The exact distribution of Ranunculus strigulosus Schur is poorly known in Hungary. Current occurrence data of the species mainly from Békés county and only one archive data from the Nyírség region, from the 1920s were known. This study presents eleven newly discovered occurrences in East Hungary. Populations were found in wet meadows, forest glades and poplar plantations. Nine of these populations are located at the southeastern edge of the Nyírség region and most of them are quite small. Three larger population were found in Nyírábrány, Álmosd and the Tócó Valley between Debrecen and Hajdúböszörmény. One of the newly discovered populations provides a new contribution to the flora of Bátorliget Marsh and Fen-wood NCA. Some morphological characters (hairs on the stem and the leaves, shape of the leaves developed before and after the mowing) are also discussed.

The Pannonian swallow-wort (Vincetoxicum pannonicum (Borhidi) Holub) is endemic to the Pannonian biogeographical region, occurring only in the Buda and Villány Mts in Hungary. Current distribution and population size of this rare plant species is surveyed. The species is recorded from the following localities: Budajenő: Községi erdő, Budaörs: Szekrényes, Kő-hegy, Odvas-hegy, Szállás-hegy, Út-hegy, Páty: Fekete-hegyek; Nagyharsány: Szársomlyó. According to our research, the total number of individuals is around 3550. The largest populations were found at Községi erdő (Budajenő), Szállás-hegy (Budaörs) and Fekete-hegyek (Páty). In the Villány Hills (Mt Szársomlyó) ca 50 specimens were counted. The peak flowering period of Vincetoxicum pannonicum was observed between 20^th and 29^th of May.

In the course of our research of Hungarian transport routes, we observed an intensive spread of the Atlantic-Mediterranean Plantago coronopus L., a recently established species in Hungary. Between 2017 and 2019, it was detected in 47 flora mapping quadrats, which increased the total number of occurrences to 81 since 2013. Besides motorways, the main Hungarian transport routes were involved as well. 26 occurrences have been recorded along the roads 4/E60, E573, 8/E66, 86/E65 and 87, which are severely affected by international traffic. However, on routes avoiding international transit traffic, the species’ occurrences are still rare. In some cases, the predominant direction of traffic appeared to influence the formation of new stands. It is very likely that the first individuals that appeared along the section of the M86/E65 motorway between Szombathely and Hegyfalu in 2019, arrived primarily by northbound traffic, rather than along the road 86, which runs parallel to it only a few hundred meters away. Likewise, it seems certain that the spread of the species along the roads M1/E60, E75 (Mocsa, Tata, Páty) and M7/E71 (Fonyód, Balatonlelle, Kajászó) as well as the road 8/E66 (Bakonygyepes, Veszprém) is due to reproduction of older extensive local populations. At several localities along the outer bend of roundabouts or near the exits of motorways, a dispersal role of intense winter road salting was also observed. The largest populations were located mostly along ditches, next to the (often bare) lane of roadbeds that are heavily affected by mechanical and osmotic stress. The majority of stands were found within a 3 meters wide belt along the asphalt strip (5 meters was measured in the lawn of a cemetery once). Since the species is present continuously at several localities since 2013, it is considered as naturalised in Hungary, and its further spread can be confidently predicted. The current status of the species in Hungary is naturalised (non-trans¬former) neophyte.

Eriochloa villosa (Thunb.) Kunth was recorded for the first time in Hungary in 2007. Since then, the species spread intensively in the area and appeared at some other parts of Hungary. We car­ri­ed out a research at the current distribution range of the species in the northern part of Borsod-Abaúj-Zemplén county. We asked how big is the infested area surrounding the place of the first occurrence and whether other occurrences could be found in other parts of the investigated area. This article also gives a review on its known localities in Hungary and neighbouring areas. During the field research, 58 locations of the species were identified, it occurred mainly in ploughed and unploughed agricultural fi­elds, and at some places in disturbed grasslands, too. It has spread on a large scale around the ne­igh­bo­uring areas of the first location found in 2007. Other locations were also found even at more distant pla­ces such as in the valley of the Sajó and Bódva rivers and in the Cserehát region. This means that further spread of Eriochloa villosa can be expected, especially in areas with an intensive agricultural activity, in disturbed grasslands, and a threat of its appearance is also suspected in open natural habitats.

