Taxonomic revision of the tropical African group of Carex subsect. Elatae (sect. Spirostachyae, Cyperaceae)

The tropical African monophyletic group of Carex subsect. Elatae (sect. Spirostachyae) is distributed in continental tropical Africa, Madagascar, the Mascarene archipelago, and Bioko Island (32 km off the coast of West Africa, in the Gulf of Guinea). The first monographic treatment of this Carex group, as well as of the tribe Cariceae, was published by Kükenthal (as sect. Elatae Kük.). Recently, the first molecular (nrDNA, cpDNA) phylogeny of Carex sect. Elatae has been published, which also included the species of sect. Spirostachyae. In the resulting consensus trees, most species of sect. Elatae were embedded within core Spirostachyae and so this section was joined with sect. Spirostachyae as subsect. Elatae. Within subsect. Elatae, several groups were described, one of which was termed the “tropical African group”. Here we present a taxonomic revision of this group, based on more than 280 vouchers from 29 herbaria as well as in field trips in Tropical Africa. In the revision, we recognise 12 species (16 taxa) within the tropical African group, and so have somewhat modified our previous view, in which 10 species, 12 taxa were listed. One new species from Tanzania is included in this treatment, C. uluguruensis Luceño & M. Escudero. Several combinations are made, C. cyrtosaccus is treated as a synonym of C. vallis-rosetto and, finally, the binomial C. greenwayi has been recognised.Las especies de la subsección Elatae (sección Spirostachyae) del género Carex que se distribuyen por África tropical continental, Madagascar, el archipiélago de las Mascareñas y la isla de Bioko (a 32 km del litoral de África occidental, en el golfo de Guinea) forman un grupo monofilético. El primer tratamiento taxonómico de este grupo de cárices, así como de la tribu Cariceae en su conjunto, fue elaborado por Kükenthal (sección Elatae Kük.); recientemente, se ha publicado el primer estudio de filogenia mo - lecular (nrDNA, cpDNA) de los táxones de este grupo, junto con la inmensa mayoría de las restantes especies que Kükenthal incluyó en las secciones Elatae y Spirostachyae. Salvo escasas excepciones, los táxones incluidos se agruparon en un clado (“core Spirostachyae”) que contiene las especies de las dos secciones antes aludidas. En congruencia con estos resultados, la sección Elatae fue incluida en la sección Spirostachyae como susbsección Elatae. Dentro de dicha subsección se observaron varios clados; uno de ellos, el denominado “grupo de África tropical”, es el objeto del presente trabajo, en el que presentamos una revisión taxonómica basada en el estudio de más de 280 pliegos conservados en 29 herbarios, así como en trabajos de campo llevados a cabo en África tropical. Como resultado del análisis de dichos materiales hemos realizado una profunda reorganización taxonómica, fruto de la cual admitimos 12 especies (16 táxones) dentro del grupo de África tropical. Se describe además una nueva especie del NE de Tanzania, C. uluguruensis Luceño & M. Escudero. Asimismo, se llevan a cabo varias combinaciones nomenclaturales, el nombre de C. cyrtosaccus es considerado sinónimo de C. vallis-rosetto, y se reconoce el binomio C. grennwa

Carex modesti (Cyperaceae), a new species from southern Tanzania

A new species of Carex (Cyperaceae), Carex modesti, is described from southern Tanzania. It grows on stream sides and peat bogs at about 2750 m in the Kitulo Plateau. It is morphologically distinct from the similar species C. vallis-rosetto by its creeping rhizomes, coriaceous leaves and solitary spikes arising in each node. Carex modesti is included in Carex sect. Spirostachyae subsect. Elatae together with other Carex species from the tropical African mountain

Carex modesti (Cyperaceae), a new species from southern Tanzania

A new species of Carex (Cyperaceae), Carex modesti, is described from southern Tanzania. It grows on stream sides and peat bogs at about 2750 m in the Kitulo Plateau. It is morphologically distinct from the similar species C. vallis-rosetto by its creeping rhizomes, coriaceous leaves and solitary spikes arising in each node. Carex modesti is included in Carex sect. Spirostachyae subsect. Elatae together with other Carex species from the tropical African mountain

Typification of Carex helodes Link, Carex laevigata Sm. and Carex patula Link ex Schkuhr (Cyperaceae)

The name of Carex helodes Link is neotypified. This species has been erroneously considered as a synonym of Carex laevigata Sm. and Carex patula Schkuhr, which the names are also lectotypified. Each type is illustrated and discussed.Le nom de Carex helodes Link est néotypifié. Cette espèce a été considérée de manière erronée comme un synonyme de Carex laevigata Sm. et Carex patula Schkuhr dont les noms sont aussi lectotypifiés. Chaque type est illustré et discuté

