SPECIES DELIMITATION IN GENIPA (RUBIACEAE) USING INTEGRATIVE TAXONOMY

Abstract

The genus Genipa L. is a widespread, lowland, Neotropical lineage of trees in the coffeefamily, Rubiaceae. There is long-standing disagreement on the number of species thatshould be recognised in the genus. Here, I use an integrative taxonomy approachencompassing genomic, morphological and distribution data to resolve the classification ofGenipa. A comprehensive species phylogeny was produced under the multi-speciescoalescent model, using a high-resolution dataset from target sequence capture data.Results from a 245 loci dataset strongly supports Genipa spruceana Steyerm., oftensynonymised with Genipa americana L., as a distinct monophyletic species. Similarly, themonophyly of Genipa infundibuliformis Zappi & Semiris also strongly supported. The speciesdelimitation of Genipaspruceana is corroborated bymorphological data and Genipainfundibuliformis is corroborated by morphological and distribution data. The phylogeny alsoshows that the widespread species G. americana hasthree distinct well-supported cladeswithin it. These are interpreted as three independently evolving lineages. However, followingan integrative taxonomy approach no new classification is recommended at this point, untilreliable determination can be made with evidence other than genomic data. Additionally, theimportance of leaf indumentum as a diagnostic character in Genipa was investigated andscanning electron micrograph images of leaf trichomes are presented.