Geographical vs. ecological diversification inCarexsectionPhacocystis(Cyperaceae): Patterns hidden behind a twisted taxonomy

• DOI: 10.1111/jse.12731
• Publication Date: 2021-02-06T12:18:04Z
• Authors: Carmen Benítez‐Be...; Santiago Martín‐B...; Charlotte S. Bjorå; Sebastian Gebauer; Andrew L. Hipp; Matthias H. Hoffmann; Modesto Luceño; Tyril M. Pedersen; Anton Reznicek; Eric Roalson; Polina Volkova; Okihito Yano; Daniel Spalink; Pedro Jiménez‐Mejías
• Keywords: 0301 basic medicine; 03 medical and health sciences; 15. Life on land

AbstractCarexsectionPhacocystis(Cyperaceae) is one of the most diverse and taxonomically complex groups of sedges (between 116 and 147 species), with a worldwide distribution in a wide array of biomes. It has a very complicated taxonomic history, with numerous disagreements among different treatments. We studied the biogeography and niche evolution in a phylogenetic framework to unveil the relative contribution of geographical and ecological drivers to diversification of the group. We used a large species sampling of the section (82% of extant species) to build a phylogeny based on four DNA regions, constrained with a phylogenomic HybSeq tree and dated with six fossil calibrations. Our phylogenetic results recovered sectionPhacocystiss.s. (core Phacocystis) as sister to sectionPraelongae. Ancestral area reconstruction points toward the N Pacific as the cradle for the crown diversification of sectionPhacocystisduring the Middle Miocene. Wide distributions were recurrently inferred across deep nodes. Large Northern Hemisphere lineages with geographical congruence were retrieved, pointing toward the importance of allopatric divergence at deep phylogenetic levels, whereas within‐area speciation emerges as the predominant pattern at shallow phylogenetic level. The Southern Hemisphere (Neotropics, SW Pacific) was colonized several times from the Northern Hemisphere. The global expansion ofCarexsectionPhacocystisdid not entail major ecological changes along the inner branches of the phylogeny. Nevertheless, ecological differentiation seems to gain importance toward recent times.