Identity:

Emergent Eleocharis parvula-dominated formations of brackish seas, sea inlets, estuaries, permanent pools of mud or sand flats, and coastal lagoons. They occur in the open sea only in the inner Baltic, in particular in middle Sweden, southern Finland and Estonia; they are very rare elsewhere, noted in particular on a few points of the coasts of Norway and in closed limans of the northern Black Sea and Azov Sea coasts, probably extinct in France and Germany.