The fourth edition of the Red List of Liverworts and Hornworts of Poland was prepared using the rules presented in the 2nd edition of the International Union for Conservation of Nature Red List Categories and Criteria (version 3.1). Altogether, 240 liverwort and four hornwort species that are currently found in Poland are included. Seventy-two species (71 liverworts and one hornwort) are classified as threatened, which comprises 30% and 25% of the liverwort and hornwort flora, respectively. The critically endangered (CR) category is assigned to 11 liverworts and one hornwort, the endangered (EN) category is assigned to 21 liverworts, and the vulnerable (VU) category is assigned to 39 liverworts. Two liverwort species, Anastrophyllum donnianum and Biantheridion undulifolium, are considered regionally extinct. Data concerning the distribution, abundance and population state of 21 species (20 liverworts and one hornwort) fall within the data deficient (DD) category; in this category, the data are insufficient for the established criteria to be used to determine the endangerment category. One liverwort is included in the not applicable (NA) category.

After the discovery of two Macromitrium species with aristate leaves, new to science, in New Caledonia, another aristate species, M. panduraefolium, is described and commented on herein. It is distinguished from the formerly known species by its smaller size, leaves spirally coiled around the branch axis and branch leaf shape narrower at the middle. Its ecology and its status are discussed. In addition, the author provides a key to the aristate species known from the region including Malesia, Australasia, Pacific Islands and Melanesia.

A morphological comparison between Targionia hypophylla L. and T. stellaris Hässel is carried out based on fertile material from northern Argentina. The two species differed in a large number of gametophytic traits, including: epidermal pores, antheridia location and ventral scales shape. The spores of T. stellaris are also described in detail and compared to those of T. hypophylla; their potential taxonomic value is discussed in depth. The first photomicrographs of T. stellaris are provided.

The moss Bryoerythrophyllum latinervium var. rotundatum X.L.Bai, D.M.Ren et L.Q.Yang is described as a new variety from Inner Mongolia, China. It is distinguished from Bryoerythrophyllum latinervium (Holmen) Fedosov et Ignatova by its rounded leaf apex. Light microscope photographs of the significant characters are provided and its distinctions from closely related taxa are discussed. A key to the Chinese species of Bryoerythrophyllum is provided.

Ulota panchengiana Q.H.Wang & Y.Jia is described and illustrated as a new species from China. It is characterized by both stomata that are scattered throughout the urn and by naked calyptra, two remarkable characters that are rarely found in Ulota species from the northern Hemisphere. Ulota panchengiana is easily recognized by the combination of the following characters: lanceolate leaves with an ovate base, the presence of a few rows of hyaline cells at the basal leaf margin, and long seta. The ecology, geographical distribution, variation, and morphological comparison with related taxa are discussed. Ulota morrisonensis, endemic to Taiwan, is easily misidentified as U. crispa. However, based on a study of an isotype of the former species and in response to a recent reevaluation of the circumscription of U. crispa, we confirm its rank as a species and discuss obvious morphological differences between the two species. A revised key to Chinese Ulota species is provided.

Radula deflexilobula Promma, L.N.Zhang et R.L.Zhu is described and illustrated as a new species from Thailand. This species is distinctive in 1) the presence of dimorphic leaf lobules that are subrhombic and strongly reflexed on pendulous shoots, subquadrate and not reflexed on creeping shoots; 2) leaf lobules covering the stem ca. 1/3–1/2 of the stem-width, not auriculate at base, and 3) leaf cells thin walled with indistinct trigones and smooth cell surface. Our phylogenetic analyses based on three chloroplast regions (trnG, trnL-F, atpB-rbcL) confirm that this new species belongs to subg. Radula and is sister to R. decurrens Mitt. known from Fiji.

Macromitrium fortunatii Thér. was included in the first Red List of Chinese endangered bryophytes, but later its inclusion was considered as uncertain because of taxonomic uncertainty and insufficient distribution data. Though the species was recently excluded from the latest threatened species list of China's higher plants, no detailed geographical records, voucher specimens or relevant references were included. From our morphological studies of type and other specimens, together with phylogenetic analyses based on ITS2, trnL and trnG sequences, we confirm its taxonomical identity and provide a detailed description and illustrations of the species. Macromitrium fortunatii var. nigrescens Tixier is reduced to synonymy with M. fortunatii. Since 2013 we have found 24 populations of M. fortunatii in Southwest and South China and North Vietnam. According to nine environmental variables and recent records of the species, we predict its potential distribution range with an aid of the maximum entropy algorithm modeling program (Maxent) and ArcGis 10.2. We find a high environmental suitability of the species in a wide region covering South and Southwest China, North Vietnam, North Myanmar, Nepal, and Northeast India. The predicted climate suitability for M. fortunatii is highest in areas where the annual precipitation is 1200 mm, the driest quarter receives 50 mm, and the wettest month 250 mm, the mean temperature of the coldest quarter is 10°C, and the altitude is about 1200 m. The exclusion of M. fortunatii from the threatened species list of China's higher plants is supported.

Riccardia is a large genus of thalloid liverworts and notoriously difficult in terms of species recognition. Thirty six species were recognized in the tropical Andes but many of these are not well-defined. In this paper fourteen species are accepted for Colombia and Ecuador; eighteen species and two varieties are reduced to synonymy. Descriptions and illustrations are provided for the accepted species together with a key and data on types, synonymy, geographical distribution, habitat and differentiating characters. Riccardia palmata and R. multifida are excluded from the flora of Colombia and Ecuador. The new combination Riccardia latifrons subsp. parasitans (Steph.) Gradst. & Reeb comb. nov. is proposed and eighteen new lectotypifications are made.