The Collaborative International Dictionary of English v.0.48:

Bird's-foot \Bird's"-foot`\, n. (Bot.)
   A papilionaceous plant, the Ornithopus, having a curved,
   cylindrical pod tipped with a short, clawlike point.
   [1913 Webster]

   Bird's-foot trefoil. (Bot.)
   (a) A genus of plants (Lotus) with clawlike pods. Lotus
       corniculatas, with yellow flowers, is very common in
       Great Britain.
   (b) the related plant, Trigonella ornithopodioides, is also
       European.
       [1913 Webster]