Based on the study of type material of Neotropical Lejeuneaceae, the following new combination and synonyms are proposed: Ceratolejeunea temnantha (Spruce) comb. nov. (basionym: Lejeunea temnantha), Lejeunea huctumalcensis Lindenb. et Gottsche (= Hygrolejeunea grossereticulata Gottsche ex Steph., = H. sacculata Steph., = H. wrightii Steph.), Lepidolejeunea involuta (Gottsche) Grolle (= Hygrolejeunea glaziovii Steph.), Mastigolejeunea plicatiflora (Spruce) Steph. (= Lejeunea plicata Spruce). Ceratolejeunea temnantha is described and illustrated.

A new species of Lejeuneaceae from montane cloud forest of Colombia and Costa Rica, Harpalejeunea scabra, is described and illustrated. The new species is characterized by the papillose dorsal leaf surface, a feature occurring in several related genera such as Lejeunea and Drepanolejeunea, but new to Harpalejeunea. Further diagnostic characters of H. scabra include the dorsal leaf margin with 1–3 teeth and the peculiar lobule with twinned apical teeth, free margin bordered by very narrow cells and aperture circular with the distal end of the apical margin adnate to the surface of the lobe. The new species somewhat resembles the enigmatic Drepanolejeunea navicularis Steph. from páramo of Colombia and Venezuela. The affinities of the two species are discussed.

The spore output of 26 selected species of 11 genera of Lejeuneaceae was investigated by the direct artificial counting method. The mean spore output per capsule ranges from 257 in Cololejeunea magnilobula to 5038 in Ptychanthus striatus. Compared with other leafy liverwort families, Lejeuneaceae have a much lower and more stable spore output. Out of eight species of Ptychanthoideae, Acrolejeunea pusilla is the only species with a mean spore output of less than 1000 spores per capsule. Acrolejeunea securifolia, Cheilolejeunea larsenii and Cololejeunea furcilobulata are reported for China for the first time.

The essential oil composition of the moss Rhodobryum ontariense obtained by hydrodistillation was preliminary analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Thirteen compounds (86.41% of the total oil) were identified. The main chemical constituents were phytol (31.95%) and 1-octen-3-ol (15.44%). Such an abundance of phytol has not yet been reported in other mosses. Four chemicals (cis-decahydronaphthalene, allo-hedycaryol, jasmone and 2,5,5,8a-tetramethyl1,4,4a,5,6,7,8,8a-octahydronaphthalene-1-carboxylic acid, methyl ester) are first records, not only for the genus Rhodobryum and mosses in general, but also for the group of bryophytes as a whole.

Plant rarity is considered a useful predictor of the extinction risk of species. However, apparent rarity can emerge from incomplete data sets or incorrect sampling. Epiphyllous bryophytes are a poorly collected and taxonomically complicated group, with incompletely known distribution patterns. In this paper we explore the diversity patterns and meso- and micro-habitat specialization of common and rare epiphyllous bryophyte species, and evaluate the threat status of Aphanolejeunea gracilis, Leptolejeunea tridentata, and Otolejeunea schnellii. Epiphylls were collected from 240 samples (10 ×10 cm) in 30 plots of 5 ×5 m in superhumid lowland forest of the Chocó, Colombia. Our results indicate that epiphyll diversity and species composition is similar among palm and non-palm leaves. Disturbance had a negative effect on epiphyll cover, species richness, and diversity of rare species. Data on rare species did not correlate with global or national red lists, indicating that detailed surveys are necessary to accurately assess the threat status of “rare” species.

Based on recent bryophyte collections, the presence of Nardia insecta Lindb. and Tritomaria scitula (Taylor) Jörg, from one locality in the Catalonian Pyrenees is indicated, being their first records for Spain. Data on their ecology are included and their conservation status discussed.

Pohlia laticuspis (Broth.) P. C. Chen ex Redf. et B. C. Tan, a species described from China, is conspecific with the neotropical P. oerstediana (Müll. Hal.) A. J. Shaw. The original material of Webera paupera Müll. Hal. ex Paris, an undescribed species from the Himalayan region of India, also represents this species. The previous known geographical range of P. oerstediana is thus remarkably extended to Asia and the species is established as an eastern Asian — northern Latin American disjunct. A map of its global distribution is presented.

An updated catalogue of the bryophytes of São Tomé e Príncipe Archipelago is presented. Occurrence data on both islands for each species are reported, based on a critical assessment of the literature since the first botanical expeditions in the 19^th century up to June 2010. The references are chronologically listed for each species, and all old herbarium specimens revised or identified are also indicated. In addition, two lists (mosses and liverworts-hornworts) of known synonyms are provided.

Two hundred twenty bryophyte taxa are listed (91 mosses and 129 liverworts-hornworts), while twenty taxa are excluded or their occurrence considered very improbable. The species diversity and endemics are also analysed for each island.