The Collaborative International Dictionary of English v.0.48:

Rowan \Row"an\, n.
   Rowan tree.
   [1913 Webster]

   Rowan barry, a barry of the rowan tree.
      [1913 Webster]

WordNet (r) 3.0 (2006):

rowan
    n 1: Eurasian tree with orange-red berrylike fruits [syn:
         rowan, rowan tree, European mountain ash, Sorbus
         aucuparia]