The occurrence of communities with species of Ranunculus subgenus Batrachium in central Europe — preliminary remarks

Abstract

A short outline of the history of the description of Batrachium communities with special regard to taxonomic reliability is given. Own investigations concern firstly the distribution of Batrachium taxa in Lower Saxony (north Germany). Some taxonomical problems are discussed. The Batrachium species are classified with regard to growth form into two structural groups and the different distribution of these groups within a drainage area is mentioned. The problems arising from the classification of the communities dominated by small Batrachium species with floating leaves are discussed in more detail using a distribution map of characteristic and associated species. With regard to a wider geographical area (central Europe), 3 types of Batrachium communities are distinguished and characterized floristically. The great complexity of the problem is pointed out. Finally, the phytosociological behaviour of the 7 most frequent Batrachium species is discussed with special reference to the different types of waters that are colonized.

Nomenclature follows Cook (1966)

We thank Dr. N. T. H. Holmes (Huntingdon. U. K.) and Prof. Dr.C.D. K. Cook (1966).(Zürich , Switzerland) for their help with taxonomical problems of Ranunculus subgenus of the Niedersächsisches Landesverwaltungsamt and the Landesamt für Natur- und Umweltschutz Schleswig-Holstein.