The Collaborative International Dictionary of English v.0.48:

Box \Box\ (b[o^]ks), n. [As. box, L. buxus, fr. Gr. ?. See Box
   a case.] (Bot.)
   A tree or shrub, flourishing in different parts of the world.
   The common box (Buxus sempervirens) has two varieties, one
   of which, the dwarf box (Buxus suffruticosa), is much used
   for borders in gardens. The wood of the tree varieties, being
   very hard and smooth, is extensively used in the arts, as by
   turners, engravers, mathematical instrument makers, etc.
   [1913 Webster]

   Box elder, the ash-leaved maple (Negundo aceroides), of
      North America.

   Box holly, the butcher's broom (Russus aculeatus).

   Box thorn, a shrub (Lycium barbarum).

   Box tree, the tree variety of the common box.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Buxine \Bux"ine\, n. (Chem.)
   An alkaloid obtained from the Buxus sempervirens, or common
   box tree. It is identical with bebeerine; -- called also
   buxina.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Buxus sempervirens
    n 1: large slow-growing evergreen shrub or small tree with
         multiple stems; extensively used for hedges or borders and
         topiary figures [syn: common box, European box, Buxus
         sempervirens]