A matter of warts: a taxonomic treatment for Drypetes verrucosa (Putranjivaceae, Malpighiales) and a new cauliforous species from Cameroon and Nigeria, D. stevartii Alejandro Quintanar 1 , Bonaventure Sonké 2,3 , Murielle Simo-Droissart 2 , Patricia Barberá 3 , Moses Libalah 2,4 , David J. Harris 5 1 Herbarium MA, Unidad de Herbarios, Real Jardín Botánico de Madrid CSIC, Madrid, Spain 2 Plant Systematics and Ecology Laboratory, Higher Teachers’ Training College, University of Yaoundé I, Yaoundé, Cameroon 3 Africa and Madagascar Department, Missouri Botanical Garden, Saint Louis, Missouri, United States of America 4 Department of Plant Biology, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon 5 Royal Botanic Garden Edinburgh, Edinburgh, United Kingdom Corresponding author: Alejandro Quintanar (quintanar@rjb.csic.es) Academic editor: Brecht Verstraete  ♦  Received 15 February 2023  ♦  Accepted 14 March 2023  ♦  Published 26 April 2023 Abstract Background and aims – Specimens of a new tree species in the genus Drypetes (Putranjivaceae) distributed in Cameroon and eastern Nigeria, D. stevartii, were associated with D. verrucosa, another tree species endemic to Gabon, due to its warty fruits and to the overall morphological resemblances of both species. Material and methods – Te present study is based on the study of 20 gatherings of D. verrucosa and 26 gatherings of D. stevartii. Morphological observations on herbarium specimens belonging to the new species and D. verrucosa were carried out in order to describe them. Key results – Tis treatment includes the detailed descriptions of these two species, the typifcation of their names, a comparative table summarizing their main morphological diferences, an identifcation key, photographs of both, as well as information about their distribution, habitat, and phenology. Preliminary IUCN Red List assessments show that both D. verrucosa and D. stevartii are ‘Near Treatened’ species. Keywords Central Africa, conservation, dioecy, fruit dispersal, herbarium, isothiocyanates, IUCN Red List assessments, pollination, taxonomy INTRODUCTION Te pantropical genus Drypetes Vahl (Putranjivaceae Endl., Malpighiales) consists of 218 species of shrubs and trees, of which 83 occur in continental Africa and the Malagasy Region (Quintanar et al. in press), that inhabit high to medium rainfall areas, from evergreen forests to relatively dry savannahs. Tese plants have simple, petiolate, and penninerved leaves with oblique to unequal-sided bases, which are usually alternate and lack glands. Tey are mostly dioecious (exceptionally polygamo-dioecious or monoecious) and present apetalous, more or less small and inconspicuous fowers that are solitary or, much more frequently, grouped in long-lived clusters or exceptionally in cymes. Flowers have a shallow cup of sepals and exposed nectar-bearing disc that in the male fowers is surrounded or penetrated by the stamens. In the female fowers, the disc surrounds the ovary. In many species, the fowers give of a more or less pungent chemical smell, sometimes reminiscent of horseradish, that can be easily perceived at a considerable distance from the plant. Tis smell pertains to the end-metabolites of the glucosinolate biochemical Plant Ecology and Evolution 156 (2): 160–173, 2023 https://doi.org/10.5091/plecevo.102004 Copyright Alejandro Quintanar, Bonaventure Sonké, Murielle Simo-Droissart, Patricia Barberá, Moses Libalah, David J. Harris. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Plant Ecology and Evolution is published by Meise Botanic Garden and Royal Botanical Society of Belgium. RESEARCH ARTICLE