Cryptic species due to hybridization: A combined approach to describe a new species (carex: Cyperaceae)

Disappearance of diagnostic morphological characters due to hybridization is considered to be one of the causes of the complex taxonomy of the species-rich (ca. 2000 described species) genus Carex (Cyperaceae). Carex furva s.l. belongs to section Glareosae. It is an endemic species from the high mountains of the Iberian Peninsula (Spain and Portugal). Previous studies suggested the existence of two different, cryptic taxa within C. furva s.l. Intermediate morphologies found in the southern Iberian Peninsula precluded the description of a new taxa. We aimed to determine whether C. furva s.l. should be split into two different species based on the combination of morphological and molecular data. We sampled ten populations across its full range and performed a morphological study based on measurements on herbarium specimens and silica-dried inflorescences. Both morphological and phylogenetic data support the existence of two different species within C. furva s.l. Nevertheless, intermediate morphologies and sterile specimens were found in one of the southern populations (Sierra Nevada) of C. furva s.l., suggesting the presence of hybrid populations in areas where both supposed species coexist. Hybridization between these two putative species has blurred morphological and genetic limits among them in this hybrid zone. We have proved the utility of combining molecular and morphological data to discover a new cryptic species in a scenario of hybridization. We now recognize a new species, C. lucennoiberica, endemic to the Iberian Peninsula (Sierra Nevada, Central system and Cantabrian Mountains). On the other hand, C. furva s.s. is distributed only in Sierra Nevada, where it may be threatened by hybridization with C. lucennoiberica. The restricted distribution of both species and their specific habitat requirements are the main limiting factors for their conservation

Niche shifts after long-distance dispersal events in bipolar sedges (Carex, Cyperaceae)

PREMISE OF THE STUDY: Bipolar species represent the greatest biogeographical disjunction on Earth, raising many questions about the colonization and adaptive processes behind such striking distribution. We investigated climatic niche differences of five Carex bipolar species in North and South America to assess niche shifts between these two regions. Moreover, we assessed potential distribution changes with future climate change. METHODS: We used 1202 presence data points from herbarium specimens and 19 bioclimatic variables to assess climatic niche differences and potential distributions among the five species using ordination methods and Maxent. KEY RESULTS: The niche overlap analyses showed low levels of niche filling and high climatic niche expansion between North and South America. Carex macloviana and C. maritima showed the greatest niche expansion (60% and 96%, respectively), followed by C. magellanica (45%) and C. microglochin (39%). Only C. canescens did not colonize new environments (niche expansion = 0.2%). In contrast, all species but C. magellanica had niche filling that was <40%; hence, they are absent in the south from many environments they inhabit in North America. Climate change will push all species toward higher latitudes and elevation, reducing the availability of suitable environments. CONCLUSIONS: The colonization of South America seems to have involved frequent climatic niche shifts. Most species have colonized new environments from those occupied in the North. Observed niche shifts appear congruent with time since colonization and with current genetic structure within species. In these cold-dwelling species, climate change will most likely decrease their suitable environments in the future.Ministerio de Economía y Competitividad CGL2012-3874, CGL2016-77401-

Hallazgo de dos nuevas poblaciones sevillanas de Carex helodes: una especie declarada extinta de la flora española

Carex helodes Link fue durante muchos años una especie ignorada por la inmensa mayoría de los autores debido a su confusión con C. laevigata. Más recientemente se realizaron estudios biosistemáticos que no dejan lugar a dudas sobre el valor taxonómico de C. helodes . Su área de distribución conocida se restringía al sur de Portugal y a la localidad sevillana de El Ronquillo (Luceño, 1992); sin embargo, recientemente se han hallado algunas pequeñas poblaciones próximas entre sí en el norte de Marruecos

