Fig. 1.—

Hypotheses on the backbone relationship of eupolypod II ferns with special reference to the positions of Rhachidosoraceae and Athyriaceae. (a) Topology resolving Rhachidosoraceae as sister to the Thelypteridaceae-Blechnaceae clade in Kuo et al. (2011); (b) topology resolving Rhachidosoraceae as sister to the Aspleniaceae-Diplaziopsidaceae clade in Rothfels et al. (2012b); (c) topology showing Athyriaceae as nonmonophyletic in Kuo et al. (2011), Rothfels et al. (2012b) and Wei et al. (2013); and (d) topology showing unresolved relationships within eupolypod II ferns in Rothfels et al. (2015) based on 25 low-copy nuclear genes.