This paper provides a comparison of the vascular exotic flora of Sardinia and that of the Balearic Islands, both territories belonging to the Western Mediterranean biogeographic subregion. The study has recorded 531 exotic taxa in Sardinia (18.8% of the total flora) while 360 (19%) in the Balearic Islands; 10 are new to Sardinia (3 of which for Italy) and 29 to the Balearic Islands. The alien flora of Sardinia is included in 99 families; Fabaceae is the richest (49 taxa), followed by Poaceae (33) and Asteraceae (31) while in the Balearic Islands in 90 families, with a predominance of Fabaceae (32), Asteraceae (31) and Poaceae (27). The comparison of the biological spectra reveals that in Sardinia phanerophytes are the most represented in Sardinia and therophytes in the Balearic Islands. A detailed analysis shows that most of the exotic taxa (246) are shared by both territories with a clear dominance of neophytes rather than archaeophytes. A study of the geographical origin shows supremacy of the American element over the Mediterranean. The majority of introduced exotic taxa are a result of intentional human introductions (76% SA, 77% BL), mainly for ornamental use (43% SA, 45% BL). The most occupied habitats are the semi-natural, agricultural and synanthropic for both territories, but attending to invasive plants, coastal habitats in Sardinia and wetlands in the Balearic Islands are the most sensitive. A part of the work deals with the causes of fragility and low resilience of the different habitats.Keywords: alien species, biogeography, conservation, invasions, Mediterranean. Se presenta un estudio comparativo de la flora vascular exótica de Cerdeña y de las Baleares, dos sistemas insulares pertenecientes a la subregión biogeográfica Mediterránea Occidental. En Cerdeña se han contabilizado 531 táxones exóticos (18,8% del total de su flora), mientras que en las Baleares 360 (19%), siendo 10 citas nuevas para Cerdeña (3 de las cuales para Italia) y 29 para Baleares. La flora exótica de Cerdeña está incluida en 99 familias, y Fabaceae es la más rica (49 táxones), seguida por Poaceae (33) y Asteraceae (31), frente a 90 familias para las Baleares, con predominio de Fabaceae (32), Asteraceae (31) y Poaceae (27). Se han encontrado diferencias respecto a los tipos biológicos, con un predominio de los fanerófitos en Cerdeña y de los terófitos en las Baleares. Un análisis detallado muestra que buena parte de estos táxones (246) son compartidos por ambos territorios, así como una dominancia de los neófitos frente a los arqueófitos. Respecto al origen geográfico, ambos territorios presentan una preeminencia del elemento americano sobre el mediterráneo. En referencia a las vías de introducción, la mayor parte de los táxones ha sido introducida por parte del hombre de forma intencionada (76% SA, 77% BL) en particular para uso ornamental (43% SA, 45% BL). Los hábitats más afectados son los seminaturales, agrícolas y sinantrópicos en ambos territorios, aunque atendiendo a la flora invasora, son los litorales los más sensibles ...

This article provides a comparison of the invasive vascular flora of Sardinia\ud and that of the Balearic Islands. The study has recorded 53 invasive taxa in Sardinia (12%\ud of the alien flora) while 48 (14%) in the Balearic Islands, 19 of them common for both\ud territories. The invasive flora of Sardinia is included in 18 families; Asteraceae is the\ud richest in taxa, followed by Amaranthaceae, while in the Balearic Islands in 19 families,\ud with a predominance of Poaceae and Asteraceae. The comparison of the biological\ud spectrum reveals that in Sardinia therophytes and phanerophytes are the most represented,\ud as well as therophytes and hemicryptophytes are in the Balearic Islands. Neophytes are\ud clearly dominant comparing to archaeophytes. A study of the geographical origin shows\ud supremacy of the American element. The majority of invasive taxa is a result of intentional\ud human introductions, mainly for ornamental use. The most occupied habitats in both\ud territories are the semi-natural, agricultural and synanthropic for both territories, followed by natural habitats as coastal ones in Sardinia and wetlands in the Balearic Islands. An\ud important part of the work deals with the environmental, economic and human-health\ud impact

Fraga i Arguimbau, P. 2008. Vascular flora associated to Mediterranean temporary ponds on the island of Minorca. Anales Jard. Bot. Madrid 65(2): 393-414.Mediterranean temporary ponds are a habitat with a high interest for conservation due to their particular characteristics and especially to their biodiversity. Vascular flora is a feature that stands out for its richness and diversity. Minorca has a high representation of this habitat. A complete inventory of vascular plants related to this habitat on the island is presented here for the first time. 360 taxa have been recorded in the pond areas. Most of them are usually found outside the water influence, and just 35 have been found to be exclusive to the inundation area. The quantitative analysis of additional information like abundance within the island, chorology and life forms, compared with that of all the flora on the island, reveals some particular traits for the flora of this habitat, and especially for the plants of the inundated area. Los humedales temporales mediterráneos están catalogados como hábitats prioritarios de conservación en la Unión Europea por sus características ambientales y por su elevada biodiversidad, en la que destaca su interesante flora vascular. En la isla de Menorca se encuentra una notable representación de este tipo de ecosistema acuático. En este trabajo se ofrece, por primera vez, un inventario completo de la flora asociada a estos ambientes. Se han identificado 360 táxones, de los cuales solamente 35 están relacionados con las zonas inundadas. El análisis realizado para cada taxon -abundancia en la isla, corología y biotipos-, comparado con el realizado para el conjunto de la flora de la isla, pone de manifiesto algunos aspectos peculiares de la mencionada flora de estos hábitats, especialmente para los táxones exclusivos de la zona inundada.

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This paper describes a new species, Orobanche iammonensis A.Pujadas & P.Fraga [section Orobanche L. grex Minores (Beck) Teryokhin] from the west coast of Minorca, Balearic Islands. The new species inhabits coastal rocky slopes and is parasitic on Anthemis maritima L. It is a small yellow plant characterized by a dense inflorescence with erecto-patent to subpatent pale yellow flowers and by eglandular and glandular hairs at the base of the corolla. The morphological features suggest a relationship of this new species to grex Minores, especially to O. litorea Guss., a plant distributed widely in the central Mediterranean. A complete description is given in this paper, including the diagnostic characteristics which allow the differentiation from O. litorea and other related taxa. Data on ecological and conservation status are also presented.