New data on distribution, ecology and cytology of the Azorean endemic Asplenium azoricum are presented. Hybrids involving this species are recorded for the first time. The extremely rare, natural hybrid A. azoricum × A. scolopendrium is described as A. ×santamariae. It has been found at a single location on Santa Maria Island and is presumed to be triploid. A more frequent natural hybrid A. azoricum × A. onopteris, found at seven locations on the same island, is also new to science and is described here as A. ×diasii. It is confirmed cytologically as triploid with two genomes from A. azoricum and one from A. onopteris. Asplenium ×diasii and an experimental hybrid show that A. azoricum is an allotetraploid species. The parentage and directionality of hybridization for both hybrid taxa have been established using uniparentally inherited plastid genome markers.

Thirteen genera are traditionally recognized in the subfamily Taenitidoideae, Pteridaceae. A phylogenetic study of this subfamily, based on both morphological and molecular data, was performed using an exemplar approach. Representatives of the following genera were included in the analyses: Jamesonia, Eriosorus, Pterozonium, Syngramma, Taenitis, Austrogramme, Pityrogramma, Anogramma, Actiniopteris, Onychium, and Afropteris. Specimens and DNA samples were not available for Cerosora and Nephopteris, so they were excluded. Three species were chosen as outgroups: Pteris multifida, P. quadriaurita, and Coniogramme fraxinea, all of which are restricted to the Old World. A robust phylogeny was generated based on 26 morphological characters, 578 base pairs of the plastid gene rps4 and partial data from the intergenic spacer rps4-trnS. The results reject the hypothesis of monophyly of the subfamily as presented by Tryon et al. (1990). However, the results support the monophyly of a well-supported clade consisting of Jamesonia, Eriosorus, Pterozonium, Austrogramme, Syngramma, Taenitis, Pityrogramma, and Anogramma. The New World genera Jamesonia and Eriosorus form a monophyletic group, and Pterozonium is more closely related to the Old World genera, Austrogramme, Syngramma, and Taenitis.

A contribution to the study of the gametophyte's morphology and development of some species of Thelypteris Schmidel (Thelypteridaceae). The development and morphology of the sexual phase of five species of the Thelypteridaceae family is described and compared. Spores were sown in Thompson medium with agar, germination occurred after 11 days; all spores of the species studied are monolete, ellipsoid with a pleated perine, brown to dark brown; the germination pattern is Vittaria type and the prothallial development is Aspidium type. Gametangia are of the common type of the leptosporangiate ferns. Sporophytes in Thelypteris reptans var. reptans and T. tetragona appear 90–285 days after sowing; T. dissimulans, T. piedrensis and T. oviedoae did not develop any sporophytes. The sexual phase of these species has many morphological characteristics in common with species of the Old and New Worlds.