MakingCarexmonophyletic (Cyperaceae, tribe Cariceae): a new broader circumscription

Abstract

Carex (Cyperaceae), with an estimated 2000 species, nearly cosmopolitan distribution and broad range of habitats, is one of the largest angiosperm genera and the largest in the temperate zone. In this article, we provide argument and evidence for a broader circumscription of Carex to add all species currently classified in Cymophyllus (monotypic), Kobresia (c. 60 species), Schoenoxiphium (c. 15 species) and Uncinia (c. 70 species) to those currently classified as Carex. Carex and these genera comprise tribe Cariceae (subfamily Cyperoideae, Cyperaceae) and form a well‐supported monophyletic group in all molecular phylogenetic studies to date. Carex as defined here in the broad sense currently comprises at least four clades. Three are strongly supported (Siderostictae, core Vignea and core Carex), whereas the caricoid clade, which includes all the segregate genera, receives only weak to moderate support. The caricoid clade is most commonly split into two clades, one including a monophyletic Schoenoxiphium and two small clades of species of Carex s.s., and the other comprising Kobresia, Uncinia and mostly unispicate species of Carex s.s. Morphological variation is high in all but the Vignea clade, making it extremely difficult to define consistent synapomorphies for most clades. However, Carex s.l. as newly circumscribed here is clearly differentiated from the sister groups in tribe Scirpeae by the transition from bisexual flowers with a bristle perianth in the sister group to unisexual flowers without a perianth in Carex. The naked female flowers of Carex s.l. are at least partially enclosed in a flask‐shaped prophyll, termed a perigynium. Carex s.s. is not only by far the largest genus in the group, but also the earliest published name. As a result, only 72 new combinations and 58 replacement names are required to treat all of tribe Cariceae as a single genus Carex. We present the required transfers here, with synonymy, and we argue that this broader monophyletic circumscription of Carex reflects the close evolutionary relationships in the group and serves the goal of nomenclatural stability better than other possible treatments. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179, 1–42.

Vicariance versus dispersal across Beringian land bridges to explain circumpolar distribution: A case study in plants with high dispersal potential

“…Carex section Glareosae, comprised of 26 species and two subspecies (Maguilla & Escudero, 2016;Maguilla et al, 2015) with a mainly circumboreal distribution (Figure 1; Egorova, 1999;Toivonen, 2002), is a good model for this study for many reasons: (1) different distribution patterns, from widely distributed species to narrow endemics (Egorova, 1999;Maguilla et al, 2015;Toivonen, 2002) as well as species with unusual distribution patterns such as bipolar or amphitropical (C. canescens L. and C. lachenalii Schkuhr, respectively; Moore & Chater, 1971;Vollan et al, 2006); (2) high sensitivity to climate change due to the arctic distribution of species (Figure 1; Maguilla et al, 2015); (3) enough molecular information to get a well-supported phylogeny reflecting a strong phylogenetic hypothesis for our study group (Global Carex Group, 2015, 2016Maguilla et al, 2015) and (4) accurate and reliable knowledge of species distribution through modern flora treatments (Egorova, 1999;Toivonen, 2002). Despite the absence of specific syndromes for long-distance dispersal in Carex propagules (Escudero, Valcarcel, Vargas, & Luceño, 2008), long-distance dispersal ability in this genus has been F I G U R E 1 Occurrence of species within Carex section Glareosae G. Don (Cyperaceae) following Govaerts et al (2007) using "Botanical countries" as per Brummitt (2001).…”

Productive Overcompensation of Alpine Meadows in Response to Yak Grazing in the Eastern Qinghai-Tibet Plateau

“…The Qinghai-Tibet Plateau (QTP) is the world’s largest and highest plateau, which covers an area of approximately 2.5 million km 2 in China and hosts the world’s largest pastoral alpine ecosystem (Miehe et al, 2019). Two distinct types of alpine pasture exist in the QTP: alpine steppe in the northern and northwestern plateau, with the dominant species being Stipa (Poaceae) species; and alpine meadow in the eastern and southeastern QTP, dominated by Kobresia (Cyperaceae) species (particularly K. pygmaea ; Zhang et al, 2007; Global Carex Group, 2015). Alpine meadow or sedge pasture, sometimes forming a velvety turf, extends from the Qilian Mountains to the Himalayas, covering an area of 450,000 km 2 (Miehe et al, 2014).…”

Cyperaceae in Mexico: Diversity and distribution

“…If compared with Madagascar, where the Cariceae are 11 % of the Cyperaceae (Muasya et al 2011) . This is a result of recent phylogenetic findings and taxonomic rearrangements (Larridon et al 2011, 2014, Bauters et al 2014, the Global Carex Group 2015. According to these references, Uncinia is included into Carex, whereas Kyllinga, Lipocarpha, Oxycarium and Remirea are now part of Cyperus (Table 2), besides Pycreus and Torulinum, previously subsumed.…”

“…Refining of the database involved nomenclatural updating, detection of synonyms, review of doubtful names and exclusion from the Mexican flora of names of taxa whose presence in the country has not been corroborated. The classification at the subfamily and tribe levels follows Muasya et al (2009a, b) and the circumscription of genera follows Dorr (2014), Larridon et al (2011Larridon et al ( , 2013Larridon et al ( , 2014, Bauters et al (2014), and The Global Carex Group (2015Group ( , 2016. To verify the names of species and authors, the web sites Tropicos (www.tropicos.org) and The International Plant Names Index (www.ipni.org) were used.…”