Tumbleweed

A tumbleweed is the above-ground part of any of a number of plants that, once mature and dry, disengage from the root and tumble away in the wind. Usually, the tumbleweed is the entire plant apart from the roots, but in a few species it is a flower cluster. The tumbleweed habit is most common in steppe and desert climates. The tumbleweed is a diaspore, aiding in dispersal of propagules (seeds or spores). It does this by scattering the propagules either as it tumbles, or after it has come to rest in a wet location. In the latter case, the tumbleweed opens mechanically as it absorbs water; apart from its propagules, the tumbleweed is dead.