Assessment of the degree of establishment of five introduced Melastomataceae taxa in South Africa.
The Melastomataceae contains well-known horticultural species as well as some species that are invasive particularly on Pacific and Indian Ocean islands. Three Pleroma species, a Heterocentron species and a Melastoma hybrid were recently found outside of cultivation in Durban, KwaZulu-Natal, South Africa. To get a more accurate understanding of their current populations and distributions, we surveyed the wider Durban area and southwards to Port St. Johns in the Eastern Cape and included herbarium voucher information and distribution data from the Southern African Plant Invader Atlas. The results of weed risk assessments and field observations suggest that the populations of H. subtriplinervium, P. granulosum and P. urvilleanum are relatively static and seem to be casual garden escapes. On the other hand, populations of P. mutabile and the Melastoma hybrid are expanding locally, and these species may become more widely invasive in South Africa.