poison bush

from the GNU version of the Collaborative International Dictionary of English.

• 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.
• The plant Myoporum deserti, often distinguished as Ellangowan poison bush or dogwood poison bush.
• The ulmaceous plant Trema cannabina, which, though not poisonous, is injurious to stock because of its large amount of fiber.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun 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
• noun either of two Australian plants of the genus Swainsona that are poisonous to sheep