This study identified all invasive plants in Australia, using GBIF-mediated occurrences to map their distributions prior to introduction ‘down under’. Using the purpose and pathway of introduction to identify patterns in naturalization, their results show that 12% of total Australian flora is naturalized—but just two families account for more than a third. Originating mainly from Europe (47.4%), 65% of the plants were introduced as ornamentals, but now more than a third of the naturalized plants are classified as weeds.
The overall results indicate a long-term shift in the plants’ origins and uses, starting from food originating in Europe, through food and ornamentals from North America, to ornamental and accidental species from South Africa. Despite these changes, species introduction has remained more or less constant at the rate of around 20 species per year since 1880.