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Kozlowski G. and Eggenberg S. 2005. Distribution of the least water-lily (Nuphar pumila) and the hybrid N. x intermedia in Switzerland. Bot. Helv. 115: 125-136.The least water-lily (N. pumila (TIMM.) DC) is very rare and endangered in Switzerland and Central Europe. To provide a basis for its conservation, we present a distribution map with all natural, re-introduced and extinct populations in Switzerland. Only four natural populations of N. pumila still exist in Switzerland: Lac de Lussy and Lac des Joncs (FR), Gräppelensee (SG), and Kämmoosteich (ZH). These populations and their sites (lakes) are described, and the co-occurring plant species are listed. Results suggest that the populations from Kämmoosteich and Lac de Lussy are affected by hybridisation and competition with N. lutea. In these two lakes, the hybrid N. x intermedia was very abundant. The presence of N. lutea and N. intermedia in Kämmoosteich and Lac de Lussy should be regarded as one of the most serious threats of pure N. pumila populations. To facilitate further investigation and conservation field work, a detailed morphological description of the two taxons is presented and illustrated by original drawings. To escape extinction in Switzerland, N. pumila needs further appropriate action plans for all natural and newly re-introduced sites as well as an improved knowledge of its genetic structure and habitat preferences.Key words: Conservation biology, distribution map, endangered plant species, hybridisation, Nupharetum pumili, Nympheaceae. EinleitungWährend des letzten Jahrhunderts hat sich unsere Landschaft in vielen Regionen stark verändert; damit wurde auch die Pflanzenwelt erheblich beeinträchtigt. Besonders bedroht sind Arten feuchter Standorte, deren natürliche Lebensgrundlagen durch Entwässerung, Torfausgrabungen und Intensivierung der Landwirtschaft weitgehend 1 Published in "Botanica Helvetica 115(2): 125 -136, 2005" which should be cited to refer to this work.

Despite increasing awareness of global biodiversity loss, we lack quantitative data on local extinctions for many species. This is especially true for rare species, which are typically assessed on the basis of expert judgment rather than data. Revisiting previously assessed populations enables estimation of local extinction rates and the identification of species characteristics and habitats with high local extinction risk. Between 2010 and 2016, in a nationwide revisitation study, 420 volunteer botanists revisited 8,024 populations of the 713 rarest and most threatened plant species in Switzerland recorded between 1960 and 2001. Of the revisited 8,024 populations, 27% had gone locally extinct. Among critically endangered species, the local extinctions increased to 40%. Species from ruderal and freshwater habitat types showed the highest proportion of local extinctions. Our results provide compelling evidence for rapid and widespread local extinctions and suggest that current conservation measures are insufficient. Local extinctions precede and provide early warnings for global extinctions. The ongoing loss of populations suggests that we will lose species diversity unless we scale up species-targeted conservation and restoration measures, especially in anthropogenic landscapes.

Vittoz P., Selldorf P., Eggenberg S. and Maire S. 2005. Festuca paniculata meadows in Ticino (Switzerland) and their Alpine environment. Bot. Helv. 115: 33-48.

Eggenberg S. and Landolt E. 2006. For which plant species does Switzerland have an international responsibility? Bot. Helv. 116: 119 -133.Priorities in plant species conservation are often based on national Red Lists. In an international context, however, the Red List status (threat) of a species within a limited territory may be misleading because the local disappearance of a species may or may not have serious implications for its global persistence. A second important aspect to consider in species conservation is therefore the responsibility of a country for the species, i.e. the importance of the conservation of local populations for the persistence of the species worldwide. In this contribution, we assess the responsibility of Switzerland for its vascular flora using three biogeographical criteria: (1) the Swiss portion of the species range (high responsibility for species with a large fraction of the range in Switzerland), (2) the degree of endemism (high responsibility for species with a small total range) and (3) the degree of isolation (high responsibility for isolated outposts, which may contain a large part of a species genetic variation). The three criteria were derived for each species from global and European distribution maps, and were then combined to an overall index of responsibility. On this basis, 397 taxa for which Switzerland has an intermediate to high international responsibility were identified. These are almost 15% of the whole vascular flora of Switzerland. Of the 397 taxa, 75% are endemic species of the Alps, and 48% are threatened taxa within Switzerland. The Responsibility List can be used together with the Red List to set priorities in plant conservation or to identify areas of particular floristic value.