Cacti in Australia: Introduced, Not Native

Cacti are native exclusively to the Americas (except Rhipsalis baccifera, which naturally occurs in Africa/Sri Lanka—likely bird-dispersed). Australia has no native cacti.

Introduced Species

• Prickly pear (Opuntia stricta): Introduced 1788 (cochineal dye industry); became catastrophic invasive (24M ha by 1920s); controlled by Cactoblastis cactorum moth (1926)—classic biocontrol success.
• Hudson pear (Cylindropuntia rosea), rope pear (C. imbricata): Invasive in rangelands.
• Ornamental escapes: Echinopsis, Cereus, Mammillaria in gardens, occasionally naturalized.

Australia's Native Succulents

Convergent evolution produced cactus-like forms: Stapeliads (carrion flowers), Euphorbias, Portulaca, Carpobrotus (pigface), Halosarcia (samphire). Adapted to aridity without cactus lineage.

Biosecurity

Australia bans most cactus imports. Declared weeds (Opuntia, Cylindropuntia) require control. Report sightings to state agriculture departments.

The desert looks cactus-ready—but Australia evolved its own spiny toolkit.