Erythrina x sykesii is a hybrid, commonly called Australian Coral Tree; but it is actually not a native of any country.   A Balboa Park gardener told me it came from somewhere else to Australia, but botanists can’t agree on where it was first developed… probably as a Erythrina lysistemon cross. After it had been planted all over Australia, it was adopted by gardeners from coastal warm climates all around the world. Propagation is by cuttings only because it doesn’t make seeds.