Contribution to the flora of Asian and European countries: new national and regional vascular plant records, 8

ABSTRACT The paper presents new records of 24 vascular plant species from 11 Eurasian countries. One taxon (Orobanche laxissima) is reported from Armenia; one (Epipactis condensata) from Azerbaijan; two (Phragmites americanus, Polygala multicaulis) from Belarus; one (Stipa caucasica) from Egypt; one (Puccinellia hauptiana) from Kyrgyzstan; three (Aquilegia xinjiangensis, Geranium saxatile, Ranunculus songaricus) from Mongolia; one (Stipa roborowskyi) from Pakistan; three (Echinochloa muricata, Erigeron acris subsp. podolicus, Hypericum majus) from Poland; six from Russia, whereof one (Zanthoxylum armatum) from the European part of Russia and five (Chaerophyllum aureum, Elsholtzia densa, Poa compressa, Ranunculus subrigidus, Viola sororia) from the Asian part of Russia; two (Ludwigia repens, Sagittaria latifolia) from Slovakia; and three (Rubus ambrosius, Rubus camptostachys, Rubus perrobustus) from Ukraine. For each species, synonyms, general distribution, habitat preferences, taxonomy with remarks on recognition and differentiation of the species from the most similar taxa occurring in a given country, as well as a list of recorded localities (often far from the previously known areas), are presented.


Introduction
During field exploration across the vast area of 11 European and Asian countries as well as during taxonomic revisions based on herbarium materials of different groups of vascular plants, the authors found some species that are new to the floras of particular countries or their significant regions (provinces or republics). The paper is the continuation of the previous works (Nobis et al. 2014a(Nobis et al. , 2014c(Nobis et al. , 2015a(Nobis et al. , 2015b(Nobis et al. , 2016(Nobis et al. , 2018, which similarly to the works of Sukhorukov et al. (2016) and Sukhorukov et al. (2017) are dedicated to new national and regional vascular plant records, to broaden from 1000 m up to 4100 m (Li and Hedge 1994). Along with other species of this genus, E. densa is used as an aromatic and medicinal plant, and for this reason it is grown beyond the native area.
The specimens of E. densa were found in the Asiatic part of Russia (Baikal Siberia) during a field trip in 2017. There were ca. 20 blooming plants growing on the bank of the small river, near the motorway on the southern outskirts of the town of Petrovsk-Zabaykalsky.

Taxonomic notes
The genus Elsholtzia comprises about 40 species, most of which occur in Southern and Eastern Asia. In Russia, only four species of this genus have been known so far. These include the widely distributed Elsholtzia ciliata (Thunb.) Hylander, and two species restricted to the southern part of the Russian Far East: Elsholtzia amurensis Probat. and Elsholtzia pseudocristata H. Lev. All three species have secondary spikes. The clear-cut Elsholtzia serotina Kom. has very dense short-cylindrical spikes and large bracts with a long point at the apex (Probatova 1995). Elsholtzia densa is characterized by cylindrical spikes, sometimes interrupted at the base at anthesis and more or less densely villous throughout, and relatively small bracts without a prominent point. This is rather a polymorphic species in terms of leaf blade shape, grade of pubescence, and density of spikes. Some forms were described as varieties or even separate species, e.g. Elsholtzia calycocarpa Diels (= Elsholtzia densa var. calycocarpa Elsholtzia densa is a new alien species to Russia, and second species of the genus Elsholtzia noted in Siberia. Epipactis condensata Boissier ex D.P. Young (Orchidaceae) Contributors -Attila Molnár V., Miklós Óvári, Gábor Sramkó

Taxonomic notes
It is supposed that the closest relatives of Epipactis condensata are Epipactis purpurata Sm. and Epipactis rechingeri Renz (Young 1970;Renz 1978;Renz and Taubenheim 1983;Meikle 1985). The first species differs from the two others by having much more pubescent rachis and ovary, greyish to yellowish green (not violet-tinged) leaves and yellowish green flowers and by the habitat (sparse woodlands instead of shady forests) (Efimov 2008). Epipactis condensata is similar (and probably closely related) to obligate autogamous E. krymmontana, from which it differs by its relatively dense and usually much longer inflorescence, much darker epichile with more protruding bosses and presence of a viscidium (Fateryga et al. 2014).

Distribution and habitat
Geranium saxatile was described by G.S. Karelin and I.P. Kirilov (1842) in Bulletin de la Société Impériale des Naturalistes de Moscou from Dzhungarskiy Alatau (East Kazakhstan). The species is distributed in the territory of Tajikistan, Kyrgyzstan, Kazakhstan and Western China in the Pamir-Alai, Tien-Shan, Tarbagatay and Dzhungarskiy Alatau (Fisun 1963;Nabiev 1983;Novosselava 1996). This species has not previously been found within the territory of Mongolia. It grows in alpine and subalpine meadows, sometimes in the upper part of the tree-shrub zone, in damp places.

