The Collaborative International Dictionary of English v.0.48:

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.
          [Webster 1913 Suppl.]