grasslike or rushlike plant growing in wet places having solid stems, narrow grasslike leaves and spikelets of inconspicuous flowers
source: WordNet 3.0
Any plant of the genus Carex, perennial, endogenous, innutritious herbs, often growing in dense tufts in marshy places. They have triangular jointless stems, a spiked inflorescence, and long grasslike leaves which are usually rough on the margins and midrib. There are several hundred species.