Hidden Species of Anacardiaceae in the Andean Cloud Forests: A Revision of Schinus Section Myrtifolia

Abstract Schinus comprises 42 species distributed across a broad range of vegetation types in southern South America. The previous phylogenetic study recovered eight well-supported lineages in Schinus. The simple-leaved species were grouped in a strongly supported clade that was resolved into five internal clades, one of which is Schinus sect. Myrtifolia. This is a group with some species reaching the highest elevations attained by Anacardiaceae. The 11 species of this section are mostly endemic to Andean cloud forests from Argentina, Bolivia, and Peru. Here, we present a taxonomic revision of Schinus section Myrtifolia and provide an identification key, descriptions of taxa including four new species: Schinus congestiflora, Schinus obliqua, Schinus tarijensis, and Schinus villosa, recognize a variety at species level and a new name at a new rank, as well as present synonyms and designate three lectotypes. We also include illustrations, distribution maps, comments on the taxonomy and nomenclature, preliminary conservation assessments, and pollen characterization for three species.