Carex Sect Research Articles

Utilizing RADseq data for phylogenetic analysis of challenging taxonomic groups: A case study in Carex sect. Racemosae.

Relationships among closely related and recently diverged taxa can be especially difficult to resolve. Here we use both Sanger sequencing and next-generation RADseq data sets to estimate phylogenetic relationships among species of Carex section Racemosae (Cyperaceae), a clade largely restricted to high latitudes and elevations. Interest in relationships among these taxa derives from questions about the species' biogeographic histories and possible links between diversification and Pleistocene glaciations. A combination of approaches and molecular markers were used to estimate relationships among Carex species within sect. Racemosae and taxa from closely related sections. Nuclear and chloroplast loci generated by Sanger sequencing were analyzed with *BEAST, and SNP data from RADseq loci were analyzed as a concatenated data set using maximum likelihood and as independent loci using SVDquartets. Sanger sequencing data sets resolved relationships among taxa at intermediate phylogenetic depths (albeit with low levels of support). Only the RADseq data resolved relationships with strong support at all phylogenetic depths. Moreover, different methods and data partitions of the RADseq data resulted in nearly identical topologies. Carex sect. Racemosae is a strongly supported clade, although a handful of species were found to group with closely related sections. Herbarium specimens up to 35 yr old successfully produced informative RADseq data. Despite the short read lengths of RADseq data, they nevertheless resolved relationships that Sanger sequencing data did not. Resolution of the phylogenetic relationships among recently and rapidly diversifying taxa within sect. Racemosae clades suggest a role for the Pleistocene glaciations in clade diversification.

Anthracoidea caricis-reznicekii (Anthracoideaceae), a new species on Carex reznicekii, and A. eburneae, a new record for the USA

A new ovariicolous smut fungus, Anthracoidea caricis-reznicekii on Carex reznicekii (C. sect. Acrocystis), is described and illustrated from the USA. The new species is compared with the known Anthracoidea species on sedges in Carex sect. Acrocystis and other closely related sections. Anthracoidea caricis-reznicekii is characterized by a complex of characters: medium-sized spores (15–24.5 μm long), thick spore wall (up to 6.0 μm thick), with conspicuous, often numerous (up to 8) protuberances, and warts 0.2–0.5 μm high. A key to the four known Anthracoidea species on sedges in section Acrocystis is provided. Anthracoidea eburneae, previously known only from Canada, is reported for the first time from the USA, on Carex eburnea.

Phylogeny and morphology of Anthracoidea pamiroalaica sp. nov. infecting the endemic sedge Carex koshewnikowii in the Pamir Alai Mts (Tajikistan)

A novel Anthracoidea species, A. pamiroalaica on the endemic sedge Carex koshewnikowii, is described and illustrated from the Pamir Alai Mts in Tajikistan (Central Asia). The new species is phenotypically nearly identical with Anthracoidea sempervirentis, but clearly divergent genetically. Phylogenetic analyses based on LSU sequences showed affinity of Anthracoidea pamiroalaica to A. baldensis, A. rupestris, A. capillaris, and A. vankyi infecting host sedges in different Carex sections (Baldenses, Rupestres, Chlorostachyae, and Phaestoglochin, respectively), but not to A. misandrae, and A. sempervirentis, two sequenced species parasitic on host species from the section Aulocystis. This phylogenetic placement is briefly discussed in the context of Anthracoidea evolution.

Carex huangshanica (sect. Rhomboidales, Cyperaceae), a new species from Anhui, eastern China

Carex huangshanica X. F. Jin & W. J. Chen, a new species from Anhui Province of eastern China, is described and illustrated. It belongs to Carex sect. Rhomboidales and resembles C. longirostrata in having perigynia gradually contracted into a long beak at apex; orifice 2-lobed with long teeth; achenes abruptly contracted into a beak at apex. It differs from C. longirostrata in having upper spikes aggregated, pistillate scales shortly awned at apex, perigynia nearly glabrous, and achenes ovoid. Micromorphological characters of the perigynia and achenes under scanning electron microscope are compared between the new species and C. longirostrata. Carex huangshanica has glabrous perigynia (vs. pubescent perigynia in C. longirostrata), achenes abruptly contracted in a short curved beak at apex, and only one silica body is present in each epidermal cell (vs. achenes of C. longirostrat that are contracted in a short coiled beak at apex, and without silica body in epidermal cells).

