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Santolina is a clear example of a genus lying in an alpha‐taxonomic status, with species accepted only based on qualitative morphological descriptions. In particular, taxonomic issues still need to be resolved for Santolina populations from southern France and north‐eastern Spain, and so, we carried out an integrative taxonomic study involving morphometrics, cypsela morphometrics, niche overlap, and phylogenetic analysis based on six plastid markers (trnH‐psbA, trnL‐trnF, trnQ‐rps16, rps15‐ycf1, psbM‐trnD, and trnS‐trnG). Our results revealed that the current taxonomic circumscription is not adequate. In particular, the Santolina populations at the foothills of eastern Pyrenees, previously included in the variability of Santolina benthamiana, have to be considered as a distinct species, namely, Santolina intricata. In addition, despite their high phylogenetic relatedness, S. benthamiana s.str. and Santolina ericoides can still be considered as distinct species due to clear morphological and ecological differentiation. Finally, we demonstrated that three different subspecies can be recognized in Santolina decumbens, a species endemic to Provence. For one of these subspecies, due to its extremely restricted distribution range, conservation issues are pointed out. [ABSTRACT FROM AUTHOR]

When exotic species spread over novel environments, their phenotype will depend on a combination of different processes, including phenotypic plasticity (PP), local adaptation (LA), environmental maternal effects (EME) and genetic drift (GD). Few attempts have been made to simultaneously address the importance of those processes in plant invasion. The present study uses the well-documented invasion history of Senecio inaequidens (Asteraceae) in southern France, where it was introduced at a single wool-processing site. It gradually invaded the Mediterranean coast and the Pyrenean Mountains, which have noticeably different climates. We used seeds from Pyrenean and Mediterranean populations, as well as populations from the first introduction area, to explore the phenotypic variation related to climatic variation. A reciprocal sowing experiment was performed with gardens under Mediterranean and Pyrenean climates. We analyzed climatic phenotypic variation in germination, growth, reproduction, leaf physiology and survival. Genetic structure in the studied invasion area was characterized using AFLP. We found consistent genetic differentiation in growth traits but no home-site advantage, so weak support for LA to climate. In contrast, genetic differentiation showed a relationship with colonization history. PP in response to climate was observed for most traits, and it played an important role in leaf trait variation. EME mediated by seed mass influenced all but leaf traits in a Pyrenean climate. Heavier, earlier-germinating seeds produced larger individuals that produced more flower heads throughout the growing season. However, in the Mediterranean garden, seed mass only influenced the germination rate. The results show that phenotypic variation in response to climate depends on various ecological and evolutionary processes associated with geographical zone and life history traits. Seeing the relative importance of EME and GD, we argue that a "local adaptation vs. phenotypic plasticity" approach is therefore not sufficient to fully understand what shapes phenotypic variation and genetic architecture of invasive populations. [ABSTRACT FROM AUTHOR]

The antimicrobial activity of 28 essential oil samples isolated from local plants or plants cultivated in Corsica was evaluated against a large panel of human pathogenic bacteria, including Campylobacter jejuni which appeared as a good model for this purpose. The chemical composition of the 18 oils selected for their efficiency was determined by GC and GC/MS. Among them, the oils of Cistus ladaniferus, Crithmum maritimum, Daucus carota, Juniperus communis, Mentha aquatica and Santolina corsica showed compositions without components known as active, suggesting the presence of compounds not previously described as antibacterial agents. [ABSTRACT FROM AUTHOR]

Aim The problems in public health and field management in France caused by Ambrosia artemisiifolia L. require a better knowledge of the introduction and naturalization of this species in both the past and present. Location France. Methods The pattern of spread of A. artemisiifolia was investigated through the study of herbarium specimens. More than 1200 specimens were found in 58 herbaria and virtual herbaria in France and in bordering countries. The spread was analysed by mapping the localities for each 30-year period since 1863. Specific indications as ‘new plant’ were used to determine the timing of the introduction of the species into a new area. Results It seems that the spread of A. artemisiifolia is not linked to its presence in botanical gardens. The study of specimen labels indicates that this species has been introduced in France in seed crops at various independent geographical points and at various times since its introduction in natural habitats. Commercial trade and American troops have contributed to its spread. Main conclusions The spread of the species in area and in time over France showed no clear front: new localities separated by large distances were colonized simultaneously. Cumulative numbers of localities show a continuous increase during the twentieth century. Herbarium specimens can be used to follow the spread of A. artemisiifolia. [ABSTRACT FROM AUTHOR]