A new species, Didymodon jimenezii J.Kou, X.-M.Shao & C.Feng, is described and illustrated from Dinggyê County in the south Tibet of China. It is characterized by ovate-lanceolate leaves with acuminate or acute apex, lamina yellow with KOH, costa short-excurrent, widest and usually strongly spurred at midleaf, guide cells in 1 (2) layers, without ventral stereids, costal ventral epidermis with a pad of bulging cells and basal marginal cells with regularly thickened transverse walls. The new species is contrasted with similar species in the genus.

Preliminary results are presented of a lichen exploration in Amapá State in Brazil. The following new species are described: Absconditella termitariicola with apothecia immersed to emergent, often partly covered by the thallus, 0.15–0.25 mm diam., pale ochraceous; asci pyriform; ascospores 1-septate, 10–12 × 4.0–5.0 μm, Astrothelium lineatum with orange thallus with orange, often linear pseudostromata with immersed ascomata in groups of 3–15; ascospores 8/ascus, hyaline, regularly muriform, 45–55 × 11–13 μm, without distinctly thickened median septum, Astrothelium unisporum with thickly corticate thallus, high, thallus-covered pseudostroma warts with 1–4 ascomata; ascospores 1/ascus, muriform, 125–148 × 35–42 μm, Coenogonium minidenticulatum with apothecia 0.2–0.4 mm diam., usually distinctly denticulate; ascospores 6–7 × 1.0–1.5 μm, with rounded ends, Crypthonia corticorygmoides with olive green felty thallus, up to 1 cm large white stromatoid-like ascigerous areas and 3–5-septate clavate ascospores of 25–29 × 5–6 μm, Cryptothecia rhizophora with white thallus with long, branching, superficial rhizomorphs of up to 0.2 mm wide, which reach until in the prothallus and ascigerous areas with lichexanthone; ascospores 85–95 × 32–37 μm, Endocarpon riparium with thallus consisting of dense agglutinated flat squamules which are not overlapping, with margins and cracks with numerous 0.1–0.2 mm diam. dorsiventral lobules of thallus-structure that are easily detached and serve as asexual propagules, Psammina tropica with sporodochia abundant in the central part of the thallus, absent in a marginal zone of 1–2 mm wide, whitish grey, irregular to rounded, ca. 0.1–0.3 mm diam., only ca. 15 μm high; conidia hyaline, palmate, with 3–6 arms, each of which are 4–7-celled, ca. 20–25 μm diam., consisting of cells of ca. 2.5–3.0 μm, Thelenella monospora with shiny grey thallus, low conical thallus-covered ascomata and ascospores 1/ascus, hyaline, ellipsoid, irregularly muriform, 75–90 × 25–28 μm, and Thelocarpon triseptatum with minute pallid perithecioid ascomata with flat tops, hamathecium thin anastomosing paraphysoids; ascospores 8/ascus, 3-septate, 12–16 × 3.5–4.5 μm. A further 209 species are reported new to Amapá State, eight are new to the Neotropics, one is new to South America and a further seven are new to Brazil. In Amapá, just as in Rondônia, Astrothelium is the most speciose lichen genus, and this may be the case all over the Amazon.

Recent molecular phylogenetic studies of the lichen family Acarosporaceae have shown that genera in this group, as traditionally defined, are not monophyletic and that changes are required to accommodate the discovery that taxa with disparate thallus morphologies are often closely related. Here we use phylogenetic inferences of mtSSU sequence data to show that seven species (Acarospora dispersa, A. rhizobola, A. terricola, Melanophloea americana, M. coreana, M. montana and Thelocarpella gordensis), currently placed in four genera and three families, and with divergent thallus morphologies, all belong to a single strongly supported clade within the Acarosporaceae. Members of the clade all have apothecia with an incurving parathecium which forms globose apothecia in which the apothecial disc is less than or equal to half the width of the equatorial diameter of the hymenium, and long bacilliform conidia. We transfer the species to Trimmatothelopsis, the oldest generic epithet available for the group and provide a taxonomic treatment that includes analysis of the published literature pertaining to these taxa, a key to species and descriptions of the four taxa that occur in North America. Rhizohyphal bundles are reported from two terricolous species, T. terricola and T. rhizobola.

Marchantia longii R.L.Zhu, Y.L.Xiang et L.Shu sp. nov. (Marchantiaceae) from northwestern Yunnan, China, is described as new to science. It is similar to Marchantia emarginata, but can be distinguished by the large epidermal pore ((108−)150−210 μm in diameter), the acute to obtuse inner margin of surrounding cells of pores in vertical section, the female receptacle dissected (0.2−0.4 of diameter) into 5−7 subquadrate to oblong lobes truncate or rounded apically, and the entire to weakly dentate margin of the appendage of the median scale. A phylogenetic analysis based on DNA sequences of rbcL, trnL–F and nrITS1–5.8S confirms M. longii as a sister to the clade of M. emarginata subsp. tosana M. inflexa M. papillata subsp. grossibarba, and this new species is placed in Marchantia subg. Clamidium.

Megalaria allenae, a blue-gray to green-blue sterile sorediate crustose lichen containing atranorin, fumarprotocetraric acid and zeorin, is described as new to science. It is corticolous on deciduous trees and endemic to swamp forests of the Atlantic Coastal Plain of southeastern North America. As sexual reproductive structures are unknown in the species, the generic placement and relationship with M. pulverea were determined using molecular phylogenetic analyses of ITS and mtSSU sequence data.