Source : Webster's Revised Unabridged Dictionary (1913)

Poison bush \Poison bush\ In Australia:
   (a) Any fabaceous shrub of the genus {Gastrolobium}, the
       herbage of which is poisonous to stock; also, any species
       of several related genera, as {Oxylobium},
       {Gompholobium}, etc.
   (b) The plant {Myoporum deserti}, often distinguished as
       {Ellangowan poison bush} or {dogwood poison bush}.
   (c) The ulmaceous plant {Trema cannabina}, which, though not
       poisonous, is injurious to stock because of its large
       amount of fiber.

Source : WordNet®

poison bush
     n 1: any of various Australian evergreen shrubs of the genus
          Gastrolobium having whorled compound leaves poisonous to
          livestock and showy yellow to deep reddish-orange
          flowers followed by two-seeded pods [syn: {poison pea},
          {gastrolobium}]
     2: either of two Australian plants of the genus Swainsona that
        are poisonous to sheep [syn: {darling pea}]