In our paper, we publish the most important new floristic data from the region of Tokaj Hills and Zemplén Mountains (incl. Szerencsköz, Hernád-mente, Bodrogköz, Tatkaköz, Harangod) from the last ten years. During this period, we discovered two new protected species (Asplenium javorkaeanum, Epipactis nordeniorum) in the Zemplén Mountains and seven new protected species (Cep­ha­lan­thera damasonium, Cirsium brachycephalum, Epilobium palustre, Epipactis palustris, Lycopodium cla­va­tum, Pyrola rotundifolia, Polystichum aculeatum) in the Hungarian part of Bodrogköz. We found new lo­ca­tions of several rare species (Epipactis exilis, Dryopteris expansa, Blechnum spicant, Androsace maxima, Orchis coriophora, Orchis purpurea, Dactylorhiza sambucina, Sonchus palustris, Cicuta virosa). We confirmed the occurrence of four species, which have not been detected for decades (Sedum his­pa­nicum, Erysimum wittmannii subsp. pallidiflorum, Pseudolysimachion spurium, Botrychium lunaria).

In this paper the white poplar riparian forests (Senecioni sarracenici-Populetum albae) growing on the Csepel-sziget and its vicinity are described and characterized based on 25 phytosocio­logical relevés. These communities grow on loose fluvial sand and raw alluvial soils on the elevated parts of the lower river floodplain. They can readily be distinguished from willow gallery forests (Leucojo aestivi-Salicetum albae) which have no shrub layers and grow in habitats 1–1.5 m below the level of poplar forests on rather heavy and muddy soils. They differ also from the oak-ash-elm forests (Scillo vindobonensis-Ulmetum) growing in the upper floodplain. Certain – partly submontane – plants that are rare or completely absent in other parts of the Great Hungarian Plains may also occur in them, such as Anemone ranunculoides, Carex remota, Clematis recta, Crataegus × degenii, Crataegus nigra, Epipactis helleborine, Equisetum hyemale, Galanthus nivalis, Lathraea squamaria, Leucojum aestivum, Paris quadrifolia, Scilla vindobonensis, Vitis sylvestris. This association is classified in the sub-alliance Populenion nigro-albae Kevey 2008 in the syntaxonomical system.

In this paper a short review of the nomenclature and etymology, taxonomy, morphology, histology, life cycle, phenology, reproduction, habitat preference, biotic interactions, biologically active compounds, micropropagation, applications possibilities and conservation status of snake's head fritillary (Fritillaria meleagris L.) can be found. Refining of the European distribution area and contributions to the distribution in Hungary are also presented. Primer seed-set, thousand-seed weight, soil charac¬teristic and demographic data are published.

This paper is the 10th in the series aiming to contribute with new distribution data to the maps published recently in Atlas Florae Hungariae. Distribution data of 686 plant species from 194 flora mapping units are published in this study, but all of them are listed in an electronic appendix. As a result of local surveys, more than 100 new species were found in a single flora mapping unit. Other “linear surveys” along the National Blue Trail revealed 142 new species in 10 flora mapping units in total. Among these, Carex strigosa is one of the most interesting taxa in the Bakony Mts. Previously published and new distribution data of this legally protected sedge species suggests that it is spreading from SW to NE within the Transdanubian Mts. Results from our survey shows that studying synanthropic habitats like frequently used hiking trails might provide a significant amount of new data points at the scale of Hungarian Flora mapping units. Moreover, similar studies might shed some light on the origins and migration routes (e.g. Illyrian and Dacian routes) of “native” species.

A new occurrence was found of the rare non-native species, Cycloloma atriplicifolia (Spreng.) J. M. Coult. in the Northern part of Kiskunság, Hungary on 02.07.2019 on a sandy road [N 47.297476°, E 19.382936°, KEF: 8782.1]. This is 80 km apart from the first and until now single occurrence of this species in Hungary. The authors removed the individuals, however, some seeds could remain in the soil. It is assumable, that the species was spread by wheels of the car used by the authors, as they visited the original occurrence of the species and the new one during the autumn in 2018 with the same car. This new occurrence draws attention to an important, but overlooked invasion pathway: to the invasion with cars of ecologists.