The Collaborative International Dictionary of English v.0.48:

Finochio \Fi*no"chi*o\ (?; 277), n. [It. finocchio fennel, LL.
   fenuclum. See Fennel.] (Bot.)
   An umbelliferous plant (F[oe]niculum dulce) having a
   somewhat tuberous stem; sweet fennel. The blanched stems are
   used in France and Italy as a culinary vegetable.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Foeniculum dulce
    n 1: grown especially for its edible aromatic bulbous stem base
         [syn: Florence fennel, Foeniculum dulce, Foeniculum
         vulgare dulce]