Taxonomic significance of palynomorphological characteristics of selected Centranthus (Caprifoliaceae) species

Pollen morphology of herbarium specimens of four Centranthus species (C. ruber, C. longiflorus, C. kellereri and C. calcitrapae) was studied using LM and SEM. The research aim was to provide data on their pollen characteristics and to evaluate the taxonomic value of these data for species-specific identification. Pollen grains are tricolpate, suboblate to prolate (P/E = 0.81–1.42); medium- or large-sized (P = 49.21–90.44 µm; E = 43.89–93.10 µm). Colpi are long or medium-length, wide at equator, tapered to acute or obtuse ends. Exine sculpture is echinatemicroechinate-nanoechinate; echini (1.00–1.39 µm high) and microechini (0.55–0.98 µm) are conical, with straight or convex sides and acute apices, nanoechini are 0.22–0.46 µm high. Most important characters of taxa diagnostic at species level for the taxonomy are: size of pollen and colpi, exine structure, size of echini and microechini, and pattern of tectum in areas between echini. Pollen grains of C. calcitrapae and C. macrosiphon (sect. Calcitrapa) are generally smaller in size than grains of C. ruber, C. longiflorus and C. kellereri (sect. Centranthus). Pollen of C. kellereri was analysed for the first time in the current study.

Vegetation analysis of the subalpine beech forest on the upper forest line in the Julian Alps (NW Slovenia and NW Italy) and in the northern Dinaric Alps

Using hierarchical clustering with unweighted pair-group method with arithmetic mean (UPGMA) we arranged 603 phytosociological relevés of beech forests on the present upper forest line, mainly from the Julian Alps and the Trnovo Forest Plateau (we also included the relevés from the Karawanks and the Kamnik Alps), into 32 clusters. Based on their analysis and comparison with previously described similar (alti)montane-subalpine beech communities we classified most of the relevés into the association Polysticho lonchitis-Fagetum and its new subassociations ericetosum carneae, cardaminetosum trifoliae, luzuletosum niveae, luzuletosum luzuloidis, calamagrostietosum variae, allietosum victorialis, adoxetosum moschatellinae, stellarietosum nemorum and several new variants. The altitude of the studied stands is predominantly 1400 to 1550 m (the upper line is at 1660 m); they occur at all aspects, frequently on steep and very steep slopes, mainly on limestone and dolomite limestone, the predominant soil type is rendzina. These stands are species rich (on average 61 species per relevé, altogether more than 500 vascular plants) and have many species in common with the stands of associations Rhododendro hirsuti-Fagetum and Rhodothamno-Laricetum.

Invasion, distribution and habitat affiliation of Cyperus esculentus, a new weed in Slovenia

Cyperus esculentus (yellow nutsedge) is an alien species that started to spread in arable fields in Slovenia and has already become a noxious weed. In this study we present the spatio-temporal pattern of this invasion in Slovenia. Species was first recorded in 1980 and currently two hotspots are evident (Ljubljana Basin and Posočje). Habitat preferences of Cyperus esculentus and the floristic compostion of invaded plant communities were studied. These communites were compared to similar communities in Slovenia and to so far described vegetation types with dominating Cyperus esculentus in Europe. Based on these analyses we described new weed association, namely Digitario sanguinalis-Cyperetum esculenti.

Morphological variability of Trifolium repens L. (Fabaceae)

The subject of our research was Trifolium repens L. The aim was to assess the level of morphological and anatomical variability among populations from different habitats (meadows, roadsides, subalpine slopes) and different altitudes (891–1881 m) in Brezovica (Sharri Mountain, Kosovo). The investigation covered 26 morphological and anatomical traits in populations from 12 locations. From the results obtained during this research, it can be concluded that there is a significant difference among populations for most micro- and macro-morphological traits. There is also a tendency towards a reduction of most of the average values of the investigated parameters (total plant height, total leaf length, leaf petiole length, peduncle length, fruit weight, number of flowers in an inflorescence, stomata length on the upper leaf surface, and diameter of collateral bundle) in relation to altitude increase. However, trichome length showed consistency and was not affected by habitat and altitude changes. The results also lead to a proposal for taxonomic revision of this taxon.

Stipo pulcherrimae-Festucetalia pallentis Pop 1968 of calcareous petrophytic steppes in Ukraine

Nine hundred and eight-nine relevés from calcareous petrophytic steppes in Ukraine and its adjacent territories were assessed with the help of expert systems to determine the syntaxonomic affiliation of the plant communities at class and order levels. At least 488 relevés belonging to the class Festuco-Brometea were analyzed using the TWINSPAN algorithm, and 8 distinctive clusters were obtained, recognized as alliances of the order Stipo pulcherrimae-Festucetalia pallentis. A new alliance, Bromopsido cappadocicae-Asphodelinion tauricae, was ascribed to the Crimean Mountains and the presence of two alliances, Diantho lumnitzeri-Seslerion albicantis and Genisto tetragonae-Seselion peucedanifoliae, was confirmed as new for this vegetation in Ukraine. Unlike in the Pannonian Basin, Bromo pannonici-Festucion csikhegyensis alliance communities mentioned in the literature do not occur in Ukraine. Centaureo carbonatae-Koelerion talievii has been provisionally transferred from Festucetalia valesiacae to the order Stipo pulcherrimae-Festucetalia pallentis. Furthermore, we distinguished alliances by their geographic locations and their climatic (thermoregime, cryoregime, light in communities) and edaphic (carbonate content, salinity, and acidity) features.

