Taxonomic adjustments in Mimoseae (Fabaceae): new genera described to accommodate Zygia/Inga inundata and Zygia sabatieri, and a recombination of Marmaroxylon ocumarense

Abstract In recent phylogenetic studies of legumes the species Zygia/Ingainundata and Zygiasabatieri have been shown to not belong in neither Inga nor Zygia. Inga inundata was originally placed in the genus Inga based on morphological characters such as having pinnate leaves, but was transferred to the genus Zygia when the pod was discovered. The species was placed in its own section in Zygia, Zygia sect. Ingopsis, due to the similarity in leaf morphology to the species in Inga. Zygia sabatieri is another species placed in its own section in Zygia, Zygia sect. Pseudocojoba, due to similarity in flower morphology to the legume genus Cojoba. The genus Marmaroxylon has been synonymized under Zygia but the species Marmaroxylonocumarense has been shown to be closer related to species of the genus Macrosamanea and is not resolved within Zygia. In this study these results are compared and discussed. Zygia/Ingainundata and Zygiasabatieri are morphologically distinct from Inga and Zygia, and from each other, and taxonomic adjustments are made. Two new genera are described, Ingopsis gen. nov. to accommodate Zygia/Inga inundata and Pseudocojoba gen. nov. to accommodate Zygia sabatieri. In addition, Marmaroxylon ocumarense is transferred to the genus Macrosamanea where it fits phylogenetically and morphologically.