Why Doesn't the Cactus Have Leaves?

The cactus does have leaves, but not ordinary ones. They are the sharp and hard thorns pointing out from its surface. As you know, plants consume water everyday for their growth, but at the same time some moisture evaporates from their leaf stomas. However, the cactus grows in deserts, where it is hot and dry and there is littie rain. In such circumstances, the cactus gets very littie moisture. If the cactus had the leaves like trees grOW17 in other areas, it would certainly wither and die due continuous loss of moisture from its leaf stomas. A years of evolution the leaves have developed their presented shape, which prevents nearly all the moisture from eva- porating. In this way the

cactus is able to grow in deserts from one generation to another.