Family: Cactaceae (Cactus family).
Occurrence: Occasional, from garden refuse. Wheel Pear (Opuntia robusta) is abundant in parts of Maldon, Tarrengower and Baringhup. It is easily recognised by the circular branches.
The other local prickly pears have oval branches. They apparently originate as garden refuse. They show little sign of spreading, but to be sure, it makes sense to eradicate them wherever found. A small amount of effort now might prevent days, weeks or years of effort later on.
Because they come from garden specimens, a range of species is involved.