Source : Webster's Revised Unabridged Dictionary (1913)

Hare's-foot fern \Hare's"-foot` fern`\ (Bot.)
   A species of fern ({Davallia Canariensis}) with a soft, gray,
   hairy rootstock; -- whence the name.

Source : WordNet®

hare's-foot fern
     n : either of two ferns of the genus Davallia having a soft gray
         hairy rootstock