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We present a description of the new species Rhynchostegium occultum from central Chile, including illustrations, a distribution map, and preliminary molecular data that supports its taxonomic placement. The new taxon is restricted to coastal relict forests of central Chile. An overview of the Chilean taxa of Rhynchostegium, and a key for local species are also provided. The new combination Rhynchostegium corralense, and new synonyms for Rhynchostegium acanthophyllum and for Cratoneuropsis chilensis are proposed. Oxyrrhynchium hians is newly reported for Chile, apparently being a recent introduction. Lectotypes are selected for Hypnum corralense, Hypnum acanthophyllum, and for Rhynchostegiella acanthophylla var. robusta.

Two closely related tropical genera from the pleurocarpous moss family Neckeraceae are revised: the second largest genus in the family, Neckeropsis , currently with 29 species, and Himantocladium , comprising six species. Twenty-one species of Neckeropsis and five of Himantocladium were included in this study, which is based on phylogenetic analyses using sequence level data from the plastid ( rps4 ) -trnT-trnL-trnF cluster and rpl16 as well as nuclear ITS1 & 2. Neckeropsis appeared as polyphyletic. Neckeropsis s. str. comprises 12 species and a further four species, not included in the analysis, are tentatively retained in the genus based on morphology. Four new genera are segregated from Neckeropsis : Pengchengwua (with one sp.), Planicladium (two spp.), Pseudoparaphysanthus (five spp.), and Neckeromnion (five spp.). Neckeropsis gracilis is synonymized with Neckeromnion urocladum and reported for the first time from Laos. Four molecular analyzed species are resolved in the Himantocladium s. str. clade, with a fifth species being added solely on morphological basis. Himantocladium formosicum is transferred to Neckeropsis . Leaf-like paraphyses (ramenta), unique in Neckeropsis s. str. , have evolved two times. In addition, the rare Noguchiodendron sphaerocarpum from the Himalayan region, the single species in its genus, was included in a phylogenetic analysis for the first time and it was found to be closely related to the Asian genus Taiwanobryum .

The taxonomic position of Rhynchostegiella acicula , a local endemic of Shaanxi Province of China, is investigated by means of cladistic analyses employing nrITS sequences. The analyses show that R. acicula does not belong to Rhynchostegiella s.str. (Helicodontioideae) but is resolved within the Homalothecioideae as sister to Eurhynchiastrum , from which it differs by a soft and slender habit; narrow lanceolate and acuminate leaves; a percurrent costa; and an autoicous condition. It differs from Brachytheciastrum and Brachythecium in a longly rostrate operculum, and from Homalothecium in a small plants that lack thick-walled basal laminal cells characteristic of this genus, as well as in an autoicous inflorescence. As a consequence, R. acicula is transferred into its own, monospecific genus Frahmiella Ignatov, Vanderpoorten & Wang You-fang, gen. nov.

The systematic position of the moss genus Acrocladium Mitten is reviewed and previous family placements are evaluated. A molecular dataset spanning five genomic regions from all three genomes was developed to address the relationships of Acrocladium . The results indicate a sister group relationship with Lepyrodontaceae, rather than with the Lembophyllaceae or Amblystegiaceae, as previously suggested. The strong differences in the morphologies of Lepyrodon and Acrocladium warrant recognition of the latter at family level: Acrocladiaceae R. Tangney, D. Quandt, S. Huttunen and M. Stech, fam. nov.

The presence of short inversions in non-coding plastid DNA is universal and an integral part of its evolution. We studied the effect of these structural changes in phylogenetic inference by measuring phylogenetic accuracy as a topological congruence among topologies inferred from plastid and nuclear sequences in ferns ( Lindsaea ) and mosses (Brachytheciaceae). We randomly replicated ten subsets of both groups and tested the performance of various coding schemes and phylogenetic methods. Our results demonstrate that short inversions do interfere with phylogenetic analysis, leading into incongruent topologies. The phylogenetic accuracy was increased by removing inversions or applying various coding schemes to them. Parsimony analyses resulted in greater accuracy than maximum likelihood or Bayesian analyses, but this was at least partly explained by slightly poorer resolution of parsimony trees. Due to the great importance of non-coding plastid DNA in species-level plant systematics and the frequency of structural rearrangements in it, we recommend these kinds of data be carefully explored before analysis, and the possible rearrangements to be optimized.