Fairy Ring Mushrooms
This large ring popped up between our house and the neighbors', mid-September 2003.
Apparently the formation of fairy rings is due to the using up of fungus food in the center - the mushrooms live on decaying organic matter in the soil. When they use it up, they die, but in the meantime they've dropped spores which result in new mushrooms growing at the periphery of the area where the nutrients have already been used up.
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