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: Webster's Revised Unabridged Dictionary (1913)