Delonix regia
The prickly pear illustrates the dilemma of plant introductions: while many authors see exotic plants as a threat to the native flora, others argue that they have not yet been linked directly to the extinction of a native species, and that some may actually provide economic or ecological benefits. A number of plants native to Madagascar have become invasive in other regions, such as the traveller's tree in Réunion and the flamboyant tree ("Delonix regia") in various tropical countries.