A Taxonomic Monograph of the Genus Acrolejeunea (Hepaticae) with an Arrangement of the Genera of Ptychanthoideae (Studies on Lejeuneaceae subfam. Ptychanthoideae III)

The present study was initiated a few years ago by Dr. R. Grolle (Jena) who discovered that Acrolejeunea (Spruce) Schiffn. was probably the correct name for a tropical liverwort genus to which in this century the name Ptychocoleus Trev. was applied. Since replacing the name Ptychocoleus by Acrolejeunea would necessitate a considerable number of nomenclatural changes, I was asked to reexamine the taxonomy of the group. I soon found that Ptychocoleus as traditionally understood is heterogeneous and consists of two well-defined genera: Acrolejeunea (Spruce) Schiffn. and Schiffneriolejeunea Verd. (Gradstein 1974a). In order to determine their taxonomic affinities, I decided to review the generic subdivision of the subfamily Ptychanthoideae (Lejeuneaceae) to which they belong. The present work comprises the taxonomic monograph of Acrolejeunea and the review of the subfamily. The monograph of Schiffneriolejeunea will be published separately.