Reinstatement of Memecylon elegantulum (Melastomataceae) and recircumscription of Memecylon rostratum, two species endemic to Sri Lanka

<i>Memecylonelegantulum</i> Thwaites, a heterotypic synonym of <i>M.rostratum</i> Thwaites, is re-instated based on recent collections and field observations. The two species differ mainly in their habit, inflorescence structure, floral morphology and lamina morphology. A lectotype and an epitype are designated for <i>Memecylonelegantulum</i>, and a lectotype designated for <i>M.rostratum</i>. Both species are confined to the mixed dipterocarp rainforests of Sri Lanka's perhumid south-western 'wet zone'. <i>Memecylonelegantulum</i> appears to be restricted to a relatively small range in Ratnapura district, while <i>M.rostratum</i> has a wider distribution in wet zone.