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

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

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 helodes" Link novedad para el continente africano

Carex helodes Link, perteneciente a la sección Spirostachyae Drejer ex H.L. Bailey (Luceño 1994), ha sido frecuentemente confundida con C. laevigata Sm. (Kükenthal, 1909; Vicioso, 1959). Chater (1980) considera, sin embargo, que son dos especies diferentes, aunque no incluye C. helodes en su monografía europea

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-

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

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