The Collaborative International Dictionary of English v.0.48:

Hare's-foot fern \Hare's"-foot` fern`\ (-f[oo^]t` f[~e]rn`).
   (Bot.)
   A species of fern (Davallia Canariensis) with a soft, gray,
   hairy rootstock; -- whence the name.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Davallia canariensis
    n 1: fern of the Canary Islands and Madeira [syn: Canary Island
         hare's foot fern, Davallia canariensis]