Overview of Psychotria in Madagascar (Rubiaceae, Psychotrieae), and of Bremekamp's foundational study of this group

Abstract Taylor, C.M. (2020). Overview of Psychotria in Madagascar (Rubiaceae, Psychotrieae), and of Bremekamp's foundational study of this group. Candollea 75: 51–70. In English, English abstract. Psychotria L. (Rubiaceae, Psychotrieae) is a large pantropical genus that is one of the largest genera in Madagascar, with almost all of its species endemic to the island and an unusually wide range of morphological variation. Cornelis E.B. Bremekamp (1888–1984) presented a detailed taxonomic treatment for Madagascar and the Comores that classified 143 species in Psychotria and six segregate genera, and that has been influential in Rubiaceae systematics but also problematic. Molecular systematic studies have found Bremekamp's six genera nested within Psychotria, but did not study most of their unusual characters. Here his genera and their morphological features are studied in light of our current knowledge of Psychotria in Madagascar and overall understanding of this genus. Some unusual characters are detailed here for Malagasy Psychotria. A new name, Psychotria deflexiflora C.M. Taylor, is published as a legitimate name for Psychotria penduliflora Bremek. Received: May 21, 2019; Accepted: February 7, 2020; First published online: March 24, 2020