Source : Webster's Revised Unabridged Dictionary (1913)

Bishop's cap \Bish"op's cap`\ (Bot.)
   A plant of the genus {Mitella}; miterwort. --Longfellow.

Source : WordNet®

bishop's cap
     n : any of various rhizomatous perennial herbs of the genus
         Mitella having a capsule resembling a bishop's miter
         [syn: {miterwort}, {mitrewort}]