Carex jianfengensis (Carex sect. Rhomboidales, Cyperaceae), a New Species from Hainan, China.

A new species of Carex sect. Rhomboidales, C. jianfengensis, is described and illustrated from Hainan, China. The new species is similar to C. zunyiensis but differs in having involucral bracts sparsely hispid and with ca.1 cm long sheaths; inflorescence with 4 spikes, terminal spike ca. 2.5 cm long, lateral spikes 2–3.5 × 0.7–1 cm; staminate glumes narrowly ovate, ca. 5 mm; pistillate glumes triangular-lanceolate, 5–7 mm; perigynia 6–8 × 3 mm and pubescent on veins; nutlet 4–5 mm long, rhombic-ovoid, trigonous, base with shortly stipitate, apex abruptly contracted into a erect short beak, and not expanding into an annulate orifice.

Phylogeny, systematics, and trait evolution of Carex section Glareosae.

• The circumboreal Carex section Glareosae comprises 20-25 currently accepted species. High variability in geographic distribution, ecology, cytogenetics, and morphology has led to historical problems both in species delimitation and in circumscribing the limits of the section, which is one of the major tasks facing caricologists today.• We performed phylogenetic reconstructions based on ETS, ITS, G3PDH, and matK DNA sequences from 204 samples. Concatenation of gene regions in a supermatrix approach to phylogenetic reconstruction was compared to coalescent-based species-tree estimation. Ancestral state reconstructions were performed for eight morphological characters to evaluate correspondence between phylogeny and traits used in traditional classification within the section.• The results confirm the existence of a core Glareosae comprising 23-25 species. Most species constitute exclusive lineages, and relationships among species are highly resolved with both the supermatrix and coalescent-based species-tree approaches. We used ancestral state reconstruction to investigate sources of homoplasy underlying traditional taxonomy and species circumscription. We found that even species apparently not constituting exclusive lineages are morphologically homogeneous, raising the question of whether paraphyly of species is a phylogenetic artifact in our study or evidence of widespread homoplasy in characters used to define species.• This study demonstrates the monophyly of Carex section Glareosae and establishes a phylogenetic framework for the section. Homoplasy makes many of morphological characters difficult to apply for taxon delimitation. The strong concordance between supermatrix and species-tree approaches to phylogenetic reconstructions suggests that even in the face of incongruence among molecular markers, section-level or species-level phylogenies in Carex are tractable.

Direct long‐distance dispersal best explains the bipolar distribution of Carex arctogena (Carex sect. Capituligerae, Cyperaceae)

AbstractAimThe bipolar disjunction, a biogeographical pattern defined by taxa with a distribution at very high latitudes in both hemispheres (> 55° N; > 52° S), is only known to occur in about 30 vascular plant species. Our aim was to use the bipolar species Carex arctogena to test the four classic hypotheses proposed to explain this exceptional disjunction: convergent evolution, vicariance, mountain‐hopping and direct long‐distance dispersal.LocationArctic/boreal and temperate latitudes of both hemispheres.MethodsA combination of molecular and bioclimatic data was used to test phylogeographical hypotheses in C. arctogena. Three chloroplast markers (atpF–atpH, matK and rps16) and the nuclear ITS region were sequenced for all species in Carex sections Capituligerae and Longespicatae; Carex rupestris, C. obtusata and Uncinia triquetra were used as outrgroups. Phylogenetic relationships, divergence‐time estimates and biogeographical patterns were inferred using maximum likelihood, statistical parsimony and Bayesian inference.ResultsCarex sections Capituligerae and Longespicatae formed a monophyletic group that diverged during the late Miocene. Two main lineages of C. arctogena were inferred. Southern Hemisphere populations of C. arctogena shared the same haplotype as a widespread circumboreal lineage. Bioclimatic data show that Southern and Northern Hemisphere populations currently differ in their ecological regimes.Main conclusionsTwo of the four hypotheses accounting for bipolar disjunctions may be rejected. Our results suggest that direct long‐distance dispersal, probably southwards and mediated by birds, best explains the bipolar distribution of C. arctogena.

