The features of xylem tracheary elements in some herbaceous members of the family Convolvulaceae Horan.

Numerous narrow xylem tracheary elements (tracheids and vessels) are present in liana stems, along with a few wide vessels that perform the main water-conducting function. This trait, known as “vessel dimorphism”, has been identified in studies on water-conducting tissue in autotrophic plants, including a large number of perennial climbing plants and a number of annual vines. Information is lacking on the presence of vessel dimorphism in parasitic plants of the lianescent habit. In this study, we performed a structural analysis of stems in the autotrophic herbaceous vines of Convolvulus arvensis L. and Calystegia sepium (L.) R. Br., as well as in the parasitic vines of Cuscuta monogyna Vahl, Cuscuta planiflora Ten., Cuscuta approximata Bab., and Cuscuta campestris Yunck., of the family of Convolvulaceae Horan. The xylem of C. arvensis and C. sepium contains a few wide conductive elements and many narrow ones. This feature is typical of autotrophic climbing plants. Only narrow tracheary elements are present in the xylem of the parasitic vines of the genus of Cuscuta L. (dodders). The total number of the tracheary elements is an order of magnitude less in the dodders than it is in the autotrophic vines. It is possible that the autotrophic ancestor of dodders lost the characteristic feature of the xylem of climbing plants, known as vessel dimorphism, during its transition to the parasitic lifestyle.

Hyalesthes obsoletus is an active vector of Wood blackening in the Republic of Moldova

Hyalesthes obsoletus (Signoret) is an important vector of Wood Blackening in the Republic of Moldova. To identify the causes of the epidemiology of this disease in vineyards, the period of flight and the preference of the host plant H. obsoletus in the field were studied. Monitoring of vineyards showed that this species was found on the Field Bindweed (Convolvulus arvensis L.), and during the period of mass flight, the leafhopper was observed on Xanthium strumarium and Gorets bindweed (Fallopia convolvulus L.). The captured leafhoppers were diagnosed with the presence of Bois Noir stolbur phytoplasm (STOL). The adults of H. obsoletus were also caught from other herbaceous plants: Povoy fence (Calystegia sepium L.), Garden quinoa (Ariplex hortensis L.), Sow thistle (Sonchus oleraceus L.), Medicinal dandelion (Taraxacum officinale L.), as well as c Stinging nettle (Urtica dioica L.). Changes in climatic conditions in the region, causing premature drying of the grass cover, forces cicadas - vectors to switch to actively growing plants during this period, including grapes, which contributes to the widespread of the disease.

Long-Term Control of Hedge Bindweed (Calystegia sepium L.) with Single, Tank Mixture, and Sequential Applications of Glyphosate, 2,4-D, and Dicamba

Hedge bindweed (Calystegia sepium L.) is a widespread troublesome perennial weed species that has strong rhizome regenerative capacity. Four pot trials with randomised, complete block designs were conducted in 2015 to evaluate long-term control of hedge bindweed using individual, tank mixture, and sequential applications of selected herbicides. Two different formulations of N-(phosphonomethyl) glycine (glyphosate; isopropylamine, trimesium salts) were applied at 2000 g active ingredient (a.i.) ha−1. Additionally, two synthetic auxins were applied as 3,6-dichloro-2-methoxybenzoic acid (dicamba) at 500 g a.i. ha−1 and the dimethylamine salt of (2,4 dichlorophenoxy)acetic acid (2,4-D) at 1000 g a.i. ha−1. Tank mixtures and sequential applications (12/24 h separation) of these different herbicides were also included. Long-term control of hedge bindweed, Calystegia sepium L., growth was evaluated 8 months after treatments, as comparisons of shoot and rhizome growth (biomass) between untreated and treated plants. There were no differences between the two formulations of glyphosate alone, with shoot and rhizome biomass reductions of 83% and 42%, respectively. Dicamba alone inhibited shoot and rhizome biomass by 86% and 67%, respectively. By itself, 2,4-D provided the greatest reductions in shoot and rhizome biomasses, 93% and 79%, respectively. Antagonism was seen in the tank mixtures of glyphosate and dicamba or 2,4-D. Tank mixtures were generally comparable to treatments of glyphosate alone, and were less effective compared to dicamba or 2,4-D alone. The greatest reduction of bindweed rhizome biomass was for sequential glyphosate trimesium salt followed by 2,4-D 12 h later, thus showing significantly greater efficacy over glyphosate isopropylamine salt (94% vs. 84%; p ≤ 0.05). These data for reductions of the growth of the rhizome biomass show that the sequential application of glyphosate followed by 2,4-D significantly improves long-term control of hedge bindweed.

