This paper presents the first comprehensive overview of the currently known Rubus taxa of the Bohemian Forest (= Böhmerwald, Bayerischer Wald, Šumava), a mountain range located in central Europe that extends across Austria, Czechia and Germany. The study is based on a detailed field survey conducted between 2019 and 2023 and subsequent evaluation of published and database records. A total of 60 species and one hybrid of brambles are accepted for the study area. The treatment of each taxon comprises a reference to a morphological description and illustration, a description of the overall distribution, a characterization of the distribution in the study area, including a classification into regional phytochorotypes, an elevation maximum occurrence, a grid distribution map, and a list of herbarium specimens and accepted records. A total of 30 species are documented for the first time from the study area. Furthermore, the following five species are described as new to science: R. bicoloristylus, R. cammensis, R. depressinervius, R. parvidentatus and R. suavis. The morphology, drawings, photographs of holotypes and species in situ, taxonomy, ecology and overall distribution including distribution maps of these species are provided. The lectotypes of eight taxa previously described from the Bohemian Forest are designated: R. heterophyllus Utsch including its two forms, R. hirsutus J. Presl et C. Presl, R. kuenicus Utsch including its three varieties and R. plicatus f. brevispinus Tocl. A critical evaluation of the literature, databases and herbaria revealed that records of 152 taxa previously reported from the Bohemian Forest are not acceptable based on current taxonomic and chorological knowledge. The majority of these erroneous records are attributed to misidentifications, which are explained by a lack of knowledge about the variability and plasticity of individual species and the application of inappropriate taxonomic approaches. The list of unaccepted taxa, accompanied by their original localities, is provided, along with a commentary on the reasons for their rejection. From the perspective of regional biodiversity, brambles represent an essential plant group that is largely a result of regional speciation processes. This is demonstrated by the prevalence of taxa with a central European distribution pattern (44 out of 56 recorded native species). Of these, 25 are endemic to the study area and adjacent areas.

Epiphytic bryophytes are susceptible to air pollution. The disappearance of sensitive species from highly polluted areas and their recovery after a decrease in pollution were recorded in the second half of the 20th century in Europe. However, the effect of current air pollution on the composition of epiphytic communities and the associated role of host-tree bark chemistry have not been sufficiently studied. Here, the effects of acidifying air pollution on the structure of epiphytic bryophyte communities hosted by tree species with different bark pH are assessed. Due to the higher acid-buffering capacity of basic substrates, a smaller difference between communities on host trees with high bark pH in areas with different pollution loads was expected. Epiphytic bryophytes were studied at 50 sites with similar climate but contrasting levels of SO2 and NOx air pollution in central Europe. As a proxy for the current pollution load at each site, in addition to SO2 and NOx atmospheric concentrations, tissue N concentration was measured in Hypnum cupressiforme. Abundances of species of bryophytes were recorded on trunks of oaks (Quercus robur and Q. petraea, low bark pH expected) and ash (Fraxinus excelsior, high pH expected). Ninety species of bryophytes were recorded. Acidifying air pollution still influences the structure of epiphytic bryophyte communities in Europe, despite the lower levels of pollutants than previously. Atmospheric concentration of SO2 was found to be a significant environmental variable affecting structure of epiphytic bryophyte communities. Ash with high bark pH hosted more diverse communities, including sensitive species, but were just as affected by SO2 pollution as oaks. Species richness, occurrence of epiphytic specialists, and diversity of epiphytic bryophyte communities decrease with increasing SO2 pollution, both on oak and ash. However, it is likely that acidifying air pollution is not the sole driver of the structure of current epiphytic communities in central Europe.

Feather grasses (Stipa) are among the most typical constituents of steppe vegetation. Enigmatic S. epilosa, which was suggested to occur in various parts of the Alps, differs from common S. eriocaulis in the micromorphology of the cross section of its leaves. The rib flanks of the upper leaf surface lack the dense hairs typical of S. eriocaulis; instead, they are covered by short cone-shaped papillae. Populations of Stipa in the Vinschgau Valley in South Tyrol and the upper Inn Valley and Wipptal Valley in North Tyrol were studied using morphometric analysis of leaf cross sections, AFLP fingerprinting and microhabitat analyses. The following specific questions were addressed: (i) Is S. epilosa genetically divergent from S. eriocaulis? (ii) Are micromorphological differences between S. eriocaulis and S. epilosa consistent? (iii) Are there microhabitat differences between S. eriocaulis and S. epilosa, potentially reflecting adaptation of papillose and hairy individuals to different environmental conditions? First, this study revealed no genetic difference between S. eriocaulis and S. epilosa in the Eastern Alps. Second, there is a continuum in the variation in hair lengths from typical S. epilosa to typical S. eriocaulis, which makes it difficult to differentiate between two discrete groups. Finally, no microhabitat differences were recorded between papillose and hairy individuals. From a taxonomic point of view, our integrative approach combining genetic, morphometric and microhabitat data failed to support the hypothesis that S. epilosa is an independent taxon in the area studied.