Three new, early diverging Carex (Cariceae, Cyperaceae) lineages from East and Southeast Asia with important evolutionary and biogeographic implications

Traditional Cariceae and Carex (1966 spp.) classifications recognised five genera (Carex, Cymophyllus, Kobresia, Schoenoxiphium, Uncinia) and four subgenera (Carex, Vignea, Vigneastra, Psyllophora). However, molecular studies have shown that only Carex, divided into five major lineages (the Core Carex, Schoenoxiphium, Core Unispicate, Vignea and Siderostictae Clades), is natural. These studies have also suggested that many early diverging tribal lineages are East Asian in origin, but the sampling of East Asian groups has been poor, and support for relationships within and among major Cariceae clades has been weak. To test deep patterns of relationship in Carex we assembled the longest sequence dataset yet (ITS, ETS 1f, matK, ndhF, rps16; ca. 4400bp) with taxonomic sampling focused on critical East and Southeast Asian Carex sections that have blurred subgeneric limits (Decorae, Graciles, Mundae) or have been at the heart of theories on tribal origins (Hemiscaposae, Indicae, Surculosae, Euprepes, Mapaniifoliae, Hypolytroides). Results indicate that subg. Vigneastra is highly polyphyletic (in five of seven major lineages recognised), and they provide the strongest support yet seen for all previously recognised major Cariceae clades in a single analysis (⩾93% BS). Moreover, results provide strong evidence for three previously unrecognised early diverging East and Southeast Asian lineages: a “Hypolytroides Clade” (sect. Hypolytroides) sister to the Siderostictae Clade, and for a “Dissitiflora Lineage” (sect. Mundae) and a morphologically diverse “Small Core Carex Clade” (sects. Graciles, Decorae, Mapaniifoliae, Euprepes, Indicae) as successive sisters to approximately 1400 species in the Core Carex Clade. Our findings also suggest that morphological diversification may have occurred in clades dominated by Asian species followed by canalization to a narrower range of morphologies in species-rich, cosmopolitan lineages.

Carex procumbens (Carex sect. Rhomboidales, Cyperaceae), a new species from Hainan, China

Carex procumbens, a new species of Carex sect. Rhomboidales from Hainan, China, is described and illustrated. The new species is similar to C. longipetiolata but differs in culms soft and usually prostrate on the ground, having narrower leaves with the leaf base gradually narrowed, with 2–3 spikes, terminal spike 8–12 mm long, lateral spikes 5–15 mm long and loosely flowered, staminate glumes ovate with green middle vein and apex rounded, pistillate glumes ovate-lanceolate ca. 6 mm and middle vein excurrent into a short awn for ca. 2 mm, perigynia fusiform and glabrous, nutlet brown to dark brown and ovate-rhomboid, nutlet ca. 7 mm long and with a short curved beak.

Lectotypification of Carex buekii (Cyperaceae)

Carex buekii Wimmer (1852: 83) is the name currently applied to a species belonging to Carex sect. Phacocystis Dumortier (1827:146) (Cyperaceae) that occurs throughout Central-Eastern Europe to SW Asia (Chater 1980, Egorova 1999, Jiménez-Mejías & Luceño 2011a, 2011b, Koopman 2011).

Antracoidea vankyi (Ustilaginomycetes) in Poland, with a review of its host spectrum and world distribution

<em>Anthracoidea vankyi</em> Nannf. on <em>Carex muricata</em> L. is confirmed in Poland. The 1919 collection by Käthe Hoffmann from Góry Wałbrzyskie Mts in the Sudets is the only in the country. The fungus is described, and the symptoms of infection plus morphology and ultrastructure of spores arc fully illustrated. The host spectrum and global distribution of <em>Anthracoidea vankyi</em> are reviewed. It is shown that thc fungus parasitizes reprcscntatives of Carex sect. <em>Phaestoglochin</em>, and with some doubts, <em>Carex</em> sect. <em>Vulpinae</em>. It is known from Europe and Asia, but is very likely that it also occurs in North America.

Carex xerophila(Cyperaceae), a New Sedge from the Chaparral of Northern California

Carex xerophila Janeway & Zika is described from gabbro and serpentine soils on the west slope of the northern Sierra Nevada in California. It is documented from four populations in or on the margins of chaparral and open forest. The new species is assigned to Carex section Acrocystis Dumort., and a key is provided for all California representatives of the section. Carex xerophila differs from C. globosa Boott in its uniformly short, erect basal peduncles and Sierra foothills habitats. Carex xerophila differs from C. brainerdii Mack. by its green leaves that are not densely papillose below, its relatively shorter perigynium beaks, and its lower elevation montane habitats. Carex xerophila has more strongly nerved scales and perigynium faces than C. rossii Boott.

