<p>Nutgrass - Cyperus rotundus.
Considered a pest plant.
</p>
Photographed by myself with Fuji FinePix 2650, on Dec. 9, 2005.
No machine-readable author provided. <a href="//commons.wikimedia.org/wiki/User:Rickjpelleg" title="User:Rickjpelleg">Rickjpelleg</a> assumed (based on copyright claims).
CC BY 2.5
No machine-readable source provided. Own work assumed (based on copyright claims).