This guide book to the aquatic bryophytes in Finland is the first part of a series comprising a complete bryophyte ﬂora of Finland. The mosses and hepatics dealt with grow more or less continuously in water: in brackish water, lakes, springs, brooks or streams, either attached to the substrate (Fontinalis antipyretica), or ﬂoating freely (Drepanocladus tenuinervis). Descriptions are given for 57 species, and 48 species appear in figures.
The Introduction discusses the structure and the alternation of generations, plus the ecology, habitats and distributions of the aquatic bryophytes. This introduction is followed by a vocabulary of terms and a key to genera and to some of the species. The flora part consists of keys to the species and short descriptions of the genera and of their aquatic species, with special attention paid to the habitat ecology of these bryophytes. The taxonomy and characteristic features of the terrestrial relatives of aquatic bryophytes are also compared and discussed. A selection of recent literature citations is given in connection with the descriptions.
Distribution of the species in Finland is given on small-scale maps according to the biogeographical provinces as follows:
- more or less common
- rare or less frequent