Découverte d’une nouvelle localité de Berle à larges feuilles Sium latifolium L., 1753 dans la Réserve naturelle nationale de la forêt d’Offendorf (France, Grand Est, Bas-Rhin) et état des menaces en Alsace

Abstract  ̶  A new location of Greater water parsnip Sium latifolium L., 1753 has been discovered in 2022 in the Offendorf forest National nature reserve (France, Grand Est, Bas-Rhin), an Apiaceae of paludean habitats in strong decline. The location is a pond created in 2005 as part of the restoration of a small arm of the Rossmoerder, an old arm of the Rhine river. It complements the other three known localities of the species in Alsace, all of which are endangered in the short terme with the exception of the one in the Sauer delta (Grand Est, Bas-Rhin, Munchhausen). This discovery suggests that other localities could still exist in the Rhine floodplain north of Strasbourg and also proves that restoration can favor the species come back.