Het roodwier Thorea ramosissima Bory (Rhodophyta) nieuw voor de Nederlandse flora

Specimens of the freshwater red alga Thorea ramosissima were recently found at two nearby localities in the river Meuse in the Netherlands. The plants were epilithically growing 10-30 cm below the water surface. A description of the thallus of this alga is given, completed with some taxonomic remarks. It is concluded that Thorea ramosissima has a Central European to Mediterranean distribution on the European continent.