Have you seen those old movies about the wild West? Near the end, the good guy and the bad guy stand facing each other at opposite ends of the only street in town. The local folks, knowing what will happen, clear the street. They slam doors and shutter windows. The general store hangs up a “closed” sign. Only two men remain outside. The wind blows a cloud of dust from the street. A dog barks in the distance. With another gust of wind a tumbleweed… tumbles… between them. Where do tumbleweeds come from? Do they germinate on the tumble, grow on the tumble, and die on the tumble? No. In the spring, they grow as thick, green bushes. When the spring rains stop, their roots cannot find enough water to sustain them. They wither and fall over. Eventually, their shallow roots are no longer able to keep them anchored to the ground. They literally dry up and blow away. Mesquite trees, which can grow in the same area, are just the opposite. Even after a prolonged drought, if you cut one down, it grows back. If you cut down what grows back, it will grow back again. You could dig down five or ten feet below ground, cut it down, and burn the stump. You would soon have a mesquite grove as dozens (if not hundreds!) of severed roots sprout. A significant difference between tumbleweed and mesquite trees is in the roots.