Reproductive strategies in lichens are a rarely studied field, and little is known about which variables affecting the production of reproductive structures are most important. Here, we investigated how lichen size and cardinal direction affected the density of apothecia in the cyanolichen Leptogium marginellum. We hypothesized that larger thalli and thalli facing south (towards the pole) would have a higher density of apothecia. Individuals with larger body sizes may store more resources that can be invested in sexual reproduction, and thalli facing south in the southern hemisphere could be exposed to more favorable abiotic conditions, similar to the north in the northern hemisphere. We collected L. marginellum thalli along a stream in a protected southeast Brazil area. Cardinal directions and the largest diameter of each thallus were registered with a GPS and a digital pachymeter, respectively. We observed the thalli with a stereomicroscope, delimited a region of 1×1 cm, and photographed it to count the number of apothecia with ImageJ. We found that cardinal direction did not affect the body size or the density of apothecia. However, lichen size was an important variable in the density of apothecia, explaining almost 60% of the variation observed. According to our findings, reproduction can be considered an allometric process, and reproductive patterns can vary with the hemisphere where the lichen is found. To our knowledge, this is the first research studying reproductive allocation in a tropical lichen.

Rhizoplaca ouimetensis is described new to science, growing on outcrops of diabase sills in the Lake Superior region of Ontario, Canada. It is the first known sorediate species of the genus, and a phylogenetic reconstruction based on the ITS and mtSSU markers place it in the R. chrysoleuca group. Morphologically, however, it resembles sorediate, yellow-green species of Lecanora with usnic acid, e.g., L. handelii and L. soralifera, but differs from those in forming larger, often pulvinate or minutely peltate areoles with a well-developed upper cortex and a medulla densely filled with calcium oxalate crystals.

Physcomitrium pygmaeum is an ephemeral moss described in 1871 from a single collection from Utah, currently considered conspecific with Physcomitrium pyriforme. The interpretation of the taxon has been problematic due to its rarity in the field, the elusiveness of the type material, and an extremely scattered and inconsistent collection record. Here we present a comprehensive description and assessment of the taxon following the identification of the original material and lectotype designation, the examination of all existing herbarium specimens to the best of our knowledge, the collection of fresh material in Nevada, and the molecular barcoding of the latter using four plastid and two nuclear loci. Available information, albeit scant, suggests that this member of the North American bryoflora should be considered critically endangered following IUCN criteria.

In this study we present an analysis of the Pyrenula ochraceoflava group (Pyrenulaceae), focusing on the Neotropics and based on morphological, chemical, and molecular data of the mtSSU, nuLSU and ITS markers. We described three new species from tropical dry forests of Mexico, confirm the monophyly of the P. ochraceoflava group and provide evidence for the inclusion of species currently placed in the genus Mazaediothecium within Pyrenula. Pyrenula aurantiacoretis sp. nov. is characterized by an orange pigment covering the thallus in net-like fashion, muriform ascospores with 4 rows of 1–4 cells each, 12–15.5 × 8–10.5 µm, and 7-chloroemodin and emodin as major compounds. Pyrenula connexa sp. nov. is closely related to Mazaediothecium album, being characterized by mazaedioid pyrenocarps, basal and lateral excipular carbonization, highly variable mature ascospores, 1-septate to submuriform, thallus with abundant white verrucae, and lichexanthone as major compound. Pyrenula moldenkeorum sp. nov. is characterized by an orange thallus, submuriform ascospores that frequently show pigmented septa forming a cross septation pattern, 7.5–11 × 5.5–8.5 µm in size, and 7-chloroemodin and emodin as major compounds. The taxonomy of the most common and widespread species of the group, P. ochraceoflava and P. ochraceoflavens, is briefly discussed, presenting evidence to support the consideration of P. ochraceoflava as a species complex. The two species Mazaedothecium album and M. mohamedii are transferred to Pyrenula as P. aptrootiana nom. nov. [non Pyrenula alba (Schrad.) A.Massal.] and P. mohamedii comb. nov.

