How would Dialium Indum end up in Reunion? Especially when closer relatives are around, perhaps like
https://en.wikipedia.org/wiki/Dialium_madagascariense Also keep in mind this is a rainforest tree, so it would likely need the stress of breaching a canopy to fruit, - 20-30 years? With little sustenance, difficulty in planting as a crop or even decoration.. how or why would Indum a SE asian native end up in Africa.
Don't know how they are different, but the Dialium wikipedia page lists several species, just that Indum is 'general' or most well known scientific name. It would make sense that there are several almost indistinguishable species, because of their distance apart from each other.
on a side note... This is one of the best hardwoods in the world, especially for house building because of the long straight bole of this rainforest canopy tree.