This study presents a preliminary list of 161 species from the genus Quercus, all native to Mexico. These species belong to three sections: section Lobatae (red oaks, 76 species), Quercus (white oaks, 81 species), and Protobalanus (intermediate oaks, 4 species). It is estimated that 109 are endemic to Mexico, 47 of which belong to section Quercus, 61 to section Lobatae, and 1 to section Protobalanus. Of all the oak species found in Mexico, 33 of them extend their range into the United States, while only 20 are also found in Central America. The states with the greatest oak divesity are Oaxaca, Nuevo Leon, Jalisco, Chihuahua and Veracruz. Species widely distributed in Mexico are Q. candicans, Q. castanea, Q. crassifolia, Q. laeta, Q. microphylla, Q. obtusata and Q. rugosa. In general, Mexican oak species grow in elevations ranging form 0 to 3,500 m; however, they are found predominantly between 1,000 and 3,000 m. Knowledge on the taxonomy of Mexican oak species remains incomplete; therefore, further research is needed around this important genus.

/pdf/diversidad-del-genero-quercus-fagaceae-en-mexico-2s56dsoqr8.pdf

Diversidad del género Quercus (Fagaceae) en México

In this chapter, we review major classification schemes proposed for oaks by John Claudius Loudon, Anders Sandoe Orsted, William Trelease, Otto Karl Anton Schwarz, Aimee Antoinette Camus, Yuri Leonardovich Menitsky, and Kevin C. Nixon. Classifications of oaks (Fig. 2.1) have thus far been based entirely on morphological characters. They differed profoundly from each other because each taxonomist gave a different weight to distinguishing characters; often characters that are homoplastic in oaks. With the advent of molecular phylogenetics our view has considerably changed. One of the most profound changes has been the realisation that the traditional split between the East Asian subtropical to tropical subgenus Cyclobalanopsis and the subgenus Quercus that includes all other oaks is artificial. The traditional concept has been replaced by that of two major clades, each comprising three infrageneric groups: a Palearctic-Indomalayan clade including Group Ilex (Ilex oaks), Group Cerris (Cerris oaks) and Group Cyclobalanopsis (cycle-cup oaks), and a predominantly Nearctic clade including Group Protobalanus (intermediate or golden cup oaks), Group Lobatae (red oaks) and Group Quercus (white oaks, with most species in America and some 30 species in Eurasia). In addition, recent phylogenetic studies identified two distinct clades within a wider group of white oaks: the Virentes oaks of North America and a clade with two disjunct endemic species in western Eurasia and western North America, Quercus pontica and Q. sadleriana. The main morphological feature characterising these phylogenetic lineages is pollen morphology, a character overlooked in traditional classifications. This realisation, along with the now available (molecular-)phylogenetic framework, opens new avenues for biogeographic, ecological and evolutionary studies and a re-appraisal of the fossil record. We provide an overview about recent advances in these fields and outline how the results of these studies contribute to the establishment of a unifying systematic scheme of oaks. Ultimately, we propose an updated classification of Quercus recognising two subgenera with eight sections. This classification considers morphological traits, molecular-phylogenetic relationships, and the evolutionary history of one of the most important temperate woody plant genera.

https://www.biorxiv.org/content/biorxiv/early/2017/07/31/168146.full.pdf

An Updated Infrageneric Classification of the Oaks: Review of Previous Taxonomic Schemes and Synthesis of Evolutionary Patterns

A Phylogenetic Perspective on the Distribution of Plant Diversity

The tree of life is highly reticulate, with the history of population divergence emerging from populations of gene phylogenies that reflect histories of introgression, lineage sorting and divergence. In this study, we investigate global patterns of oak diversity and test the hypothesis that there are regions of the oak genome that are broadly informative about phylogeny. We utilize fossil data and restriction-site associated DNA sequencing (RAD-seq) for 632 individuals representing nearly 250 Quercus species to infer a time-calibrated phylogeny of the world's oaks. We use a reversible-jump Markov chain Monte Carlo method to reconstruct shifts in lineage diversification rates, accounting for among-clade sampling biases. We then map the > 20 000 RAD-seq loci back to an annotated oak genome and investigate genomic distribution of introgression and phylogenetic support across the phylogeny. Oak lineages have diversified among geographic regions, followed by ecological divergence within regions, in the Americas and Eurasia. Roughly 60% of oak diversity traces back to four clades that experienced increases in net diversification, probably in response to climatic transitions or ecological opportunity. The strong support for the phylogeny contrasts with high genomic heterogeneity in phylogenetic signal and introgression. Oaks are phylogenomic mosaics, and their diversity may in fact depend on the gene flow that shapes the oak genome.

https://nph.onlinelibrary.wiley.com/doi/epdf/10.1111/nph.16162

Genomic landscape of the global oak phylogeny

Contents Summary 669 I. Model clades for the study and integration of ecology and evolution 670 II. Oaks: an important model clade 671 III. Insights from the history of the American oaks for understanding community assembly and ecosystem dominance 673 IV. Bridging the gap between micro- and macroevolutionary processes relevant to ecology 679 V. How do we reconcile evidence for adaptive evolution with niche conservatism and long-term stasis? 682 VI. High plasticity and within-population genetic variation contribute to population persistence 683 VII. Emerging technologies for tracking functional change 685 VIII. Conclusions 685 Acknowledgements 686 References 686 SUMMARY: Ecologists and evolutionary biologists are concerned with explaining the diversity and composition of the natural world and are aware of the inextricable linkages between ecological and evolutionary processes that maintain the Earth's life support systems. Yet examination of these linkages remains challenging due to the contrasting nature of focal systems and research approaches. Model clades provide a critical means to integrate ecology and evolution, as illustrated by the oaks (genus Quercus), an important model clade, given their ecological dominance, remarkable diversity, and growing phylogenetic, genomic, and ecological data resources. Studies of the clade reveal that their history of sympatric parallel adaptive radiation continues to influence community assembly today, highlighting questions on the nature and extent of coexistence mechanisms. Flexible phenology and hydraulic traits, despite evolutionary stasis, may have enabled adaptation to a wide range of environments within and across species, contributing to their high abundance and diversity. The oaks offer fundamental insights at the intersection of ecology and evolution on the role of diversification in community assembly processes, on the importance of flexibility in key functional traits in adapting to new environments, on factors contributing to persistence of long-lived organisms, and on evolutionary legacies that influence ecosystem function.