Carex diaoluoshanica (Carex sect. Lageniformes, Cyperaceae), a new species from Hainan, China.

Carex diaoluoshanica, a new species of Carex sect. Lageniformes from Hainan, China, is described and illustrated. The new species is similar to C. breviscapa but differs in having wider leaves with the leaf base gradually narrowed, 5–10 cm long and petiolelike, culms subfiliform, with only two spikes, the lateral female spikes from near the culm base.

Parallel and convergent diversification in two northern hemispheric species-rich Carex lineages (Cyperaceae)

Carex species are dominant and abundant plants in boreal and arctic landscapes, typically covering large wetland areas. Most of these vegetation-characteristic species are from Carex sections Phacocystis and Vesicariae, frequently growing together, but also forming monodominant stands. Here we study these species in a phylogenetic framework to infer whether this co-occurrence pattern results from convergent evolution. In both sections, we observed a Northern clade consisting only of arctic to boreal species, a Mixed clade of northern and more southerly distributed species and a Southern grade of species mainly from temperate or further southern zones. The species of the Northern clades of both sections that are the focus of the study may be of similar young age and are rather equally diversified in terms of molecular divergence and morphology, suggesting a replicate adaptive radiation in boreal to arctic habitats. Morphological characters possibly linked with functional importance are not significantly different between the respective clades of the two sections, whereas reproductive structures may be phylogenetically constrained. The evolution of salt tolerance and ongoing diversification in the Northern clade of sect. Phacocystis suggests that the observed replicate adaptive radiation might be a transitional state in the diversification of species and may explain why such radiations are so rarely documented.

Nutlet micromorphology ofCarexsectionRhomboidales sensu Kükenthal (Cyperaceae) and its systematic implications

The sectional delimitation of Carex section Rhomboidales sensu Kükenthal (1909) is problematic and, here, we provide contributions to a systematic understanding of nutlet micromorphology in section Rhomboidales. Nutlet micromorphology of 87 samples representing 71 taxa was investigated using scanning electron microscopy and nine nutlet types were recognized. Although some closely related taxa show similarities, nutlet morphology in section Rhomboidales is stable at the species level and is reliable for species identification. Based on the nutlet characters, section Rhomboidales is delimited and emended as having nutlet rhombic–ovoid, trigonous; beaks conspicuous, erect, rarely curved or coiled; periclinal walls of epidermal cells straight, with zero to two silica bodies. The species with nutlets of the C. harlandii-type and C. thibetica-type are included, and species of the C. chinensis-type and C. macrandrolepsis-type are ascribed to section Mitratae and section Infossae, respectively. Carex longirostrata and C. pseudolongirostrata (= C. nodaeana), formerly ascribed to section Careyanae or section Depauperatae, are well supported as members of section Rhomboidales.

Epitypification Carex bolanderi (Cyperaceae)

With the description of Carex infirminervia Naczi (in Naczi et al. 2002: 528) and the summation of Carex sect. Deweyanae (Tuckerman ex Mackenzie 1913: 352) Mackenzie (1931: 114) by Naczi (in Naczi 2002: 321–325), a recent summary of Pacific Northwest sedges (Wilson et al. 2008: 106–107), and the new Jepson Manual (Zika et al. 2012: 1322), the circumscription of C. bolanderi Olney (1868: 393) is now firmly established. As such, C. bolanderi occurs from southern British Columbia to southern California east to Montana, Utah and New Mexico, and then south in the Sierra Madre Occidental through Chihuahua to northern Durango, Mexico. Previous usage of C. bolanderi was somewhat confused both as to its circumscription and to its distribution because of the inclusion of some specimens of C. infirminervia as in the cases of Munz (1959: 1443, 1974: 887) and Mastrogiuseppe (1993: 1122), or when it was included in C. deweyana Schweinitz (1824: 65; e.g., Cronquist 1969: 261, 1977: 158, Taylor 1983: 102).

