The crustose cyanolichen Fuscopannaria frullaniae (syn. Moelleropsis nebulosa subsp. frullaniae) is a poorly understood taxon that occurs on mosses and liverworts, described from eastern Canada and reported from the Iberian Peninsula, Macaronesia and the eastern USA. Originally placed in the genus Moelleropsis, the position of the species has been debated in the absence of sexual fruiting structures and, until now, DNA sequences from the fungal symbiont. We produced nine sequences from two fungal ribosomal loci from F. frullaniae collected at five different localities in Nova Scotia, Canada and North Carolina, USA. Initial BLASTn queries against public databases revealed high similarity between these sequences and basidiomycete sequences from the Dictyonema clade in Hygrophoraceae, specifically from the genus Acantholichen. We did not obtain ascomycete sequences from any locus or specimen. Phylogenetic analyses recovered the obtained sequences within the broader Acantholichen clade. We conclude that the lichen fungal symbiont is in fact a basidiomycete and introduce for it the new combination Acantholichen frullaniae. Acantholichen frullaniae is the first species of the genus to possess a granular, crustose thallus. The species lacks the characteristic, spiny, balloon-shaped cells called acanthohyphidia that are found in other species of the genus, though it possesses similar, albeit spineless cells on the surface of thallus granules; we suggest that these structures within the wider genus are homologous and represent spiny or smooth cystidia. Numerous samples yielded evidence of basidiospores and basidia produced from thallus granules, evident only after treatment with diluted potassium hydroxide, representing the first sexual structures reported in the genus. We discuss the possible reasons for this, as well as the ecology and threats to the species across its Canadian populations.

Twenty-five years ago, the dripzone hypothesis, whereby the proximity of understorey conifer branches to the crown of dominant Populus trees significantly increased the diversity and abundance of cyanolichens on these conifers, was first described from western North America. Here, we report a similar phenomenon from eastern North America on conifers under the dripzone of yellow birch and aspen trees. We present field observations of this pattern as well as a quantitative analysis of three humid boreal forests from the Island of Newfoundland. For the latter, we examined epiphytic lichen composition on branches of balsam fir within and immediately outside the dripzone of yellow birch trees. The dripzone effect was strong and spatially restricted to the area under the canopy of yellow birch, as well as aspens, on wet sites in humid forests, with significantly more cyanolichens on balsam fir branches under the yellow birch and aspen canopies. Genera of cyanolichens predominantly found under the dripzone included Fuscopannaria, Leptogium, Lobaria, Lobarina, Neproma, Pannaria, Parmeliella, Pectenia, Pseudocyphellaria and Ricasolia, and included the COSEWIC listed Pectenia plumbea. We suggest here that the canopy of broadleaf phorophytes not only shape the cyanolichen community on understorey conifers by chemical enrichment of the throughfall, but also probably from enrichment by cyanolichens within their own canopy, which also contribute abundant cyanolichen propagules.

The population dynamics of the epiphytic lichen Lobaria pulmonaria were studied in spruce forests within Paanajärvi National Park (Karelia), which has seen no major disturbances during the last 190 to 270 years. Studies for the period 2015–2021 showed a rise in thallus number and area, with a larger proportion in the ontogenetic spectrum being young, non-reproductive thalli (virginal 1). Sexual reproduction was low, with fertile thalli comprising less than 1% of the total. Salix caprea and Populus tremula trunks served as the main growth surfaces for Lobaria pulmonaria in the northern taiga forests. Furthermore, Salix caprea offered the optimal environment for thalli to grow and develop. In a few instances, the colonization of new substrata was observed. Climate change is expected to have a positive impact, allowing the species’ range expansion at its northern border.