Wednesday, April 14, 2010
As I was driving to work this morning my mind was strangely bombarded with the thoughts of tumbleweeds. Not sure why but here are some pictures to enjoy and a spot of history on these plants.
A tumbleweed is the above-ground part of a plant that, once mature and dry, disengages from the root and tumbles 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 plants. 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.