The fruits of M. malabathricum ‘Alba’ have a green coloured rind while those found on plants that produce pink/mauve colored flowers are reddish brown. https://photoplusbyritasim.wordpress.com/2012/05/15/melastoma-malabathricum-straits-rhododendron-4/
A ripe fruit revealing the soft sweet pulp and numerous orange seeds.
Note: Variety vs, Cultivar.
Varieties often occur in nature and most varieties are true to type. That means the seedlings grown from a variety will also have the same unique characteristic of the parent plant.
For example, there is a white flowering Straits Rhododendron that was found in nature. Its scientific name is Melastoma malabathricum var. alba. The varietal term “alba” means white. If you were to germinate seed from this variety, most if not all would also be white flowering.
Cultivars are not necessarily true to type. In fact cultivar means “cultivated variety” therefore, a cultivar was selected and cultivated by humans.
Photos: Singapore 20120514