Anacamptodon splachnoides is an uncommon moss almost entirely restricted to water-filled treeholes in deciduous trees in eastern North America and Europe. There has been uncertainty regarding taxonomic placement of the genus because of conflicts between gametophytic characters, in which it resembles Amblystegiaceae, and sporophytic characters, which seem to ally it with Fabroniaceae, Campyliaceae, or other families. Recent evidence from DNA sequencing clearly places Anacamptodon in Amblystegiaceae despite features of the sporophyte such as an erect capsule, rostrate lid, reflexed peristome teeth, and low endostome membrane. All these unusual features, including sticky spores (which seem to have been overlooked), are characteristic of species of Splachnaceae, until now the only group of mosses whose spores are known to be dispersed by flies. Field observations of A. splachnoides over a period of 16 months revealed that the moss mat and sporophytes are regularly visited by many species of flies that are also treehole specialists. Of 12 species of flies captured, nine carried spores of the moss. Many of these are strong fliers with hairy legs and bodies that inadvertently pick up the sticky spores, dispersing them in a directed fashion to other treeholes, where the females lay eggs that develop into aquatic larvae that later emerge as adults. Though differing in some respects from the adaptations seen in Splachnaceae, the parallel evolution of sporophytic characters related to entomophily is remarkable. In addition, we consider other aspects of the ecology of this moss that may help explain its rarity, such as treehole location, pH of rainfall versus stemflow and treehole water, and a possible beneficial relationship with certain wood-rotting fungi.

Two new species belonging to the lichen genus Anaptychia are described from western North America. Anaptychia nevadensis is superficially similar to the Eurasian A. desertorum but is distinguished by having longer ascospores, in producing scant pruina only near the lobe tips, and in regularly producing variolaric acid. Anaptychia roemerioides is described to accommodate North American material which has previously been called A. ulotrichoides. It is macro-morphologically identical to the Asian species A. roemeri but differs in having longer ascospores and conidia. Both new species are strongly supported by phylogenetic analysis of ITS sequences. We also call attention to the existence of a further undescribed but possibly cryptic species within A. elbursiana. Variolaric acid is newly reported to occur occasionally in A. desertorum and A. elbursiana. A global key to the desert species of Anaptychia is provided.

Following 5 different rates of 1-week desiccation to which Porella platyphylla (a desiccation-tolerant leafy liverwort) was subjected, physiological recovery upon rehydration (after 1 h, 24 h, 48 h) in light was monitored by cytological, photosynthetic (e-transport rate, photoprotective mechanisms), and other metabolic parameters using nuclear- and chloroplast-encoded protein synthesis inhibitors and a violaxanthin cycle inhibitor (DTT: dithiothreitol). Desiccation tolerance is mainly constitutive in P. platyphylla, allowing survival of rapid drying, and employs an active rehydration-induced repair and recovery mechanism. Following 24 hours of rehydration after the one-week dehydration in laboratory air (∼35% relative humidity /RH/), the chloroplasts had an irregular round shape. The recovery within 1 h of the thylakoid-function-related photosynthetic processes was extremely fast and independent of protein synthesis, while the overall recovery (except plants dried up at 76% RH, which depended on protein synthesis only to a limited extent) required de novo protein synthesis during rewetting. During the course of rehydration protein synthesis affects rehydrin expression, osmolite and general carbohydrate metabolism, the main repair and antioxidant mechanisms. Recovery was the best in samples dried up at 76% RH. Membrane permeability increased upon rehydration following 1-week dehydration. Normal membrane function recovered after 24 h (max. 48 h), except in plants that suffered drastic dehydration. Total protein content of plants dried under different conditions and of samples taken during recovery was generally lower than in the control plants at full turgor. The xanthophyll cycle has a great importance during the recovery in light; we confirmed the existence of a greater zeaxanthin-dependent and a smaller zeaxanthin-insensitive NPQ (nonphotochemical quenching). Plants dried under more favorable conditions had better light protection. The highest values of the osmotic potential belonged to the plants subjected to intense dehydration. Total soluble carbohydrate content was well-balanced and seemed to be unchanged following the different treatments. There was a significant increase in proline, while total fructan showed lower values at different degrees of 1-week desiccation. The cytoplasmic protein synthesis is likely to be involved in the change of the fructan content during rehydration.