approximately 2,000 species of cactus grow/growsin the dry regions of the new world. ordinary non-desert plants absorb water from the soil through their roots and give off water from their leaves. cactus roots spread out widely but stay near the surface in order to absorb more water during the infrequent desert rainstorms. beacause most cactuses have no leaves, they avoed a huge loss of water. while ordinary plants perform photosynthesis in green leaves, obtain/obtainingthe carbohydrates they use for energy, cactuses perform this process on the green surfaces of their stems. cactuses have thick stems which/inwhich a great deal of water can be stored. the most impressive cactus is the saguaro, which has stems and branches half a meter thick and towers 15 meters high.

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