Circumscription and phylogeny of the fern family Tectariaceae based on plastid and nuclear markers, with the description of two new genera: Draconopteris and Malaifilix (Tectariaceae)

The circumscription and the phylogeny of the fern family Tectariaceae have been controversial. Previous molecular studies have supported the monophyly of this family, with 4-5 genera. However, these studies were exclusively based on plastid markers and relatively small sampling, especially of the non-Tectaria genera. In the present study, DNA sequences of eight plastid and one nuclear markers of 25 accessions representing 19 species of Tectaria and 58 accessions representing ca. 90% of the non-Tectaria species in the family (including Arthropteris) were used to infer a phylogeny using maximum likelihood (ML), Bayesian inference, and maximum parsimony. Our major results include: (1) Tectaria as currently circumscribed is not monophyletic and can be divided into three genera: Tectaria s.str., Draconopteris (gen. nov.) from Central to South America, and Malaifilix (gen. nov.) from Malesia; (2) Draconopteris and Malaifilix, the two new genera, together with Pteridrys, form a strongly supported Glade; (3) in our ML analyses, the Glade containing Draconopteris, Malaifilix, and Pteridrys (the DMP Glade) is resolved as sister to the rest of Tectariaceae and Arthropteris is sister to Tectaria+(Hypoderris + Triplophyllum), suggesting that Arthropteris should be treated as a member of Tectariaceae, and thus Tectariaceae contains seven genera: Arthropteris, Draconopteris, Hypoderris, Malaifilix, Pteridrys, Tectaria, and Triplophyllum; (4) with the well-supported relationships among the members of Tectariaceae, anastomosing venation in the family is inferred to have evolved independently at least three times; (5) Nephrolepis is strongly supported as sister to a Glade containing Cyclopeltis, Dracoglossum, and Lomariopsis, and thus we advocate that Lomariopsidaceae include these four genera (plus the unsampled Thysanosoria); and (6) intercontinental dispersal appears to have played an important role in shaping the extant distribution of Tectariaceae.