This work is the culmination of well over 30 years’ personal study of Britain’s hepatic flora in the field which has enabled the author to take into account the full range of variation of each taxon. The Introduction comprises sections on Collection and preservation, Examination of material, Measurements, Habitats and distribution, Conservation, Function and use of keys, Explanation of text, Abbreviations and symbols used in the text, Explanation of figures, Abbreviations and symbols used in the figures (also provided on plastic bookmark). The systematic section begins with a Conspectus of classification followed by the accounts of genera with keys, and of species, each copiously illustrated in meticulous detail by the author – a magnum opus in its own right. The work concludes with Glossary, Vice-counties in the British Isles and map, Bibliography and Index. Unrevised Brill edition.