Forty-one degrees below and sixty years in the dark: Frullania sect. Inconditum, a new section of Australasian Frullania species including F. colliculosa, sp. nov., F. hodgsoniae, nom. and stat. nov., F. aterrima, and F. hattorii (Frullaniaceae, Marchantiophyta)
Von Konrat, Matthew; Hentschel, Jörn; Heinrichs, Jochen; Braggins, John E.; Pócs, Tamás
The liverwort genus Frullania is large and complex, with many subgeneric boundaries, in particular, remaining largely unresolved for decades. However, advances are being made in unraveling these relationships. Many of the ambiguities are associated with units comprising a small number of taxa that have purportedly unusual features, and almost all of these are restricted to the Southern Hemisphere. Here we describe a new taxon, Frullania colliculosa, representing an important element in the Frullaniaceae because it is morphologically allied to a small group of species historically assigned to Frullania sect. Rostratae. There has been no critical reassessment of this section, which has a complicated and controversial taxonomic and nomenclatural history. Yet, for almost 40 years the section Rostratae has remained an invalidly published name since it was first proposed. We hereby propose the new section, Frullania sect. Inconditum, and clarify its nomenclatural relationship with sect. Rostratae. In light of recent molecular studies coupled with a reassessment of critical morphological and anatomical features, we here circumscribe F. sect. Inconditum to include F. aterrima, F. colliculosa, F. hattorii, and the type species F. hodgsoniae. The section clearly does not belong within subg. Microfrullania where members have historically been placed. Conversely, section Inconditum is nested within subg Diastaloba and depending on the realignments within that subgenus, E. A. Hodgson may indeed have been closer to a natural alignment nearly 60 years ago. A detailed comparison of the four Australasian species is provided, including descriptions, illustrations, tables and key. A new name, Frullania hodgsoniae, is proposed for the entity F. aterrima var. lepida and lectotypification for F. aterrima is also provided.