carex

from WordNet (r) 3.0 (2006)

Carex
    n 1: large genus of plants found in damp woodlands and bogs and
         ditches or at water margins: sedges [syn: {Carex}, {genus
         Carex}]

from The Collaborative International Dictionary of English v.0.48

Carex \Ca"rex\, n. [L., sedge.] (Bot.)
   A numerous and widely distributed genus of perennial
   herbaceous plants of the order {Cypreace[ae]}; the sedges.
   [1913 Webster]