick and waxy to prevent water loss.
-- A cactus doesn't have any leaves. Leaves require too much moisture, making it too hard for most plants to live in the desert.
