Cymophyllus

Abstract: Despite the controversy surrounding Cariceae generic and Carex subgeneric limits, most debates centre on a relatively small number of highly reduced unispicate taxa. This study examines Cariceae phylogeny by using all five genera (Schoenoxiphium, Kobresia, Uncinia, Carex, Cymophyllus) and four Carex subgenera (Psyllophora, Vignea, Vigneastra, Carex), with the emphasis of sampling on the tribe's taxonomically difficult unispicate groups (Uncinia, Cymophyllus, Kobresia pro parte, Carex subgenera Psyllophora, and Carex pro parte). Phylogenies based on rDNA internal and external transcribed spacer (ITS, ETS1 f) sequences indicate that the tribe consists of four primary clades (((A, B) C) D) that support a fundamental split between dioecious and androgynous unispicate taxa. Dioecious species are related to multispicate species of either Carex subgenera Carex (Clade D) or Vignea (Clade C), whereas the androgynous species of Uncinia, Kobresia, Cymophyllus, and Carex are related to multispicate species o...

Abstract: Phylogenelic reconstruction for Carex and relatives in tribe Cariceae is complicated by species richness and nearly cosmopolitan distribution. In this investigation, our main objective was to estimate evolutionary relationships in tribe Cariceae using DNA sequence data from two spacer regions in nuclear ribosomal genes (ITS and ETS-lf) combined with noncoding chloroplast DNA (trnL intron, tnrL-trnF intergenic spacer, and trnE-trnD intergenic spacers). Parsimony analyses of separate and combined data and Bayesian analysis of the combined data matrix revealed strong support for monophyly of tribe Cariceae and for monophyly of two major lineages, one comprising principally Carex subgen. Carex and Vigneastra, and the other representing subgen. Vignea. A third clade with representatives from Kabresia and Uncinia, along with Cymophyllus fraserianus, Carex curvula, and several unispicate Carex received weak-to-moderate support. A small clade comprising Schoenoxiphium and two unispicate carices was placed as sister to the clades comprising multispicate Carex species in the parsimony analysis, but sister to the clade of Kobresia, Uncinia, and unispicate Carex in the Bayesian analysis. Two large widespread groups within suhgen. Carex, sect. Hymenochlaenae and sect. Physocarpae S.I. ("bladder sedges"), were highly polyphyletic, while ten clades that grouped species from two or more sections were each strongly supported as monophyletic. Within suhgen. Vignea, three sections were strongly supported as monophyletic while sects. Phaestoglochin and Vulpinae were polyphyletic. Adding the variable ETS-1f region improved resolution and bootstrap support values over previous studies, but many of the characters supporting major branches came from the trnL region.

Abstract: A phylogenetic analysis of Cyperaceae tribe Cariceae was conducted using chloroplast DNA sequences from the gene ndhF and trnL intron and trnL-trnF intergenic spacer. Twenty nine taxa within Cariceae, four outgroup genera, and approximately 3,000 bp of cpDNA were included in the study. Our analysis reveals a monophyletic Cariceae with 100% bootstrap support. Within Cariceae, the South African genus Schoenoxiphium forms a clade that is sister to the rest of the tribe. Our results indicate that genus Carex is paraphyletic with respect to Kobresia, Cymophyllus, and Uncinia. Cymophyllus and Uncinia are nested within an assemblage containing Kobresia, Cymophyllus, and several unispicate Carex species. At the subgeneric level within Carex, only Carex subgenus Vignea appears monophyletic. Several well supported clades were iden- tified within the Cariceae, including the Schoenoxiphium clade, Uncinia clade, Carex subgenus Indocarex/Carex clade, and subgenus Vignea clade; however, relationships among some clades are only moderately supported. Interpretation of the phylogenetic patterns and an account of past phylogenetic hypotheses with respect to the new data are provided.

Abstract: The goal of this study was to review the impact of DNA sequence analyses on our understanding of Cariceae phylogeny, classification and evolution. To explore character evolution, 105 taxa from four different studies were included in an nrDNA ITS + ETS 1f analysis of all recognized genera (Carex, Cymophyllus, Kobresia, Schoenoxiphium, Uncinia) and Carex subgenera (Carex, Psyllophora, Vignea, Vigneastra). As in previous analyses, four major Cariceae clades were recovered: (1) a “Core Carex Clade” (subg. Carex, Vigneastra, Psyllophora p.p); (2) A “Vignea Clade” (subg. Vignea, Psyllophora p.p.); (3) a “Schoenoxiphium Clade” (Schoenoxiphium, subg. Psyllophora p.p.), and (4) a “Core Unispicate Clade” (Uncinia, Kobresia, subg. Psyllophora p.p.). All studies provide strong support (86–100% BS) for the Core Carex and Vignea Clades, but only weak to moderate support (<50%–78% BS) for the Core Unispicate and Schoenoxiphium Clades. The relationships of these groups are unresolved. Studies suggest that Carex is either paraphyletic with respect to all Cariceae genera or to all genera except Schoenoxiphium. Kobresia is a grade, but Uncinia and possibly Schoenoxiphium are monophyletic. The monotypic Cymophyllus is indistinct from Carex subg. Psyllophora species. Character analyses indicate that inflorescence proliferation and reduction have occurred in all major clades, and that the Cariceae’s unisexual flowers have evolved from perfect flowers. The ancestor to Cariceae possessed a multispicate inflorescence with cladoprophylls and female spikelets with tristigmatic gynoecia and closed utricles. This morphology is most similar to extant Carex subg. Carex species, which contradicts the nearly unanimous assumption that the highly compound inflorescences of Schoenoxiphium are primitive. Since taxonomic sampling and statistical support for phylogenies have generally been poor, we advocate the temporary maintenance of the four traditional Carex subgenera with androgynous unispicate species placed within subg. Psyllophora and dioecious and gynaecandrous unispicate species distributed amongst subgenera Carex and Vignea. A collective effort focused on developing new nuclear markers, on increasing taxonomic and geographic sampling, and on studying development within the context of phylogeny, is needed to develop a phylogenetic classification of Cariceae.