Revisiting of Carex sect. Confertiflorae s.l. (Cyperaceae): new data from molecular and morphological evidence and first insights on Carex biogeography in East Asia|植物分类学数据集|系统发育学数据集

Carex sect. Confertiflorae s.l., contains ca. 40 species and diverse in E
Asia. It has one of the most unstable delimitations in the literature, and
the section was proposed to split into two sections up to five different
ones. Recent phylogenetic reconstructions showed Confertiflorae s.l. not
to be monophyletic. In this study we investigate the phylogenetic
structure, morphological affinities, and biogeographic history of sect.
Confertiflorae s.l. We performed a taxon-based approach to explore the
morphological affinities of the species considered in sect.
Confertiflorae. We studied macromorphological observations and
micromorphology of the nutlets using SEM, and used five molecular markers
to reconstruct the phylogeny. The placement of all the species on a
previously published megaphylogeny was tested in a preliminary exploration
using a scaffolding approach. Then a core of species was selected to run
the main analyses. The phylogenetic analyses confirmed the polyphyly of
sect. Confertiflorae s.l., whose representatives were found within five
distinct clades, with sect. Confertiflorae s.s. and sect. Molliculae
clades were found to be closely related and contained the majority of the
species. The composition of the two clades agreed with the morphological
structure of the group, and we confirmed an exclusive combination of
features. The origin of the two clades was found to be in the early
Pliocene while the majority of the diversification events within each
clade took place during the Pleistocene. Eventually, we proposed the
rearrangement of sect. Confertiflorae as previously conceived as three
independent sections: sects. Alliiformes, Molliculae, and Paludosae.