whitethorn

from WordNet (r) 3.0 (2006)

whitethorn
    n 1: thorny Eurasian shrub of small tree having dense clusters
         of white to scarlet flowers followed by deep red berries;
         established as an escape in eastern North America [syn:
         {whitethorn}, {English hawthorn}, {may}, {Crataegus
         laevigata}, {Crataegus oxycantha}]

from The Collaborative International Dictionary of English v.0.48

Whitethorn \White"thorn`\, n. (Bot.)
   The hawthorn.
   [1913 Webster]