Freshwater Flora of Central Europe, Vol 13: Chlorophyta: Ulvophyceae (Süßwasserflora von Mitteleuropa, Bd. 13: Chlorophyta: Ulvophyceae)

This volume of the “Süßwasserflora von Mitteleuropa” (Freshwater Flora of Central Europe) covers the freshwater, aerophytic, and terrestrial species of Ulvophyceae. The class includes about 1700 species, and is one of the main classes of green algae (Chlorophyta). Although most of the species diversity of Ulvophyceae is found in the marine environment, a substantial number of species also occurs in brackish, freshwater, and aero-terrestrial habitats. These species are found in nine orders: Ulvales and Ulotrichales, which contain most freshwater species, the Trentepohliales which is exclusively aero-terrestrial, the smaller orders Chlorocystidales, Oltmannsiellopsidales, Scotinosphaerales, and Ignatiales, and the large but mainly marine orders Cladophorales and Bryopsidales. One other order, Dasycladales, only includes marine species and is thus not included in the present volume. Freshwater ulvophycean algae display a wide variety of thallus morphologies, ranging from microscopic unicellular organisms to larger, filamentous or parenchymatic algae. Species are also found in a wide diversity of habitats, generally attached, or sometimes free-floating. Several marine species occur over a broad salinity range, and are found in brackish to freshwater and semi-terrestrial habitats. Other species are restricted to freshwater or aero-terrestrial habitats. Several species are found in highly specialized habitats such as epizoic on freshwater snails or on carapaces of freshwater turtles, epiphytic on aquatic lichens or as lichen phycobionts, or endophytic in filamentous algae or mesophyll of vascular plants. This volume serves as a reference work for identifying these ulvophyte green algae by providing keys, detailed descriptions, and illustrations of the more than 100 European species. As in other volumes of this series, this treatment is not restricted to European taxa, and includes descriptions and illustrations of more than other 100 taxa found on other continents. The present study incorporates the latest findings in molecular phylogeny, ultrastructure and morphology for the classification, delimitation and identification of the species. In addition, it significantly revises the taxonomy of ulvophytes, in particular the orders Ulvales and Ulotrichales, based on new molecular phylogenetic data, combined with morphological data. We propose to resurrect one order and family (Chlorocystidales and Chlorocystidaceae), and describe five new families (Binucleariaceae, Planophilaceae, Hazeniaceae, Sarcinofilaceae, and Tupiellaceae). In addition, we formally describe the order Ignatiales and family Ignatiaceae based on published molecular and ultrastructural data. This book is one of the first comprehensive treatments of species diversity of nonmarine Ulvophyceae, and we hope that it will be a useful tool in ulvophyte research worldwide.