The far from miserable flora of the muddy banks downstream the “Misère” forebay of the Upper-Sûre lake in Luxembourg.

Abstract

A recent survey of the muddy banks of the Upper-Sûre reservoir in Luxembourg led to the discovery of a considerable number of rare vascular plants and bryophytes as well as several insufficiently documented habitats for Luxembourg. Bidens radiata is newly listed for Luxembourg – locally occurring on gravel banks –, Leersia oryzoides has rarely been recorded in Luxembourg, while Panicum barbipulvinatum has only been observed once in 2005. Riccia cavernosa, Riccia huebeneriana and Physcomitrium sphaericum are among the bryological peculiarities. After the water receded, we observed an explosive spread of the uncommon alga Botrydium granulatum, covering large areas with its green globules. The muddy banks are a habitat for specific plant communities with many rare and protected species. Unfortunately, national legislation omits to protect this FFH Annex I habitat “3270 Rivers with muddy banks with Chenopodion rubri p.p. and Bidention p.p. vegetation”.