仙人掌大多生长在炎热、干燥的沙漠地带。它的茎宽大、肥厚,能贮存大量的水分。仙人掌全身长满了刺,你知道这是为什么吗?原来植物体内的水分,大部分是由叶子蒸发掉的。仙人掌身上的刺其实就是它的叶子,它们呈针状,这样就大大减少了蒸发水分的面积,使仙人掌在干旱、少雨的环境中 Cacti mostly grow in the hot, dry desert. Its stem is large, fat, and can store a lot of water. Cactus covered with thorn, do you know why? The original plant water, most of the leaves are evaporated. The prickles on the cactus are actually its leaves, which are needle-shaped, thus greatly reducing the area of ​​evaporated water, allowing cacti in arid and dry conditions