Integrative taxonomy delimits species within the Duranta sprucei complex

Abstract

Species boundaries in the Duranta sprucei complex have been a taxonomic challenge, displaying complex patterns of variation in vegetative morphology. This complex includes plants distributed in the Neotropical Andes from Bolivia to Colombia and the mountains of Central America. Previous authors delimited taxa morphologically, and different criteria have been reflected in the recognition of a variable number of taxa. Lineage divergence forms a temporal process whence populations may diverge morphologically and/or ecologically, and this contingent property of taxa should provide the criteria necessary for species delimitation. To clarify the taxonomy of the Duranta sprucei complex, an integrative methodology based on a modified Population Aggregation Analysis and a Species Distribution Modelling approach was employed. Morphology was used to discriminate species with different predicted distributions that share environmental parameters. As a result, the complex is here circumscribed to include four previously recognized species, D. benthamii, D. costaricensis, D. penlandii and D. sprucei, one former variety elevated to the rank of species, D. espinosae, and a new species, D. dickinsonii, endemic to the Peruvian Yungas. One new synonym and a new combination are also herein presented.