Orthotrichum, sensu stricto, is a genus of about 90 species that are mostly adapted to xerophytic environments, occurring on a variety of substrate types, including tree trunks and rock surfaces. However, three species—O. euryphyllum, O. rivulare, and O. sprucei—inhabit seasonally submerged substrates along streams and other water bodies. The morphological similarity and peculiar ecological preferences of these three species have been recognized taxonomically by several infrageneric treatments, in particular as subgenus Rivularium, assuming that the acquisition of the rheophytic lifestyle as a single event. We examined with sequence data from nuclear and plastid markers with the hypothesis that these three species form a monophyletic group. Adaptation to the rheophytic habitat arose at least twice in Orthotrichum and very likely additional times in the subfamily. The subgenus Rivularium, as previously recognized, is not monophyletic and the three rheophytic species should be placed in the type subgenus.

Most taxa of the genus Marchantia L. (Marchantiaceae) produce multicellular gemmae within gemma cups. They are discoid bodies with two notches and a trace of stalk. Although gemmae of Marchantia have been of interest to physiological and developmental studies, they have been rarely used as a taxonomic character. To improve understanding of the taxonomic significance of gemma morphology, we investigated gemmae of six Japanese Marchantia (including four subspecies) and provide comparative morphological descriptions and a key. Several characters of the gemmae, including size, shape, morphology of marginal cells, and the presence or absence of mucilage hairs were useful in species identification. Morphological similarity of gemmae between M. polymoprpha and M. paleacea, as well as between M. emarginata and M. pinnata, was consistent with the results of molecular phylogenetic analyses. We recommend that morphology of gemmae should be used as a new taxonomic character in the genus Marchantia.

Hawaiian mosses identified as members of the genus Glossadelphus by morphological features were examined using two molecular markers (ITS1&2 and trnL-F). Three species of Glossadelphus (G. acutifolius, G. chrysobasilaris, and G. limnobioides) as well as Phyllodon lingulatus and Ectropothecium zollingeri collected from Kauai Island, Hawaii Islands were included in this study. Our analyses showed that all samples of G. acutifolius, G. irroratus and G. limnobioides formed a monophyletic clade with Ectropothecium species. Present results confirmed the synonymy of G. baldwinii with Phyllodon lingulatus. In addition, Glossadelphus chrysobasilaris was revealed to be a member of the genus Symphyodon (Symphyodontaceae) and new combination, S. crhysobasilaris (Broth.) W.Kim & H.Akiyama is therefore proposed.

The following new lichen species are described from the Atlantic rain forest remnant Pedra Talhada (Alagoas, Brazil): Hafellia nortetrapla, with four ascospores per asci, ascospores grey to brown, 1-septate, 30–38 × 13–16 µm, and norstictic acid as secondary chemistry, and Pterygiopsis densisidiata, with an appressed thallus, densely covered with branched isidia, and clearly clustering with species inside the core group of the order Lichinomycetes, as shown by analysis of mtSSU region sequences. A further 19 species are reported as new to Brazil, and 307 new to the state of Alagoas. In total, 442 species have been identified thus far in our collections from Pedra Talhada, and a list of the species is provided.

Several nomenclatural changes in the Hypnales are proposed in order to purify the circumscription of Pseudotaxiphyllum and Taxiphyllum. Three species of Pseudotaxiphyllum (P. falcifolium, P. homomallifolium and P. richardsii) do not fit well in any current genus, or belong to distinctive subgeneric lineages, which necessitates the description of novel taxa (Margrethypnum gen. nov., Redfearnia gen. nov., and Taxiphyllum subgen. Parataxiphyllum subgen. nov.). A fourth species, Pseudotaxiphyllum distichaceum [≡ Stereodon distichaceus], is transferred to Longiella, leaving only species that produce branch-like gemmae in Pseudotaxiphyllum. Five species of Taxiphyllum are transferred to other genera: T. fluitans and T. gabonense to Ectropothecium, T. laevifolium [≡ E. laevifolium] to Phyllodon, T. ligulaefolium [≡ Glossadelphus ligulaefolius] to Mittenothamnium, and T. torrentium [≡ Amblystegium torrentium] to Bryocrumia. A 50-taxon ITS-based phylogeny is included for illustrative purposes. Plagiothecium sect. Stansvikia is established to accommodate a group of medium-sized to large, glossy, autoicous species with an austral oceanic distribution. Included taxa are P. subantarcticum sp. nov. [= P. Donianum sensu Mitten 1869] from Tierra del Fuego, P. falklandicum, P. georgicoantarcticum, P. georgicoantarcticum var. antarcticum comb. nov. [≡ Hypnum antarcticum] from the Kerguelen Islands, and P. novae-seelandiae. Phylogenetically, sect. Stansvikia belongs to the core of the genus and is related to both sect. Plagiothecium and sect. Leptophyllum (P. lucidum s.l.).

The known collections of the genus Cora in continental North America north of Mexico, all restricted to Florida, are shown to belong to a single species, representing a previously unrecognized taxon formally described herein as C. timucua. Based on data of the fungal ITS barcoding marker, obtained through Sanger and Illumina sequencing from two historical collections, the new species is phylogenetically most closely related to C. casanarensis from Colombia and C. itabaiana from Brazil, although it is morphologically most similar to the only distantly related C. hymenocarpa from Costa Rica. Based on data from the Consortium of North American Lichen Herbaria (CNALH) and from the Global Biodiversity Information Facility (GBIF), most of the collections of C. timucua originate from around the turn of the 19th century, while a few were made in the second half of the 20th century, all between 1968 and 1985. Almost all collections originate from Florida sand pine scrub, apparently the preferred habitat of this taxon. Neither modern collections nor extant localities are known. Based on these findings and the substantial degree of land use change in Florida in the past decades, we assessed the conservation status of C. timucua using the IUCN Red List criteria and found that it should be classified as critically endangered (CR), in line with the status of another Florida endemic, Cladonia perforata, which was the first federally red-listed lichen in the United States. The most likely location where C. timucua may still be extant is Ocala National Forest in the north-central portion of the Florida peninsula, although recent macrolichen surveys in that area did not encounter this species.