The Collaborative International Dictionary of English v.0.48:

weeping beech \weeping beech\ n.
   a variety of European beech (Fagus pendula, Fagus
   sylvatica pendula) with pendulous limbs.
   [WordNet 1.5]

WordNet (r) 3.0 (2006):

Fagus pendula
    n 1: variety of European beech with pendulous limbs [syn:
         weeping beech, Fagus pendula, Fagus sylvatica
         pendula]