Biography and contributions of Joaquim do Espírito Santo (1901-1984) to the botany of Guinea-Bissau and São Tomé and Príncipe

A biography of Joaquim Viegas da Graça do Espírito Santo (1901–1984) is provided by integrating information from botanical collections and from his record as a civil servant. Born in São Tomé Island (São Tomé and Príncipe), he finished his studies in Portugal in 1924, spent most of his career as an agricultural technical engineer in Guinea-Bissau (1927–1956), and after retiring continued collecting, mostly in São Tomé. He collected at least 5 412 herbarium specimens, including 23 types of plant names. He remains the most prolific plant collector in Guinea-Bissau and is a somewhat neglected collector in São Tomé and Príncipe. He also produced 22 publications. Finally, these contributions are contextualised, taking into consideration that he was one of the few non-white plant collectors from the Portuguese colonial period, while being a member of a family that was pivotal in the inception of independence movements in Lusophone Africa.