Nouvelles citations pour la flore de l'archipel des Berlengas (Estremadura, Portugal)

Novas citacóes para a flora do arquipélago das Berlengas (Estremadura, Portugal)Mots cié. Chorologie, iles, Reserva Natural das Berlengas, Portugal.Palavras chave. Corologia, ilhas, Reserva Natural das Berlengas, Portugal

Rumex palustris Sm. (Polygonaceae), nueva especie para la flora de Portugal

Rumex palustris Sm. es una planta anual o bienal, de distribución eurosiberiana aunque introducida en América desde 1877 (Dawson, 1979). Se extiende hacia el norte, hasta Dinamarca y este, hasta Turquía. Se distingue perfectamente de sus congéneres por sus hojas basales, cuneadas en la base y mucho más largas que anchas. A pesar de que la distribución de esta especie en la Península Ibérica presenta varia lagunas, durante los trabajos de monitorización de la fl ora afectada por el embalse de Alqueva se ha recolectado este taxón, hasta el momento desconocido para la flora portuguesa

Natural hybridisation between two coastal endemic species of Armeria (Plumbaginaceae) from Portugal. 2. Ecological investigations on a hybrid zone

SCOPUS: er.jinfo:eu-repo/semantics/publishe

Natural hybridisation between two coastal endemic species of Armeria (Plumbaginaceae) from Portugal. 1. Populational in situ investigations

Armeria pseudoarmeria and A. welwitschii, two endemics from the atlantic coast in the centre of Portugal, are shown to be quite distinct by multivariate morphological analyses. In their contact zone around Cabo da Roca, hybrid populations comprising parental morphs and intermediates occur in abandoned agricultural fields. A proportion of intermediates is partially male sterile while others are fully fertile, indicating a rapid recovering of total fertility by some hybrids. The reproductive fitness traits we investigated do not suggest that the hybrids are inferior to the parents but rather that they could be adapted to the hybrid zone environment. Although being a very distinct species among the Iberian Armeria, A. pseudoarmeria is able to cross successfully with A. welwitschii in natural conditions. © Springer-Verlag 2005.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Différenciation et hybridation chez trois espèces endémiques d'Armeria (Plumbaginaceae) du littoral portugais

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

Natural hybridisation between two coastal endemic species of Armeria (Plumbaginaceae) from Portugal. 2. Ecological investigations on a hybrid zone

A clinal range of morphological variation between two coastal endemic species of the Genus Armeria in Portugal (A. pseudoarmeria and A. welwitschii) was investigated to test the hypothesis of hybrid advantage in contact zones between species. The putative F1 hybrids morphotypes could be submitted to endogenous selection as most of them show deficiencies in pollen fertility and seed setting in comparison with the parental species. Reciprocal transplant experiments in three sectors along the cline revealed that the intermediate F1 morphotypes are less productive in biomass than the parents even in their sector of origin. These data do not show evidence for the Hybrid Bound Superiority Model. Rather they are in favour of the Tension Zone Model where a dynamic balance is obtained between the continuous production of hybrids and the selection against them. Nevertheless the Tension Zone Model postulates similar fitness for the parents along the cline, which is not the case as the parents are clearly differentiated for nutrient uptake. Soil and plant leaf elemental analysis revealed that, in transplantation, some of the hybrids correspond to a geochemical specialisation diverging from that of the parents suggesting a local adaptation. Owing the high frequency and the healthy developmental aspect of the intermediate morphs in central and northern sector selection must be weak against hybrids. It is concluded that in natural situations the two models could not be strictly exclusive. © 2008 Springer-Verlag.SCOPUS: ar.jinfo:eu-repo/semantics/publishe