Amaranthus powellii (Amaranthaceae), a new addition for the flora of India and a preliminary list of the Indian Amaranthus species

Three populations of Amaranthus powellii were discovered in Kerala region (SE-India), representing the first record of this species for the national flora. A morphological description based on the Indian plants, as well as ecological data are given. A preliminary list of all the Amaranthus species occurring in India, which was never published during the last 136 years, is also provided.

Further records and new data on the occurrence of Martyniaceae in Tunisia and North Africa

Proboscidea louisianica (Miller) Thell. (Martyniaceae) is newly reported for the flora of Tunisia and North Africa as a naturalised alien. Extensive field investigations in northern Tunisia allowed the discovery of three populations of P. louisianica (Miller) Thell. consisting of 18 individuals found at the edges of “Oued Béja” and at roadside within an irrigated land in Nabeul region, where plant specimens were in flowers and fruits. Moreover, further sites were recorded for another member of the family Martyniaceae (Ibicella lutea (Lindl.) Van Eselt.), already reported and known in Tunisia and Algeria within North Africa. Additional information for both species on their current distribution areas and their habits are provided. Details of their morphological and distinguishing features are illustrated.

Grindelia squarrosa in Ukraine: current distribution and ecological and coenotic peculiarities

Grindelia squarrosa (Pursh) Dunal. (Asteraceae) is a species with high invasiveness capacity in Ukraine, especially in the Steppe zone. The first data on the finding of escaped plants in Europe were recorded in the 40’s of the last century. There were three naturalization centres in Ukraine, from where the species began to spread. In the secondary range in Ukraine, G. squarrosa is characterized by high levels of seed productivity and germination, variable modes of dispersal, wide ecological and coenotic amplitudes and CSR-strategy. The trend continues with the spread of the species in western, north-western and northern directions, and today more than 300 localities confirming this trend are already known. In the past 20 years, 92 new localities have been recorded. G. squarrosa is a transformer, widespread in the southern regions of the Steppe zone. As a result, new plant communities are formed. In general, this species is recorded in communities of five vegetation classes. In terms of ecological indicators, the optimum of the species is in the Steppe zone. It can be predicted that, due to the potential ability of the species to adapt and under the influence of climatic change, there is a higher probability that the species will spread in the future in northern and western directions. The condition for such an expansion is disturbance of meadow-steppe fringe xeromesic communities, with decreased coenotic competition.

Phytosociological analysis of noble hardwood forests (Ostryo-Tilienion platyphylli) in the Karst and its neighbouring regions (SW Slovenia)

In SW Slovenia, at Gora under Železna Vrata and Petnik gorge near Branik – both on the northern edge of the Karst, in the collapse doline Orleška Draga at Sežana and under Brkinski Rob at the contact of the Karst and Brkini Hills, we conducted a phytosociological analysis of the stands whose tree layer is dominated by Tilia platyphyllos, T. cordata, Acer pseudoplatanus, Ulmus glabra, in places also Carpinus betulus and Ostrya carpinifolia, and classified them into three associations, Corydalido ochroleucae-Aceretum pseudoplatani, Paeonio officinalis-Tilietum platyphylli and Fraxino orni-Aceretum pseudoplatani. The latter was described as a new. Also new is a secondary large-leaved lime association Lamio orvalae-Tilietum platyphylli on the sites of montane beech forests (Lamio orvalae-Fagetum) in the Čepovan valley, at the contact of the Dinaric and sub-Mediterranean phytogeographical regions of Slovenia.

Conservation, restoration and biodiversity of Palaearctic grasslands – Editorial to the 6th EDGG special issue in Hacquetia

This special issue is a collection of articles about the conservation, restoration and biodiversity of Palaearctic grasslands and was initiated by the Eurasian Dry Grassland Group at the 15th Eurasian Dry Grassland Conference (EDGC), held at Graz, Austria in 2019. The papers in this special issue cover a range of grassland habitats from montane dry grasslands to lowland sandy grasslands, feathergrass steppes and meadow steppes, and focus on the biodiversity values, conservation issues and restoration prospects of Palaearctic grasslands. We hope that the articles in this special issue will contribute to a better understanding of the ecology of grasslands and support their more effective conservation.