Source : Webster's Revised Unabridged Dictionary (1913)

Barrenwort \Bar"ren*wort`\, n. (Bot.)
   An herbaceous plant of the Barberry family ({Epimedium
   alpinum}), having leaves that are bitter and said to be
   sudorific.

Source : WordNet®

barrenwort
     n : slow-growing creeping plant with semi-evergreen leaves on
         erect wiry stems; used as ground cover [syn: {bishop's
         hat}, {Epimedium grandiflorum}]