The remote tropical island of St Helena lies in the South Atlantic Ocean, 1800 km from Africa. With spectacular volcanic scenery ranging from desert to lush cloud forest, St Helena has a rich flora and fauna of global importance, comprising many unique and unusual species. This identification guide is the first full treatment of St Helena's mosses, liverworts and hornworts since 1875, and provides a fascinating insight into an under-explored group of plants, 26 of which are considered endemic.