It will sometimes grow to a height of fifteen feet, and in swampy places is so dense that it is difficult to keep even a few horses in sight when driving through it; after it dries and the seeds fall to the ground, the stalks break off, and the sweep of the water over the plains during the succeeding year gathers these dry stems against the trees in enormous masses like small haystacks, and there they remain until a bushfire reduces them to ashes.
Source: tatoeba (11757080)