The Collaborative International Dictionary of English v.0.48:

weeping tree broom \weeping tree broom\ n.
   a small shrubby tree of New Zealand having weeping branches
   and racemes of white to violet flowers followed by woolly
   indehiscent 2-seeded pods.

   Note: a broom is any of various shrubs of the genera Cytisus
         or Genista or Spartium having long slender branches and
         racemes of yellow flowers.
         [WordNet 1.5]

WordNet (r) 3.0 (2006):

weeping tree broom
    n 1: small shrubby tree of New Zealand having weeping branches
         and racemes of white to violet flowers followed by woolly
         indehiscent two-seeded pods