Source : Webster's Revised Unabridged Dictionary (1913)

Rowan tree \Row"an tree`\ [Cf. Sw. r["o]nn, Dan. r["o]nne, Icel.
   reynir, and L. ornus.] (Bot.)
   A european tree ({Pyrus aucuparia}) related to the apple, but
   with pinnate leaves and flat corymbs of small white flowers
   followed by little bright red berries. Called also {roan
   tree}, and {mountain ash}. The name is also applied to two
   American trees of similar habit ({Pyrus Americana}, and {P.
   sambucifolia}).