The Collaborative International Dictionary of English v.0.48:

Osier \O"sier\, n. [F. osier: cf. Prov. F. oisis, Armor. ozil,
   aozil, Gr. ?, ?, ?, L. vitex, and E. withy.] (Bot.)
      (a) A kind of willow (Salix viminalis) growing in wet
          places in Europe and Asia, and introduced into North
          America. It is considered the best of the willows for
          basket work. The name is sometimes given to any kind
          of willow.
      (b) One of the long, pliable twigs of this plant, or of
          other similar plants.
          [1913 Webster]

                The rank of osiers by the murmuring stream.
                                                  --Shak.
          [1913 Webster]

   Osier bed, or Osier holt, a place where willows are grown
      for basket making. [Eng.]

   Red osier.
      (a) A kind of willow with reddish twigs (Salix rubra).
      (b) An American shrub (Cornus stolonifera) which has
          slender red branches; -- also called osier cornel.
          [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Cornel \Cor"nel\ (-n?l), n. [OF. cornille, cornoille, F.
   cornouille, cornel berry, LL. cornolium cornel tree, fr. L.
   cornus, fr. cornu horn, in allusion to the hardness of the
   wood. See Horn.]
   1. (Bot.) The cornelian cherry (Cornus Mas), a European
      shrub with clusters of small, greenish flowers, followed
      by very acid but edible drupes resembling cherries.
      [1913 Webster]

   2. Any species of the genus Cornus, as Cornus florida,
      the flowering cornel; Cornus stolonifera, the osier
      cornel; Cornus Canadensis, the dwarf cornel, or
      bunchberry.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Cornus stolonifera
    n 1: common North American shrub with reddish purple twigs and
         white flowers [syn: red osier, red osier dogwood, red
         dogwood, American dogwood, redbrush, Cornus
         stolonifera]