Toward an accurate taxonomic interpretation ofCarexfossil fruits (Cyperaceae): A case study in sectionPhacocystisin the Western Palearctic

Despite growing interest in the systematics and evolution of the hyperdiverse genus Carex, few studies have focused on its evolution using an absolute time framework. This is partly due to the limited knowledge of the fossil record. However, Carex fruits are not rare in certain sediments. We analyzed carpological features of modern materials from Carex sect. Phacocystis to characterize the fossil record taxonomically. We studied 374 achenes from modern materials (18 extant species), as well as representatives from related groups, to establish the main traits within and among species. We also studied 99 achenes from sediments of living populations to assess their modification process after decay. Additionally, we characterized 145 fossil achenes from 10 different locations (from 4-0.02 mya), whose taxonomic assignment we discuss. Five main characters were identified for establishing morphological groups of species (epidermis morphology, achene-utricle attachment, achene base, style robustness, and pericarp section). Eleven additional characters allowed the discrimination at species level of most of the taxa. Fossil samples were assigned to two extant species and one unknown, possibly extinct species. The analysis of fruit characters allows the distinction of groups, even up to species level. Carpology is revealed as an accurate tool in Carex paleotaxonomy, which could allow the characterization of Carex fossil fruits and assign them to subgeneric or sectional categories, or to certain species. Our conclusions could be crucial for including a temporal framework in the study of the evolution of Carex.

The identity of Cintractia carpophila var. kenaica: reclassification of a North American smut on Carex micropoda as a distinct species of Anthracoidea

Cintractia carpophila var. kenaica, a neglected taxon described from Alaska more than half a century ago, is re-described and illustrated. Its nomenclature and taxonomic status are discussed. This smut species is characterised by small spores with a very finely verruculose surface rarely enclosed by a thin, hyaline, mucilaginous sheath, a wall with 2-5 distinct internal swellings, and parasitism on Carex micropoda (Carex sect. Dornera). It is reallocated to the genus Anthracoidea as a distinct species, Anthracoidea kenaica comb. nov., and assigned to Anthracoidea section Leiosporae which includes species having smooth or very finely verruculose spores. Morphological and biological characteristics of the five most similar Anthracoidea species are contrasted and discussed.

Molecular and morphological evidence for a new species from South Africa: Carex rainbowii (Cyperaceae)

Carex rainbowii (Cariceae, Cyperaceae), a new species from the Drakensberg mountains (KwaZulu-Natal province), is described and illustrated. It was found in the shady understory of the Afromontane forest in the Cathedral Peak area. An additional, nearby population was also identified based on previously collected herbarium material. Morphological and molecular (cpDNA 5′trnK intron and nrDNA ITS and ETS sequences) data were used to evaluate the taxonomic status of these populations and shed light on their systematic placement. Our data strongly support their taxonomic identity and inclusion in Carex sect. Sylvaticae. The new species can be readily distinguished from other related taxa mainly by the frequently androgynecandrous terminal spike, dense female spikes, hyaline glumes, as well as by some quantitative features. This finding implies a considerable biogeographic disjunction from the mainly Eurasian-North African range of the remaining species of sect. Sylvaticae, a pattern also found in the related sections Ceratocystis, Rhynchocystis and Spirostachyae. Comments are provided on previous misidentifications of C. rainbowii as the closely related Carex sylvatica. Data pertinent to the conservation status of the species are provided.

<I>Carex viridistellata</I> sp. nov. (Cyperaceae), a New Cryptic Species from Prairie Fens of the Eastern United States

Divergence between evolutionary lineages is not always marked by the development of obvious species-specific characters, whether morphological, physiological, or ecological. Consequentially, extant biodiversity can easily be overlooked. These cryptic species are often not recognized until genetic data are in hand, as is the case for the novel taxon we describe here. Carex viridistellata in Carex section Ceratocystis is an endemic species restricted to calcareous wetlands of Michigan, Ohio, and Indiana, where it has previously been collected as Carex cryptolepis. Crosses between Carex viridistellata and Carex cryptolepis produce sterile F1 hybrids, and the two species are differentiated by a number of subtle morphological characters, as well as aspects of their respective ecologies. Phylogenetic analyses of nrDNA strongly indicate monophyly of Carex viridistellata and its sister species relationship with the North Carolina narrow endemic Carex lutea. Both species constitute a distinct lineage within a generally poorly resolved section Ceratocystis. This work highlights the broad importance of cryptic taxa, with implications for fields ranging from population genetics to conservation and restoration.