https://nph.onlinelibrary.wiley.com/doi/epdf/10.1111/nph.15450

Diversification, adaptation, and community assembly of the American oaks (Quercus), a model clade for integrating ecology and evolution

Summary
Oaks (Quercus, Fagaceae) are the dominant tree genus of North America in species number and biomass, and Mexico is a global center of oak diversity. Understanding the origins of oak diversity is key to understanding biodiversity of northern temperate forests.
A phylogenetic study of biogeography, niche evolution and diversification patterns in Quercus was performed using 300 samples, 146 species. Next-generation sequencing data were generated using the restriction-site associated DNA (RAD-seq) method. A time-calibrated maximum likelihood phylogeny was inferred and analyzed with bioclimatic, soils, and leaf habit data to reconstruct the biogeographic and evolutionary history of the American oaks.
Our highly resolved phylogeny demonstrates sympatric parallel diversification in climatic niche, leaf habit, and diversification rates. The two major American oak clades arose in what is now the boreal zone and radiated, in parallel, from eastern North America into Mexico and Central America.
Oaks adapted rapidly to niche transitions. The Mexican oaks are particularly numerous, not because Mexico is a center of origin, but because of high rates of lineage diversification associated with high rates of evolution along moisture gradients and between the evergreen and deciduous leaf habits. Sympatric parallel diversification in the oaks has shaped the diversity of North American forests.

https://nph.onlinelibrary.wiley.com/doi/pdf/10.1111/nph.14773

Sympatric parallel diversification of major oak clades in the Americas and the origins of Mexican species diversity

SE HIZO UN ESTUDIO FLORISTICO DE LA PORCION GUERRERENSE DE LA SIERRA DE TAXCO, LA CUAL INCLUYE UN AREA DE 730 KM2 Y SE UBICA EN LOS MUNICIPIOS DE TETIPAC, PILCAYA, TAXCO DE ALARCON, IXCATEOPAN DE CUAUHTEMOC Y PEDRO ASCENCIO ALQUISIRAS. SE GENERO UNA BASE DE DATOS QUE CONTIENE 4 139 REGISTROS. SE CITAN 1 384 ESPECIES, 570 GENEROS Y 150 FAMILIAS DE PLANTAS VASCULARES, ASI COMO CINCO TIPOS DE VEGETACION PRINCIPALES: BOSQUE TROPICAL CADUCIFOLIO, BOSQUE DE QUERCUS (INCLUYENDO ASOCIACIONES CON CONIFERAS), BOSQUE DE CONIFERAS, BOSQUE MESOFILO DE MONTANA Y BOSQUE DE GALERIA. LAS FAMILIAS MAS REPRESENTATIVAS SON ASTERACEAE (209 ESPECIES Y 79 GENEROS), FABACEAE (152 Y 50) Y POACEAE (80 Y 39).

Flora vascular de la porción guerrerense de la Sierra de Taxco, Guerrero, México

Flora vascular de la porción guerrerense de la Sierra de Taxco, Guerrero ,México

SE ANALIZA LA FLORA VASCULAR DE PAPALUTLA, GRO. Y SUS ALREDEDORES, EN LA REGION ORIENTAL DE LA CUENCA DEL RIO BALSAS, EN UNA AREA DE 30 KM 2 . SE ENCONTRARON 699 ESPECIES Y VARIEDADES, 375 GENEROS Y 96 FAMILIAS, EN DOS TIPOS DE VEGETACION: BOSQUE DE QUERCUS Y BOSQUE TROPICAL CADUCIFOLIO, SIENDO ESTE ULTIMO EL DE MAYOR EXTENSION.

Flora de Papalutla, Guerrero y de sus alrededores

A nomenclatural conflict between Quercus acutifolia and Q. conspersa is solved based on the thorough revision of herbarium specimens, type specimens, original descriptions and field observations. Q. conspersa is proposed as a synonym of Q. acutifolia , as are the names Q. acutifolia ζ conspersa , Q. acutifolia β bonplandi , Q. acutifolia γ angustifolia , Q. acutifolia e longifolia and Q. candolleana. In addition, Q. grahamii is recognized as the correct name for the taxon identified  as Q. acutifolia . Q. conspersa is lectotypified and Q. conspersa f. caudata is neotypified here. Information on the distribution of Q. acutifolia and Q. grahamii and the main features used to distinguish them is also provided.

/pdf/a-nomenclatural-revision-of-quercus-acutifolia-q-conspersa-2c5r6d2tgg.pdf

Susana Valencia Ávalos

Papers

Sympatric parallel diversification of major oak clades in the Americas and the origins of Mexican species diversity

Flora vascular de la porción guerrerense de la Sierra de Taxco, Guerrero, México

Flora vascular de la porción guerrerense de la Sierra de Taxco, Guerrero ,México

Flora de Papalutla, Guerrero y de sus alrededores

A nomenclatural revision of Quercus acutifolia , Q. conspersa and Q. grahamii ( Lobatae , Fagaceae)