Advances in understanding the phylogenetic relationships of the subfamily Larreoideae using morphological and molecular evidence

Larreoideae are one of the major representatives of Zygophyllaceae in South America. In this work, we analysed the phylogenetic relationships of species in the subfamily Larreoideae using morphological and molecular data in a total evidence context. We also evaluated the monophyly of Larreoideae considering both morphological and a combined set of data (morphological + molecular), providing a discussion of the phylogenetic position of its members. Finally, we constructed a molecular tree based on nuclear and plastid sequences, analysing them separately. The integration of morphological and molecular data reaffirms the monophyly of Larreoideae. The phylogenetic analysis supports the traditional genera as well-supported groups. Species in Bulnesia are clearly separated by molecular and morphological characters which reinforce the consolidation of the genus Gonopterodendron. Therefore, we recognize eight genera forming Larreoideae. We confirm the taxonomic position of Guaiacum angustifolium (Porlieria angustifolia) in Guaiacum supported by molecular and morphological data, and suggest the inclusion of Pintoa chilensis and Metharme lanata in Larreoideae based on morphological features shared with members of the subfamily.