The new combination Monocarpia maingayi (Hook.f. & Thomson) I.M.Turner (Annonaceae), based on Cyathocalyx maingayi Hook.f. & Thomson, is proposed and a lectotype is designated. Monocarpia maingayi is native to the Malay Peninsula and Sumatra. It has previously been referred to as Monocarpia marginalis (Scheff.) J.Sinclair. Differences between Monocarpia maingayi and M. kalimantanensis P.J.A.Kessler of Borneo are highlighted. Four species of Monocarpia are recognised, and a key to them is presented.
