Phylogeny of Lantana, Lippia, and related genera (Lantaneae: Verbenaceae)

Abstract

Premise Lantana and Lippia (Verbenaceae) are two large Linnean genera whose classification has been based on associated fruit traits: fleshy vs. dry fruits and one vs. two seed‐bearing units. We reconstruct evolutionary relationships and the evolution of the two fruit traits to test the validity of these traits for classification. Methods Previous studies of plastid DNA sequences provided limited resolution for this group. Consequently, seven nuclear loci, including ITS, ETS, and five PPR loci, were sequenced for 88 accessions of the Lantana/Lippia clade and three outgroups. Results Neither Lantana nor Lippia is monophyletic. Burroughsia, Nashia, Phyla, and several Aloysia species are included within the clade comprising Lantana and Lippia. We provide a hypothesis for fruit evolution and biogeographic history in the group and their relevance for classification. Conclusions Fleshy fruits evolved multiple times in the Lantana/Lippia clade and thus are not suitable taxonomic characters. Several sections of Lantana and Lippia and the small genera are monophyletic, but Lippia section Zappania is broadly paraphyletic, making circumscription of genera difficult. Lippia sect. Rhodolippia is a polyphyletic group characterized by convergence in showy bracts. Species of Lantana sect. Sarcolippia, previously transferred to Lippia, are not monophyletic. The clade originated and diversified in South America, with at least four expansions into both Central America and the Caribbean and two to Africa. The types species of Lantana and Lippia occur in small sister clades, rendering any taxonomy that retains either genus similar to its current circumscription impossible.

Nested singletons in molecular trees: Utility of adding morphological and geographical data from digitized herbarium specimens to test taxon concepts at species level in the case of Casearia (Salicaceae)

“…Our approach shows that quantitative evaluation of nonsequenced specimens that were identified based on morphological characters and using existing prephylogenetic treatments can be successful in evaluating the status of so‐called nested singletons that were found in phylogenetic analyses. Such singletons are frequent in published molecular phylogenetic trees based on multiple sequence alignments of few to multiple loci (Bengtson et al, 2021 ; Lu‐Irving et al, 2021 ; García‐Moro et al, 2022 ) and as well in phylogenomic analyses using RAD (Böhnert et al, 2022 ) or hyb seq data (Jones et al, 2019 ; Xu & Chen, 2021 ). Under normal circumstances, one would target several specimens of a species complex to address species delimitation, then also ideally combining molecular, morphological, ecological, and distributional data in an integrative taxonomy approach.…”

“…Species may vary considerably in their infraspecific phylogenetic structure when multiple individuals from different populations throughout their geographic range are included (Borsch et al, 2018 ). Despite their frequent occurrence (see for example trees published by Bengtson et al, 2021 ; Frost et al, 2021 ; Lu‐Irving et al, 2021 ; Majure et al, 2021 , García‐Moro et al, 2022 ), cases of nested singletons are almost never discussed.…”

“…Despite their frequent occurrence (see for example trees published by Bengtson et al, 2021;Frost et al, 2021;Lu-Irving et al, 2021;Majure et al, 2021, García-Moro et al, 2022, cases of nested singletons are almost never discussed.…”

Making Lantaneae (Verbenaceae) taxonomy useful: A phylogenetic classification

“…300 species, Lantaneae sensu Marx & al. (2010) are the largest radiation in Verbenaceae (Lu‐Irving & Olmstead, 2013; Cardoso & al., 2021; Lu‐Irving & al., 2021) and represent a notable element in tropical and temperate regions of the Americas. They include herbs, shrubs, subshrubs, and rarely trees widely distributed from North America and the Caribbean to Patagonia in South America (Atkins, 2004; Cardoso & al., 2021).…”

“…in an expanded Aloysia . A third study focused primarily on “core Lantaneae” (Lu‐Irving & al., 2021) found that neither Lantana nor Lippia are monophyletic. Several small genera ( Burroughsia , Diphyllocalyx , Isidroa , Nashia , Phyla , Salimenaea , Troncosoa ), as well as five North American species of Aloysia , belong to a clade otherwise composed of species currently, or in recent treatments, considered to belong to Lantana and Lippia .…”