Small pondweed communities

Formations of smaller pondweeds, in particular, [Potamogeton crispus], [Potamogeton pusillus], [Potamogeton berchtoldii], [Potamogeton trichoides], [Potamogeton acutifolius], [Potamogeton pectinatus], [Groenlandia densa], horned pondweeds ([Zannichellia palustris] s.l.), naiads ([Najas] spp.), tapegrass ([Vallisneria spiralis]), water crowfoots ([Ranunculus spp]) that colonize shallower, more sheltered Palaearctic waters. Eurasian formations dominated by usually free-floating hornworts of genus [Ceratophyllum], in particular by [Ceratophyllum demersum], are included because of closer ecological and physiognomic similarity with communities of this unit than with those of unit 22.41 (Corine).