Thecaphora seminis-convolvuli. [Descriptions of Fungi and Bacteria].

A description is provided for Thecaphora seminis-convolvuli, found from infected flowers of Calystegia sepium. Some information on its associated organisms and substrata, dispersal and transmission, economic impacts, habitats and conservation status is given, along with details of its geographical distribution (North America, USA (California, Oregon, Washington), Asia (China, Republic of Georgia, Japan), Australasia (Australia (Tasmania), New Zealand), Europe (Austria, Belgium, Bulgaria, Croatia, Czech Republic, Denmark, Estonia, France, Germany, Hungary, Italy, Poland, Romania, Russia (Tula), Sweden, Switzerland, Ukraine, UK)).

Phytocoenotic diversity and dynamics of the communities of association Caricetum gracilis Savich 1926 under the xerophytization of the Desna River floodplain

The paper presents the results of a comparative analysis of the floristic and phytocoenotic diversity within widespread association of acute sedge meadows Caricetum gracilis Savich 1926 in the floodplain of the Desna River (Bryansk and Smolensk regions, Russia). Available geobotanical data on Desna floodplain, collected in the last 40 years, allowed identifying the main dynamic trends in the syntaxonomical space. Based on 36 relevés made by the authors in 1975–1990 previously (Bulokhov, 2001) 3 subassociations, which communities were prevalent in the Desna valley, were established: Caricetum gracilis typicum, С. g. oenanthetosum aquaticae, С. g. beckmannietosum eruciformis. As a survey of the Desna floodplain in 2015–2018 showed, both flow decrease and drop in the level of spring flood and groundwater in the XXI century have led to a change in the appearance, floristic composition, and structure of acute sedge meadows. Xerophytization of the floodplain resulted in the disappearance of the С. g. oenanthetosum aquaticae and С. g. beckmannietosum eruciformis communities. Drying of typical habitats of moist acute sedge meadows became the background of the formation of diverse communities of other types in their place. In the coenoflors of these communities changes occurred at the class level from Phragmito-Magnocaricetea Klika in Klika et Novák 1941 to Molinio-Arrhenatheretea Tx. 1937. Two groups of communities have been formed. The first group is represented by syntaxa of the alliance Magnocaricion gracilis (class Phragmito-Magnocaricetea): Caricetum gracilis typicum with variant Achillea salicifolia as well as by the communities Lythrum salicaria, Calystegia sepium, Calamagrostis canescens. The share of the alliance characteristic species in their coenofloras is 54–64%, and Carex acuta, as a rule, dominates. The second group represents the communities of wet meadows (order Molinietalia caeruleae) of the class Molinio-Arrhenatheretea. The alliance Deschampsion cespitosae is established with subass. Poo palustris–Alopecuretum pratensis typicum (with three variants: Veronica longifolia, Hierochloё odorata, Galium physocarpum) and three communities (Cirsium arvense, Lysimachia vulgaris, Stachys palustris) The share of characteristic species of the order in their coenofloras is 58–95%. All communities and variants form series along the moisture gradient in habitats of acute sedge meadows. Communities Lythrum salicaria, Calystegia sepium, Calamagrostis canescens are distributed in the wettest and richest in mineral nitrogen habitats in the Middle Desna area, in the former long-flooded low-level floodplain. The other ones occur, first of all, in the Upper and Middle Desna areas on a short- and long-flooded floodplain of an average level. These communities are forming on moist and fresh soils. The variants and communities on the gradients of moisture and the richness of mineral nitrogen of the soil were ordinated using the ecological scales of H. Ellenberg et al. (1992). Serial communities form an ecological-dynamic sere on a humidity gradient, showing the direction of their dynamics. The same localization of studies carried out both in 1975–1990 and in 2015–2018 identified changes in vascular plant coenoflora of the ass. Caricetum gracilis for this period: from 62 species in 1975–1990 to 143 species in 2015–2018. There are three groups of species, which reflects these changes. Besides species affine to the class Phragmito-Magnocaricetea, numerous meadow herbs of the class Molinio-Arrhenatheretea appeared: Agrimonia eupatoria, Agrostis tenuis, Bromopsis inermis, Carex praecox, Dactilys glomerata, Dianthus deltoides, Elytrigia repens, Equisetum arvense, Festuca pratensis, Galium mollugo, Geranium pratense, Galium physocarpum, Hieracium umbellatum, Hierochloё odorata, Lathyrus pratensis, Odontites vulgaris, Poa pratensis, Potentilla argentea, Potentilla erecta, Phleum pratense, Vicia cracca. A complex of ruderal explerent and nitrophilous species with numerous alien ones has been formed: Bidens frondosa, Chamaenerion angustifolium, Cirsium arvense, Echinocystis lobata, Epilobium adenocaulon, E. collinum, E. pseudorubescens, E. tetragonum, Erigeron annuus, E. canadensis, Lactuca serriola, Linaria vulgaris, Senecio jacobaea, Sonchus arvensis. Most of these species are anemoсhores, and their presence in the sedge communities is associated with open site formation due to the soil drying between hummocks, as well as the destruction of sedge tussocks under drying and fire. Over the past decade invasive species Bidens frondosa, Erigeron annuus subsp. septentrionalis, E. canadensis,and Lactuca serriola have become an ordinary component of the Desna’s river valley flora. Trees and shrubs (Acer negundo, Betula pendula, Frangula alnus, Quercus robur, Rosa majalis, Salix cinerea, S. pentandra, Swida alba) enter into meadow communities because the lack of haymowing. The following changes in the life form spectrum took place due to the floodplain xerophytization and acute sedge meadow transformation: the proportion of long-rhizome species decreased, while that of rod-root, short-rhizome, and annuals increased; trees and shrubs appeared. Obvious also are changes in the ecobiomorphspectrum: the proportion of mesomorphic species increased, that of hygromophic and mesogygromorphic ones decreased; xero-mesomorphic plants appeared.

