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Riella (Riellaceae) is a genus of rare, ephemeral, aquatic liverworts that includes some taxa specialized in growing submerged in brackish, seasonal water ponds and lagoons. One of these species, Riella helicophylla is the type of the genus. Apart from being of conservation concern, it has been used as a model organism for cytological and physiological processes. The species was described from Algeria in the mid‐nineteenth century and was not found elsewhere for almost a century, when it was discovered in central Spain. Nonetheless, those new populations were considered morphologically different and served to describe a new variety (var. macrocarpa), and a form (f. latealata) of the latter. The number of population records increased considerably in the following decades, especially in the late twentieth century; at the same time, it was discovered in several countries throughout the Mediterranean basin. Those reports, however, did not account for its infraspecific distinction. As part of a broader study of the genus, in this work, we have revisited the taxonomy of R. helicophylla based on an integrative approach considering morphological and molecular DNA sequence data. Our broadly sampled study revealed that R. helicophylla includes two morphotypes corresponding with the previously recognized varieties of this species. These varieties differ consistently in a number of morphological gametophytic and spore traits. Riella helicophylla was resolved as paraphyletic in phylogenies based on nuclear and plastid DNA sequences. The accessions clustered in two monophyletic clades in concert with morphology, supporting their recognition at the species level. Accordingly, a new combination is proposed, R. macrocarpa, which includes the neglected R. helicophylla var. macrocarpa and R. helicophylla var. macrocarpa f. latealata. Lectotypes are designated for the two latter taxa and for R. helicophylla. The two species are fully described and illustrated, and an updated identification key of the Mediterranean species is included. Updated information on the conservation status of both species is provided. [ABSTRACT FROM AUTHOR]

Aim Dioscorea (Dioscoreaceae) is a predominantly pantropical genus (< 600 species) that includes the third most important tropical tuber crop and species of pharmacological value. Fossil records from both the Northern and Southern Hemispheres were used to test hypotheses about the origin of the genus Dioscorea, and to examine potential macroevolutionary processes that led to its current distribution. Location Pantropical distribution. Methods Divergence times were estimated using the most comprehensive phylogeny of the group published to date based on plastid sequences and fossil calibrations, applying a relaxed-clock model approach. Ancestral areas and range shifts were reconstructed using time-stratified likelihood-based models, reflecting past continental connectivity and biogeographical models incorporating the spatial range of fossils. Results Fossil-informed biogeographical analysis supported colonization of the Nearctic by ancient yam lineages from the western Palaearctic and subsequent migration to the South. Most of the pantropical South American, African and Southeast Asian lineages experienced a relatively recent diversification in the Oligocene-Miocene. Long-distance dispersals were inferred for the colonizations of the New World, Africa and Madagascar. Main conclusions Dioscorea likely originated between the Late Cretaceous and the Early Eocene in the Laurasian Palaearctic, followed by possible dispersal to South America via the Eocene North Atlantic Land Bridge. [ABSTRACT FROM AUTHOR]

Aim The Chilean endemic Dioscorea biloba (Dioscoreaceae) is a dioecious geophyte that shows a remarkable 600 km north-south disjunction in the peripheral arid area of the Atacama Desert. Its restricted present-day distribution and probable Neogene origin indicate that its populations have a history linked to that of the Atacama Desert, making this an ideal model species with which to investigate the biogeography of the region. Location Chile, Atacama Desert and peripheral arid area. Methods Two hundred and seventy-five individuals from nine populations were genotyped for seven nuclear microsatellite loci, and plastid trnL-F and trnT-L sequences were obtained for a representative subset of these. Analyses included the estimation of genetic diversity and population structure through clustering, Bayesian and analysis of molecular variance analyses, and statistical parsimony networks of chloroplast haplotypes. Isolation by distance was tested against alternative dispersal hypotheses. Results Microsatellite markers revealed moderate to high levels of genetic diversity within populations, with those from the southern Limarí Valley showing the highest values and northern populations showing less exclusive alleles. Bayesian analysis of microsatellite data identified three genetic groups that corresponded to geographical ranges. Chloroplast phylogeography revealed no haplotypes shared between northern and southern ranges, and little haplotype sharing between the two neighbouring southern valleys. Dispersal models suggested the presence of extinct hypothetical populations between the southern and northern ranges. Main conclusions Our results are consistent with prolonged isolation of the northern and southern groups, mediated by the life-history traits of the species. Significant isolation was revealed at both large and moderate distances as gene flow was not evident even between neighbouring valleys. Bayesian analyses of microsatellite and chloroplast haplotype diversity identified the southern area of Limarí as the probable area of origin of the species. Our data do not support recent dispersal of D. biloba from the southern range into Antofagasta, but indicate the fragmentation of an earlier wider range, concomitant with the Pliocene-Pleistocene climatic oscillations, with subsequent extinctions of the Atacama Desert populations and the divergence of the peripheral ones as a consequence of genetic drift. [ABSTRACT FROM AUTHOR]

