A morpho-molecular classification of the Anthocerotophyta (hornworts)
Frey, Wolfgang; Stech, Michael
Recent molecular analyses and a re-evaluation of morphological and anatomical characters provided new insights into relationships among hornworts (Anthocerotophyta). Considering these results, a new suprageneric classification of hornworts is formally proposed. The monospecific genus Leiosporoceros (Leiosporocerotales) is separated into its own class Leiosporocerotopsida class. nov., based on its unique combination of molecular and non-molecular characters. Within the Anthocerotopsida, three orders are distinguished, Anthocerotales (comprising Anthocerotaceae and Foliocerotaceae), Phaeocerotales (Phaeocerotaceae and Notothyladaceae) and Dendrocerotales (Dendrocerotaceae). The latter comprises genera Dendroceros, Megaceros and Nothoceros, as well as some species of Phaeoceros according to the molecular analyses, which are morphologically intermediate between Megaceros and Phaeoceros. Taxonomic consequences at the generic level within hornworts are advisable only after further molecular investigations including additional markers and a broader taxon sampling.