Calystegia sepium – an expansive weed of maize fields near Krakow

The aim of the present study was to assess the degree of colonization of maize fields by the greater or hedge bindweed, <em>Calystegia sepium</em> L. in the vicinity of Krakow, and to investigate the habitat preferences of this weed. On the basis of field trips, carried out in 88 fields of maize, we found that <em>C. sepium</em> had colonized approximately 30% of the fields investigated. On average, it covered 17.5% of the field area. Multivariate analyses (PCA and RDA) showed that the presence of this species was correlated with that of sandy soils as well as the proximity of streams. Analysis of the morphological features revealed that <em>C. sepium</em> specimens growing both in fields and in natural stands share similar morphological characteristics.

Asteretum lanceolati: Xenospontaneous community on wet and riparian habitats

Invasive species Aster lanceolatus grows on moist habitats on the whole territory of Serbia. In Belgrade, this species is recorded with a higher degree of presence at a number of localities. With the aim to investigate the community in which this species is dominant, the wide area of Serbia was researched, and 8 localities on the territory of Belgrade were chosen for the analysis of the community. Floristic structure of the community was determined by the standard Braun-Blanquet method (1964), phytogeographical analysis was performed according to Gajic (1980, 1984), and determination of life forms according to Raunkier (Ellenberg, Mueller-Dombois, 1967). pH soil analysis and electric conductivity (EC) were performed at all investigated localities. It was established that the community dominates the moist habitats of Belgrade. It is composed of 104 species and among them Aster lanceolatus Willd., Cichorium intybus L., Agropyrum repens (L.) Beauv., Calystegia sepium (L.) R. Br., Cirsium arvense (L.) Scop., Symphytum officinale L. and Rumex obtusifolius L. are the most frequent. In relation to life forms, the community has hemicriptophytes character, and in relation to phytogeography Euroasian and Middle Europaean floral elements are dominant, with a high presence of cosmopolitan and adventive floral elements. On the locialities Veliko Ratno ostrvo (island) and Makis, EC values point to the fact that the amount of nutrient in the soil is higher than at other localities.