Sent to me by an astute reader:
It seemed to me that the response on the Tumbleweed question came from someone who has never been west of the Mississippi. The tumbleweeds we have out west are not native to the Americas, but in fact, come from the Russian Steppes (indeed, some westerner intellectuals refer to the weed as Russian Thistle). They are, indeed, a major annoyance. They grow anywhere a weed will grow, and to enormous size, if allowed. When they dry up, they blow away (actually tumble along) and can collect in huge piles. They are also highly flammable (great fun to burn for us kids back in the pre-ecology days). Did I mention that they are covered with prickly spines?