Revisiting of <i>Carex</i> sect. <i>Confertiflorae</i> s.l. (Cyperaceae): New data from molecular and morphological evidence and first insights on <i>Carex</i> biogeography in East Asia

Carex sect. Confertiflorae s.l. is a medium-sized species group (ca. 40 species) with its center of diversity in E Asia (China and Japan). According to morphological traits, the section has been proposed split into two sections (sects. sensu Ohwi Molliculae Ohwi) up five different ones s.s., Molliculae, Dispalatae Ohwi, Ischnostachyae Alliiformes Akiyama). Recent phylogenetic reconstructions showed not be monophyletic, as traditionally considered part it were found belong other clades, whereas ascribed nested within it. In this study, we investigated structure, affinities, biogeographic history We employed taxon-based approach explore affinities compared micromorphology nutlets almost all taxa using SEM. included samples representing 31 species/subspecies used nuclear (ETS ITS) three plastid (trnL-F, matK, rpl32-trnL UAG) molecular markers reconstruct phylogeny group. The analyses confirmed polyphyly s.l., whose representatives distinct clades. From these, closely related contained majority species. composition clades agreed structure group, an exclusive combination features (namely color basal sheaths, presence bract sheath, peduncle lowest spike, inflorescence sex distribution, shape pistillate glume apex, veins utricle, among others) characterizing each origin was early Pliocene; however, diversification events clade took place during Pleistocene. This illustrates that although regarded having little potential ecological space for diversify due climate stability, groups sedges sub-endemic from area may have fairly recent glaciations. rearrangement previously conceived independent sections: monotypic Alliiformes, Paludosae.