Afro-American Hepatics Revisited

Abstract

AbstractIn 1983, Gradstein, Pócs and Váňa discussed the disjunct Afro-American ranges of 41 liverwort species and 8 genera. Since the appearance of this paper much progress has been made in the study of tropical liverworts and knowledge of the neotropical and African floras has improved considerably. The new investigations have raised the number of Afro-American hepatics to 74 species, 13 genera and one family (Oxymitraceae). Afro-American species constitute about 5% of the neotropical liverwort flora and 8% of the flora of Africa. The percentages of species shared by the two continents are doubled when pantropical species are added. Five Afro-American species are newly recognized in this paper: Calypogeia peruviana Nees & Mont. (= C. afrocaerulea E. W. Jones, syn. nov.), Ceratolejeunea coarina (Gottsche) Steph. (= C. diversicornua Steph., syn. nov.), C. ornithocephala Herzog (= C. kilimanjarica Pócs & Ast, syn. nov.), Odontoschisma variabile (Lindenb. & Gottsche) Trevis. (= O. africanum Steph., syn. nov.) and Syzygiella manca (Mont.) Steph. [= S. geminifolia (Mitt.) Steph., syn. nov.]. Spore dispersal experiments and molecular-phylogenetic studies have shown that the intercontinental ranges of liverwort species, and of the majority of genera, should have resulted from long-distance dispersal events, not from vicariance.