Nineteen different species of Acacia in the Americas contain cyanogenic glycosides, which, if exposed to an enzyme which specifically splits glycosides, can release hydrogen cyanide (HCN) in the "leaves" [REF].
Some Acacia species containing cyanogens include Acacia erioloba, A. cunninghamii, A. obtusifolia, A. sieberiana, and A. sieberiana var.