poison bush vs suffrutex

poison bush and suffrutex both are nouns.

Word	Noun	Adjective	Verb	Adverb
poison bush	Yes	No	No	No
suffrutex	Yes	No	No	No

As nouns, suffrutex is a hypernym of poison bush; that is, suffrutex is a word with a broader meaning than poison bush:

poison bush: either of two Australian plants of the genus Swainsona that are poisonous to sheep
suffrutex: low-growing woody shrub or perennial with woody base

Other hypernyms of poison bush include subshrub.

poison bush (noun)	suffrutex (noun)
either of two Australian plants of the genus Swainsona that are poisonous to sheep	low-growing woody shrub or perennial with woody base
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