DOI: 10.5061/dryad.37pvmcvj3
title: Data from: Systematics of the giant sedges of Carex sect. Rhynchocystis (Cyperaceae) in Macaronesia with description of two new species

description: Populations of Carex sect. Rhynchocystis (Cyperaceae) from the
 Macaronesian archipelagos (Azores and Madeira) have traditionally been
 treated either as a variety of the widely distributed Western Palearctic
 C. pendula, or directly synonymized under it. However, recent phylogenetic
 studies have shown that Azorean populations of C. pendula display a
 certain degree of differentiation from mainland plants, while the
 phylogenetic relationships of Madeiran populations remain unclear. Here we
 perform an integrated systematic study focused on the Macaronesian
 populations of Carex sect. Rhynchocystis to elucidate their phylogenetic
 relationships and taxonomic status. We reconstructed a molecular phylogeny
 based on five DNA regions and conducted a multivariate morphological
 analysis. Divergence time estimates show that the Macaronesian populations
 can be traced back to a Plio-Pleistocene origin. Our results suggest that
 these island populations of C. pendula are better treated as two distinct
 species within Carex sect. Rhynchocystis (i.e., C. leviosa from the Azores
 and C. sequeirae from Madeira). We provide morphological characters to
 differentiate the new species from C. pendula s.str., detailed
 descriptions of the three taxa, a revised key for the entire section, as
 well as detailed analytical drawings of the two newly described species.
 We also perform a critical evaluation of the taxonomic diversity of Carex
 in the Azores and Madeira. Finally, we assessed the conservation status of
 the new species at a global scale under IUCN categories and criteria,
 resulting in the proposal of the categories “Least Concern” for C. leviosa
 and “Critically Endangered” for C. sequeirae
description: <b><i>Phylogenetic
 Analyses</i></b>—Samples of all species of <i>Carex.
 </i>sect. <i>Rhynchocystis</i> were used to
 representatively cover its range. We sampled the following populations (1
 specimen per population): (1) six of <i>C. agastachys</i>; (2)
 five of <i>C. bequaertii</i> subsp.<i>
 bequaertii</i> and three of <i>C. bequaertii</i>
 subsp.<i> mossii</i>; (3)<i> </i>three of<i>
 C. microcarpa</i>; (4)<i> </i>eight of <i>C.
 pendula</i>; (5)<i> </i>one of<i> C.
 penduliformis</i>; (6) five of <i>C. pendula </i>from
 the Azores, treated by us as <i>C.</i>
 <i>leviosa</i>; (7) five of <i>C. pendula </i>from
 Madeira, treated by us as<i> C. sequeirae</i>; and (8) two
 species from each of the closely related <i>Carex</i><i>
 </i>sect. <i>Ceratocystis </i>Dumort.,
 <i>Carex</i><i> </i>sect. <i>Phacocystis
 </i>Dumort.,
 <i>Carex</i><i> </i>sect. <i>Sylvaticae
 </i>Rouy, and
 <i>Carex</i><i> </i>sect. <i>Spirostachyae
 </i>(Drejer) L.H.Bailey, as outgroups (Míguez et al. 2017; Appendix
 1). We sequenced and analyzed three cDNA (i.e., <i>atpIH,
 matK</i>, and<i>
 rpl32-trnL<sup>UAG</sup></i>) and two nDNA (i.e., ETS
 and ITS) regions. <b><i>Macromorphological
 Study</i></b>—The morphological study included a total of 75
 herbarium specimens from 13 herbaria (E, BM, K, LISU, M, MADJ, MADM, MHA,
 P, SEV, TUM, UPOS, UPS; Appendix 2; abbreviations follow Thiers 2020). Our
 sampling was designed to explore the morphological variation within the
 monophyletic group formed by <i>C. agastachys</i>, <i>C.
 leviosa</i>, <i>C. pendula</i> and <i>C.
 sequeirae.</i>