Grasslands are global hotspots of biodiversity, but in many regions the abandonment of traditional management has led to secondary succession and the disappearance of specialized grassland species. An example of such a species is the burnt-tip orchid Neotinea ustulata (syn. Orchis ustulata), formerly known from ~130 sites across Poland, which has experienced a rapid population decline. However, the species and the reasons for its disappearance have not yet been the subject of comprehensive ecological research in Poland. Therefore, in the present study we sampled Polish localities of N. ustulata outside the mountainous areas where its presence has been reported in the 21st century and collected both population and ecological data. Besides describing the current distribution and ecological niche of the species in Poland, we aimed to identify environmental conditions at both local (vegetation and soil) and regional (landscape and climate) scales that favour the survival of the most viable populations of N. ustulata. Of the 24 localities confirmed in the 21st century, we found no individuals of N. ustulata in eight during our survey in the spring and summer of 2022, while further six populations were much smaller than in previous inventories. One population, located in an active quarry, could not be surveyed. Only nine populations of N. ustulata were found to be relatively stable. Compared to extinct and declining populations, stable populations of N. ustulata occupied unshaded xeric grasslands on shallow soils in areas with a more arid climate. Our study suggests that, due to ineffective or non-existent conservation efforts, habitat extremity appears to play a crucial role in the continued survival of this species in Poland.

The Ranunculus trichophyllus group has a complex evolutionary history and remains taxonomically unresolved. In central Europe outside the Alps, two tetraploid cytotypes distinguished as R. trichophyllus A and B have been recognized in previous studies. Another ecologically specialized taxon, R. confervoides (R. trichophyllus subsp. eradicatus), is reported to have a disjunct distribution in northern Europe, the Alps and Pyrenees, and mountains and northern regions of Asia and North America. However, the classification of the populations outside northern Europe as R. confervoides has recently been questioned. We studied the R. trichophyllus group in 35 lakes in the Alps and five in northern Europe, involving genome size determination, sequencing the nuclear ITS region and two non-coding plastid DNA regions, and recording 10 morphological characters. The populations referred to as R. confervoides in the Alps did not substantially differ from the northern European ones morphologically, had identical genome size and shared the plastid haplotypes and ITS genotypes with them. Consequently, we consider the northern and the Alpine populations to belong to the same species R. confervoides. Interestingly, we also identified plants that combine morphological characters of R. confervoides and R. trichophyllus A, even though the latter was not found in the Alps during our study. Their status remains unclear; they may represent hybrids, but partly they can be a manifestation of morphological plasticity of these taxa. Nine plastid haplotypes were observed in R. confervoides and the “intermediate” populations, which contrasts with only two haplotypes identified in each of the two R. trichophyllus cytotypes outside the Alps.

The fourteenth part of the series on the distributions of vascular plants in the Czech Republic includes grid maps of 103 taxa in the genera Achnatherum, Adonis, Consolida, Corallorhiza, Cypripedium, Dianthus, Glaux, Inula, Juncus, Laser, Linum, Mahonia, Malaxis, Mercurialis, Nassella, Ononis, Pseudorchis, Pyracantha, Rosa, Rubus, Sagina, Samolus, Smyrnium, Spiranthes, Stipa and Traunsteinera. These maps were produced by taxonomic experts based on examined herbarium specimens, literature and field records. The spectrum of taxa includes various ecological groups. Rare habitat specialists are represented by the halophytes Glaux maritima, Juncus gerardii and Samolus valerandi, psammophytes Dianthus arenarius subsp. bohemicus and Stipa borysthenica, petrophytes Dianthus gratianopolitanus, D. lumnitzeri and D. moravicus and the serpentinophyte Dianthus carthusianorum subsp. capillifrons. Additional rare and declining species are among orchids, weeds of arable land, and plants of dry grasslands, thermophilous oak forests and subalpine habitats. Three of the included taxa are Czech endemics (Dianthus arenarius subsp. bohemicus, D. carthusianorum subsp. sudeticus and D. moravicus) and two subendemics, with ranges extending into bordering countries (Dianthus carthusianorum subsp. capillifrons and Rubus brdensis). Altogether, half of the mapped taxa are on the national Red List. Alien species are also represented in this paper. The previously introduced neophytes Mahonia aquifolium, Pyracantha coccinea, Sagina apetala and Smyrnium perfoliatum have started to spread in recent decades. Nassella tenuissima has begun to escape from cultivation. In contrast, some formerly more common weeds of arable land have been declining in recent decades. Spatial distributions and often also temporal dynamics of individual taxa are shown in maps and documented by records included in the Pladias database and available in the Supplementary materials. The maps are accompanied by comments that include additional information on the distribution, habitats, taxonomy and biology of the taxa.

