A<unk>  is the above-ground part of a plant that, once mature and dry, disengages from the root and<unk> s away in the wind.  Usually, the<unk>  is the entire plant apart from the roots, but in a few species it is a flower cluster. The<unk>  habit is most common in steppe and desert climates.  The<unk>  is a diaspore, aiding in dispersal of propagules (seeds or spores).  It does this by scattering the propagules either as it<unk> s, or after it has come to rest in a wet location.  In the latter case, the<unk>  opens  mechanically as it absorbs water; apart  from its propagules,  the<unk>  is dead.
Tumble weed
Pinworm
Thimbleweed
Ringworm
Hookworm
Samarium 
Flea
Psilocybin mushrooms