Aim Borderea pyrenaica (Dioscoreaceae) is a Tertiary relict plant endemic to the Central Pyrenees. Because of its narrow distribution in a small geographical area and the fact that it is restricted to high alpine habitats, it constitutes an ideal model species for inferring the historical dynamics of population survival and migration during and after Quaternary glaciations in the Pyrenees. Location Central Pyrenees and pre-Pyrenees, Spain–France. Methods Eleven primer pairs were used to amplify 18 microsatellite loci in this allotetraploid species in a sample of 804 individuals from 15 populations, revealing a total of 77 alleles. Genotypic data of individuals and populations were analysed using clustering and Bayesian methods of analysis of population structure. Results A higher number of private alleles and a significantly higher allelic richness ( A*) were found in the southern area (21, A* = 2.295) than in the northern area (5, A* = 1.791). Furthermore, the allelic composition of the northern area represented a subset of that from the southern area. Main conclusions The hypothesis of in situ survival in northern Pyrenean nunataks was rejected, while peripheral refugia were considered to be restricted to the southern Pyrenees and pre-Pyrenees, where historical geographical fragmentation probably caused the divergence among southern Pyrenean populations. Molecular evidence indicates that these refugial populations probably colonized the northern area after sheet-ice retreat. Borderea pyrenaica lineages followed two migratory pathways in their northward colonization, suggesting several founder events for the populations that eventually reached the territory of the Gavarnie cirque. [ABSTRACT FROM AUTHOR]

Premise of the study: The focus of this study is to develop microsatellite markers in Armeria caespitosa, a narrow endemic of central Spain. Microsatellite loci are sought to clarify population structure and estimate gene flux among populations. Methods and Results: Enriched microsatellite genomic libraries were used for microsatellite isolation. Sixteen microsatellite loci were characterized, eight of which can be used for successful genotyping. Allele number ranged from two to seven per locus. Observed and expected heterozygosity ranged from 0.300 to 0.800 and from 0.296 to 0.733, respectively. Cross-amplication of seven and six loci was successful for A. maritima and A. cantabrica, respectively. Conclusions: These microsatellites are suitable in the study of population genetics and gene flow among A. caespitosa populations. The information provided by these markers may be useful in the study of this plant's response to global warming. [ABSTRACT FROM AUTHOR]

* Premise of the study: Enriched genomic libraries were used to isolate and characterize microsatellite loci in Festuca gautieri, an important plant component of subalpine calcareous grasslands of the eastern Iberian Peninsula, the Pyrenees, and the Cantabrian Mountains. Microsatellites were required to investigate landscape genetics across its distribution range and at a narrower geographical scale within the Ordesa y Monte Perdido, Aigüestortes, and Picos de Europa Spanish national parks. * Methods and Results: Ten polymorphic microsatellite loci were characterized. They amplified a total of 116 alleles in a sample of 30 individuals of F. gautieri, showing high levels of genetic diversity (expected heterozygosity = 0.821). Cross-species transferability to two other close congeners, F. eskia and F x picoeuropeana, increased the total number of alleles to 137. These taxa showed lower numbers of alleles but similar levels of genetic diversity to F. gautieri. * Conclusions: These microsatellite primers will be useful in population and landscape genetics and in establishing conservation strategies for these characteristic elements of subalpine pastures. [ABSTRACT FROM AUTHOR]

Premise of the study: Microsatellite loci were isolated and characterized from enriched genomic libraries of two taxa of the Chilean Epipetrum group of Dioscorea to assess their levels of genetic diversity and population differentiation. Methods and Results: Eleven microsatellite loci were identifi ed. Six out of nine microsatellites from D. biloba amplifi ed in D. humilis , and the two microsatellites from D. humilis amplifi ed in both taxa. Two different sets of eight loci amplifi ed in each of the two tested taxa, D. biloba and D. humilis . The average number of alleles was 5.75 and 5 for D. biloba and D. humilis , respectively. Higher levels of mean genetic diversity were found in D. biloba ( HE = 0.639) than in D. humilis ( HE = 0.414). Conclusions: These microsatellite primers will be useful in population genetic studies and to establish conservation strategies in the endangered taxa of the Epipetrum group of Dioscorea . [ABSTRACT FROM AUTHOR]

The article presents a proposal for the rejection of the Luzuriaga cordata under Dioscoreaceae. It notes that L. Cordata has not been valid in botanical literature because of its overlooked characteristic classified under the family of Dioscoreaceae. It cites name reassessments which show that generic placement of Dioscorea and Epipetrum species are classified under paraphyletic Dioscorea, which is in contrast to the independent monophyletic genus interpreted by other taxonomist.