Notas sobre Neófitos en el curso urbano del río Guadalquivir en Sevilla

El asentamiento y expansión de especies vegetales en regiones fuera de su área de distribución natural por causas antrópicas, es uno de los problemas más importantes que afectan a la conservación de la biodiversidad. Las especies alóctonas suponen una grave amenaza para la fl ora autóctona, ya que pueden alterar la dinámica natural de los ecosistemas (Azolla fi liculoides; García Murillo & al., 2007), desplazar por competencia a las especies nativas (Oxalis pes-caprae; Vilà & al., 2006), o provocar problemas de introgresión genética en las mismas (Ulmus; Zalapa & al., 2009; revisión en Largiadèr, 2008). Por ello, existen numerosos programas gubernamentales que tratan de reducir el impacto negativo de la fl ora invasora sobre la nativa mediante su erradicación o control (Carpobrotus edulis; Kelly & Maguire, 2009). Así, el estudio de la fl ora alóctona en nuestro país es una tarea que suscita cada vez mayor interés. A las revisiones nacionales de especies naturalizadas de Sanz Elorza & al. (2001) y Dana & al. (2004) se le suman multitud de trabajos más recientes de carácter más local que contribuyen al conocimiento y seguimiento de este problema (e.g.: Sanz Elorza & al., 2005; Pyke, 2008; Solanas & Pérez Latorre, 2008). Los cauces fl uviales en sentido amplio son uno de los ecosistemas más afectados por el problema de las especies alóctonas en nuestro país (Dana & al., 2004). El mantenimiento de áreas libres (con un mayor o menor grado de naturalidad) en los márgenes de los ríos, les permite actuar como corredores biológicos que facilitan el movimiento y dispersión de especies (Rosenberg & al., 1997). Esta característica, aprovechada en la gestión de la biodiversidad para conectar espacios naturales distantes, puede ser también empleada por las especies invasoras para dispersarse más fácilmente. El caso del Guadalquivir a su paso por Sevilla suscita interés ya que a menos de 60 km aguas abajo se halla el Parque Nacional de Doñana, cuyo extraordinario valor biológico es bien conocido. En el presente trabajo damos constancia y comentamos la presencia de algunas especies alóctonas naturalizadas que hemos observado en el tramo urbano de la dársena del río Guadalquivir a su paso por Sevilla. Materiales testigo de cada una de las especies comentadas han sido depositados en el herbario de la Universidad Pablo de Olavide de Sevilla (UPOS)

Genomic Hotspots of Chromosome Rearrangements Explain Conserved Synteny Despite High Rates of Chromosome Evolution in a Holocentric Lineage

Holocentric organisms, unlike typical monocentric organisms, have kinetochore activity distributed along almost the whole length of the chromosome. Because of this, chromosome rearrangements through fission and fusion are more likely to become fixed in holocentric species, which may account for the extraordinary rates of chromosome evolution that many holocentric lineages exhibit. Long blocks of genome synteny have been reported in animals with holocentric chromosomes despite high rates of chromosome rearrangements. Nothing is known from plants, however, despite the fact that holocentricity appears to have played a key role in the diversification of one of the largest angiosperm genera, Carex (Cyperaceae). In the current study, we compared genomes of Carex species and a distantly related Cyperaceae species to characterize conserved and rearranged genome regions. Our analyses span divergence times ranging between 2 and 50 million years. We also compared a C. scoparia chromosome-level genome assembly with a linkage map of the same species to study rearrangements at a population level and suppression of recombination patterns. We found longer genome synteny blocks than expected under a null model of random rearrangement breakpoints, even between very distantly related species. We also found repetitive DNA to be non-randomly associated with holocentromeres and rearranged regions of the genome. The evidence of conserved synteny in sedges despite high rates of chromosome fission and fusion suggests that conserved genomic hotspots of chromosome evolution related to repetitive DNA shape the evolution of recombination, gene order and crossability in sedges. This finding may help explain why sedges are able to maintain species cohesion even in the face of high interspecific chromosome rearrangements.Ministerio de Educación CAS19/00294Ministerio de Ciencia e Innovación PGC2018- 099608-B-100, PID2021-122715NB-I00Swiss National Science Foundation PCEFP3_20286

Isolation of 91 polymorphic microsatellite loci in the western mediterranean endemic carex helodes (Cyperaceae)

Premise of the study: Microsatellite primers were developed for Carex helodes (Cyperaceae), a western Mediterranean endemic that is locally distributed in southern Portugal and southwestern Spain and rare in northern Morocco. Methods and Results: One hundred nine nuclear microsatellite markers were developed using a shotgun pyrosequencing method, resulting in 91 polymorphic and 18 monomorphic loci when tested using 19 individuals sampled from five populations from Portugal, Spain, and Morocco. Loci averaged 3.23 alleles per locus (SD = 1.15). In a single population (Cortelha population, Portugal), the 34 most polymorphic loci showed a mean observed heterozygosity of 0.357 (SD = 0.292) and mean expected heterozygosity of 0.384 (SD = 0.255). Conclusions: Next-generation sequencing allowed us to develop a high number of genetic markers with levels of polymorphism adequate to study gene flow among populations. However, when genotyping the individuals within a population, we found low levels of variation