In 1949 a single plant of Musa mannii Baker, grown in Trinidad from seeds imported from Java, was incorrectly identified as Musa sanguinea Hook. f. As a consequence, the circumscription of M. mannii became confused. M. mannii is very rare or extinct in its indigenous area in Assam, India. However, it is grown in many botanic gardens worldwide. In contrast, M. sanguinea is a common sympatric species with M. aurantiaca in upper Assam and Arunachal Pradesh, India, but it is today unknown to most botanists. The aim of this study is to settle the true identity of M. mannii and M. sanguinea. The names are typified, as well as Musa × kewensis Baker (M. mannii × ornata).