Pulsatilla grandis is a symbolic species of dry grassland ecosystems and indicates the importance of diverse management strategies for its conservation and protection of the associated biodiversity. Despite being classified as of Least Concern on the IUCN Red List, there has been a significant decline in its native dry grassland habitats due to habitat degradation, abandonment and eutrophication. This study investigates the population dynamics and conservation status of this threatened vascular plant, focusing on data for flowering individuals, threats and site characteristics collected over 19 years from 420 Czech populations. Employing two imputation models to address missing data, this study reveals a considerable decrease in flowering plants, with 17–20% of populations experiencing complete loss of flowering individuals within the period monitored. The total loss of flowering individuals in the Czech Republic is estimated to be between 23 and 46%. Although management efforts have doubled, factors limiting species survival, like litter accumulation and dispersal and spread of invasive species, continues to have a serious effect on habitat quality. This study underscores the need for ongoing and increasing efforts in conservation and habitat management in order to prevent further decline of this and other related dry grassland species in the Czech flora.

Recent data and syntheses in central Europe have led to the development of synthetic variables for describing the successional orderings of species. In particular, the “successional optimum” (SO), developed for describing the vegetation in the Czech Republic, reflects the number of years it takes for a species to reach peak abundance after a disturbance. The aim is to combine data on a species’ functional traits and Ellenberg-type indicator values, in order to identify the main plant strategies and environmental factors that predict SO. In this study, linear models with regularization techniques and robust inference methods were used to determine the traits that explain species’ SO, and then an analysis of the explained variance was used to assess the relative explanatory power of each trait. In parallel, the effects of Ellenberg-type indicator values, before and after detrending the SO by traits, were determined. This revealed that five traits had the greatest and most consistent effects: therophytic life form, seed mass, flowering duration, bud bank size and leaf dry matter content. The most important Ellenberg-type indicator values predicting SO were moisture and reaction, as light and nutrient concentrations were associated with these traits. The effects of traits were generally consistent and universal in the different environmental conditions, as the interaction of traits and environment did not change inferences or result in better models. This resulted in a robustly defined strategy that relates species to their successional ordering, highlighting the importance of life forms, competitive abilities, and reproductive strategies in succession.

Three alien Solidago species of North American origin have become naturalized in Europe. While S. canadensis and S. gigantea are considered among the most aggressive plant invaders, S. altissima is rarely found. Here, the detailed karyological variation and cytogeography of alien Solidago species in central Europe and the genetic relationships among the cytotypes is elucidated in their native and other invaded areas. Almost 4,800 plants from 800 sites across central Europe were studied using flow cytometry and complementary chromosome counting. A representative subset was sequenced (ITS, cpDNA) and compared with available data. The findings are in accord with previous reports, with the diploids of S. canadensis and tetraploids of S. gigantea dominating the invaded range. There was up to 10% variation in the genome size among the studied populations of particular species, the relationship between genome size and the geographical location and altitude of the population was statistically confirmed. In addition, for the first time in the invaded range, rare cytotypes, i.e. triploids of S. canadensis and pentaploids and aneuploids of S. gigantea, were recorded. The record of S. altissima in the study area was not confirmed and its previous hexaploid record was refuted based on re-examination. The triploids of S. canadensis were represented by scattered plants within diploid populations, and they most likely resulted from an occasional fusion of reduced and unreduced gametes. The origin of the S. gigantea aneuploids and especially pentaploids is more obscure as almost three hundreds were recorded, although so far, only one pentaploid has been reported from North America. Samples from the invaded range shared ITS ribotypes with those from the native range; however, ITS data indicate slight genetic differentiation of pentaploids and aneuploids of S. gigantea. It was also revealed that two widespread haplotypes of cpDNA in central Europe were shared by all cytotypes of S. gigantea and S. canadensis. The cytogeographic pattern of invasive Solidago species in Europe is more diverse than expected. Because genome duplication can promote invasiveness, the origin, distribution and invasive potential of newly discovered polyploids need to be investigated in order to prevent their negative effect on the native flora.