Hans H. Blom

DNA barcoding of European Herbertus (Marchantiopsida, Herbertaceae) and the discovery and description of a new species.

DNA barcoding of a group of European liverwort species from the genus Herbertus was undertaken using three plastid (matK, rbcL and trnH‐psbA) and one nuclear (ITS) marker. The DNA barcode data were effective in discriminating among the sampled species of Herbertus and contributed towards the detection of a previously overlooked European Herbertus species, described here as H. norenus sp. nov. This species shows clear‐cut differences in DNA sequence for multiple barcode regions and is also morphologically distinct. The DNA barcode data were also useful in clarifying taxonomic relationships of the European species with some species from Asia and North America. In terms of the discriminatory power of the different barcode markers, ITS was the most informative region, followed closely by matK. All species were distinguishable by ITS alone, rbcL + matK and various other multimarker combinations.

Community assembly in epiphytic lichens in early stages of colonization

Colonization studies may function as natural experiments and have the potential of addressing important questions about community assembly. We studied colonization for a guild of epiphytic lichens in a former treeless heathland area of 170 km2 in southwest Norway. We investigated if epiphytic lichen species richness and composition on aspen (Populus tremula) trees corresponded to a random draw of lichen individuals from the regional species pool. We compared lichen communities of isolated young (55-120 yr) and old (140-200 yr) forest patches in the heathland area to those of aspen forest in an adjacent reference area that has been forested for a long time. All thalli (lichen bodies) of 32 selected lichen species on trunks of aspen were recorded in 35 aspen sites. When data for each site category (young, old, and reference) were pooled, we found the species richness by rarefaction to be similar for reference sites and old sites, but significantly lower for young sites. The depauperated species richness of young sites was accompanied by a skew in species composition and absence of several species that were common in the reference sites. In contrast, genetic variation screened with neutral microsatellite markers in the lichen species Lobaria pulmonaria showed no significant differences between site categories. Our null hypothesis of a neutral species assembly in young sites corresponding to a random draw from the regional species pool was rejected, whereas an alternative hypothesis based on differences in colonization capacity among species was supported. The results indicate that for the habitat configuration in the heathland area (isolated patches constituting < 0.4% of the area) lichen communities may need a colonization time of 100-150 yr for species richness to level off, but given enough time, isolation will not affect species richness. We suggest that this contradiction to expectations from classical island equilibrium theory results from low extinction rates.

Two new rheophytic species of Schistidium (Grimmiaceae) from China

Abstract Two new species of Schistidium Bruch & Schimp., S. riparium H.H.Blom, Shevock, D.G.Long & Ochyra, and S. mucronatum H.H.Blom, Shevock, D.G.Long & Ochyra, are described and illustrated. They occur in rheophytic habitats in China, S. riparium in the southern Hengduan Mountains in Yunnan Province (Lancang Jiang and Nu Jiang catchments) and S. mucronatum from further north, on the Qinghai–Tibet Plateau of Sichuan and Qinghai Provinces (Jinsha Jiang and Huang He catchments). The affinities of the new species are discussed and on the basis of their concave and broadly canaliculate leaves with plane and erect margins, S. riparium is tentatively placed in Schistidium Bruch & Schimp. subgen. Canalicularia Ochyra, whereas S. mucronatum on account of its keeled, ovate-lanceolate leaves and the strongly curved and twisted peristome teeth resembles very much species of sect. Apocarpiformia (Kindb.) Ochyra within subgen. Apocarpa Vilh.

Degelia cyanoloma (Schaer.) H. H. Blom & L. Lindblom comb. et stat. nov ., a distinct species from western Europe

Degelia cyanoloma (Schaer.) H. H. Blom & L. Lindblom is resurrected from synonymy and elevated from varietal rank to species. The taxon was earlier referred to D. plumbea (Lightf.) P. M. Jorg. & P. James, however, several discontinuous character states distinguish the two species. Degelia cyanoloma is characterized morphologically by having a large thallus that is pale greyish when dry, lobes that are composed of consecutive trough-shaped segments with an upper surface without squamules, no isidia or soredia, and apothecia discs that are dark reddish brown to blackish. Degelia cyanoloma has a euoceanic distribution and is known from western Europe (Norway, France, Great Britain, Ireland, Portugal, Spain). Based on results from studies of morphology, we hypothesize that D. atlantica (Degel.) P. M. Jorg. & P. James is the closest relative of D. cyanoloma among the European species of the genus whereas D. plumbea is closely related to D. ligulata P. M. Jorg. & P. James.

Colura calyptrifolia a new oceanic liverwort to Norway and Scandinavia

Colura calyptrifolia is for the first time reported from Scandinavia, it was discovered in Femanger, Fusa municipality, Hordaland county. C. calyptrifolia was growing on an east to northeast facing cliff by a small brook. It was found mainly growing directly on the cliff, but small patches were also found on twigs of Lonicera periclymenum.

Xanthoria calcicola (Teloschistaceae, Ascomycota) still present on bark in Sweden

For almost twenty years Xanthoria calcicola was considered extinct on bark in Sweden. Here, we report X. calcicola growing on bark at 14 localities in Skåne, southernmost Sweden. In total, ca 300 thalli were observed on bark, and the populations vary from 1 to 200 thalli. In all localities except one X. calcicola was also present and more abundant on neighboring substrates made of stone, such as churchyard walls, church walls or tombstones. Preliminary results from fungal ITS data reveal that haplotypes found on bark are always present in the surrounding wall populations. We conclude that trees are suboptimal habitats for X. calcicola and only colonized when in close vicinity of an established wall population. The most obvious threat to epiphytic X. calcicola is the cutting down of host trees.