Juan Antonio Devesa
University of Extremadura
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Featured researches published by Juan Antonio Devesa.
Plant Systematics and Evolution | 1999
Josefa López; Tomás Rodríguez-Riaño; Ana Ortega-Olivencia; Juan Antonio Devesa; Trinidad Ruiz
We studied the biology and floral rewards of 34 taxa ofGenisteae from the SW of Europe. Most of the floral attributes show a statistically significant direct relationship. Anther biomass of the lower whorl (lW) is significantly lower than that of the upper whorl (uW), and the ratio of the two (Rv) differs among the taxa. All taxa are polliniferous, andRetama sphaerocarpa also secretes nectar. They can be considered xenogamous or facultative xenogams on the basis of their high pollen/ovule (P/O) ratios. Three principal mechanisms of pollen releasing are identified in this tribe: valvular, pump and explosive; the latter comprises specialized and nonspecialized subtypes. Pollination is sternotribic except in the specialized explosive mechanism, in which it is noto-sternotribic. Thus some pollen serves as food (pollen from the uW, which adheres to the ventral surface of the insect) and part of the pollen fulfils a polliniferous function (pollen from the lW, which adheres to the dorsal surface). Species that use a pump mechanism have very low Rv values (Rv=0.08−0.26); species with valvular or nonspecialized explosive mechanisms have Rv values between 0.24 and 0.58; those with a specialized mechanism of pollen presentation have high Rv values (0.6−0.76). In contrast to expectations, the highest P/O ratios appear in the specialized explosive system, which allows a single visit from the insect.
International Journal of Plant Sciences | 2014
Manuel de la Estrella; Jan J. Wieringa; Barbara A. Mackinder; Xander M. van der Burgt; Juan Antonio Devesa; Anne Bruneau
Premise of research. Gilbertiodendron is a genus endemic to Africa with ∼30 species made up of trees of primary dry-land, riverine, and gallery forests. Recently, the west and central African monotypic genus Pellegriniodendron was merged into Gilbertiodendron. Gilbertiodendron is one of 17 genera that form the exclusively African Berlinia clade, and this study presents the findings of a phylogenetic analysis designed to evaluate the generic limits of Gilbertiodendron and its relationships within the Berlinia clade. Methodology. To test the monophyly of Gilbertiodendron and its relationships with other genera, we analyzed nucleotide sequence data from the nuclear ribosomal internal transcribed spacer and the plastid trnL intron and trnL-F intergenic spacer, using parsimony and Bayesian analyses. Pivotal results. Gilbertiodendron is recovered as monophyletic, including all the samples previously recognized as Pellegriniodendron diphyllum. Conclusions. The placement of Pellegriniodendron in synonymy with Gilbertiodendron is supported by our results. Our analyses suggest that G. diphyllum is the same taxon on both sides of the Dahomey Gap. The G. ogoouense complex is a monophyletic group of species that needs a new taxonomic framework and within which several new species will be described. The phylogenetic framework presented here and the ongoing taxonomic revision should provide the baseline data required for adequate assessment of this group of tree species, of which only eight have been assessed under the International Union for Conservation of Nature’s Red List criteria.
PhytoKeys | 2017
Gloria Martínez-Sagarra; Pilar Abad; Juan Antonio Devesa
Abstract A study of the leaf anatomy in the species of the genus Festuca present in the Iberian Peninsula was made. A total of 68 taxa were included and 15 characters were measured in leaf cross-section. The major anatomical features of each taxonomic group were characterized, and some variability was observed in the taxa. The anatomical patterns observed were compared and discussed with the relationships suggested by the molecular analyses. The leaf outline, the presence or absence of complete girders, and the development degree of the bulliform cells were the main characters to differentiate among fescue species of the fine-leaved clade and those of the broad-leaved clade. The most useful character to segregate species groups within the different taxonomic sections was the arrangement of the sclerenchyma, and a remarkable variability of this character was found in the species of Festuca section Festuca, especially in those located in other lineages according to molecular markers. Most of the anatomical patterns were not exclusive of the sections or lineages, and only some taxa could be anatomically differentiated at species level based on a set of non-taxative characters. The discordant pattern observed in F. henriquesii, a species traditionally included in Festuca sect. Festuca that shared anatomical features with the species of “F. rubra complex”, suggests its possible inclusion in the sect. Aulaxyper pending further taxonomic and phylogenetic analyses.
Taxon | 2004
Juan Antonio Devesa; Ana Ortega-Olivencia; Josefa López
Hispano-Lusitanian plants traditionally identified as Scabiosa semipapposa Salzm. ex DC. are recognized with a new name, Scabiosa galianoi Devesa, Ortega-Olivencia & J. LOpez, after it was found that they differ clearlyfrom the Moroccan plants on which De Candolles description was based.
Acta Botanica Gallica | 1998
Trinidad Ruiz Téllez; Juan Antonio Devesa; Josefa López
Summary The utility of leaf anatomy in the taxonomy of the genus Deschampsia is discussed. To this end, the inter-and intra-populational variability of this character is analyzed in the taxa of the genus which are represented in the Iberian Peninsula (Deschampsia cespitosa (L.) Beauv. s.l., D. setacea (Huds.) Hack, and D. flexuosa (L.) Trin.), as well as in Holcus grandiflorus Boiss. and H. caespitosus Boiss., two Spanish endemic species which some authors include in Deschampsia. A critical analysis of their observed anatomical plasticity is given, evidencing the great intra-individual variability when wild plants are grown under experimental conditions.
PhytoKeys | 2018
Ana Ortega-Olivencia; Juan Antonio Devesa
Abstract Based on our study of 4,845 herbarium sheets of the genus Poa from the area covered by Flora iberica, namely, the Iberian Peninsula and the Balearic Islands, we recognise 24 taxa (17 species, 1 subspecies and 8 varieties), mostly perennials. Most of these taxa have wide global and/or European distributions, while two (P. legionensis and P. minor subsp. nevadensis) are Spanish endemics and two have restricted distributions (P. ligulata, Iberia–North Africa; P. flaccidula, Iberia–North Africa and the Balearic Islands, extending to Provence, France). We have studied the original publications of more than 225 names considered as synonyms, with those more historically cited in Flora iberica taken into account in this paper; a total of 26 are new synonyms. The following names are typified: P. alpina var. involucrata Lange, P. annua var. lanuginosa Sennen, P. minor subsp. nevadensis Nannf., P. paui Font Quer, P. sulcata Lag. and P. trivialis var. flaccida Willk. ex J.J. Rodr. We include P. compressa L. in the flora of Portugal for the first time and present detailed illustrations of three very interesting taxa (P. legionensis, P. minor subsp. nevadensis and P. ligulata). In addition to a general species key, we provide the following information for each taxon: synonyms, types, typification, the most relevant iconography, regional flowering time, regional and general distribution and, as supplementary material, the number of sheets examined and a list of selected materials.
Oikos | 2005
Ana Ortega-Olivencia; Tomás Rodríguez-Riaño; Francisco J. Valtueña; Josefa López; Juan Antonio Devesa
Botany | 1999
Tomás Rodríguez-Riaño; Ana Ortega-Olivencia; Juan Antonio Devesa
Phyton | 1999
Josefa López; Juan Antonio Devesa; Trinidad Ruiz; Ana Ortega-Olivencia
Annals of Botany | 1999
Tomás Rodríguez-Riaño; Ana Ortega-Olivencia; Juan Antonio Devesa