Taxonomic notes
Geranium saxatile belongs to taxonomically difficult section Recuvata Knuth and it is a part of the group of kinship of ancient-Mediterranean species Geranium collinum Steph. ex. Willd. Geranium saxatile has strong erect stems; shallow (3/4-1/2) separate leaf blades; umbellate inflorescence concentrated in the upper part of the stem; a relatively large bluepurple сorolla. However, Geranium collinum is characterized by a weak ascending dissection almost to the base of the leaf blades; axillary peduncles, arranged along the entire length of the stem; and pinkish-purple corolla (Fisun 1966;Novosselava 1996). According to our observation, these species differ in size and structure of the sculpture of pollen grains (Troshkina and Ovchinnikova 2017;Troshkina 2017).
New localities of O. laxissima have been found in moist, deciduous forests and shrubs in Syunik Province in Armenia. The species is a new, native taxon to the flora of this country. Populations of the species differ in abundance, comprising from 100 to 300 shoots.
Orobanche laxissima and O. owerinii differ in morphology. The first species has a longer shoot (25-80 cm versus 15-60 cm); longer inflorescence (up to 40 cm, lax, many flowered, usually as long as or longer than the remaining stem versus up to 20 cm, short cylindrical or oval, lax, often few flowered, shorter than or equalling the remaining part of the stem); calyx segments usually bidentate versus entire or rarely bidentate; corolla usually 22-24 cm versus 18-30 cm; anthers and style usually with glandular hairs versus subglabrous; usually longer, broader, semi-orbicular and more crenate lobes than in O. owerinii. They also parasitize different hosts (roots of trees metioned above versus herbaceous Fabaceae), and habitat preferences (moist, shady or semi-shady shrub and deciduous forests versus subalpine meadows).
It is worth emphasizing that both taxa are very polymorphic, especially in coloration, size, number and density of flowers. It is very often much more difficult to distinguish them in herbaria (especially if only single specimens are available) than in the field, because on dried plant material some characters are not clearly visible. Orobanche owerinii is probably closely related to O. crenata and replaces it in the upper montane zone (Novopokrovskij and Tzvelev 1958;Tzvelev 2015). This issue requires further study, including revision of all herbarium materials labeled as O. crenata, or O. owerinii, as well as the whole subsections Speciosae (Beck) Teryokhin and Minores (Beck) Teryokhin, supported by field research and determination of hosts, especially in the Caucasus.
Poa compressa (Canada bluegrass or flattened meadowgrass) is distributed in the temperate zone of Eurasia, being widespread grass in Europe and in the Pacific area (Tzvelev 1976). In spite of being recorded in numerous places in European Russia, it is considered to be a rare plant in the forest zone. It is quite rare in Siberia. Until 2000, there was only one recorded locality near the agricultural experimental station in Eastern Siberia (Olonova 2003). Later, it was found in other regions of the most populated southern part of Western Siberia (Ebel 2013;Olonova and Gao 2014). The species is known in the USA as an invasive one (Whitson et al. 1996;Heffeman et al. 2001) and seems to spread easily in Siberia as well (Olonova et al. 2016). Nevertheless, the species has been reported neither from Arctic Siberia, nor from Krasnoyarsk Kari stretching from the Arctic Ocean southwards to 52°N. In summer 2016, it was collected in Arctic Siberia, in the vicinity of Dudinka on the Yenisei River, in a disturbed plant community near the road in the port.

Taxonomic notes
Poa compressa together with two other species, Poa rehmannii (Aschers. & Graebn.) Woloscz. and Poa taurica H.Pojark., belongs to subsection Tichopoa (Aschers. & Graebn.) Maire of section Stenopoa Dum. (Tzvelev 1976). Poa compressa is the most common and widespread, whereas P. rehmannii and P. taurica are endemic to Carpathians and Crimea, respectively. The species of subsect. Tichopoa differ from other Stenopoa by having strongly compressed culms and nodes, and by being rhizomatous. In spite of being a morphologically variable species, P. compressa can be distinguished from the most similar P. rehmannii and P. taurica by having smooth and glabrous culms under the panicle and a tuft of hairs on the lemma callus. For comparison, the culm of P. rehmannii is hairy under the panicle, and its lemma callus is glabrous; the culm of P. taurica is scabrous.  (Hughes and Halliday 1980;Liang and Tzvelev 2006). During the field research in Middle Asia in 2017, the species was for the first time observed in Kyrgyzstan. Two localities of this taxon were discovered in the central Tian-Shan Mountains where several dozen individuals grew mainly on gravel-stony roadsides and partly spread into directly adjacent meadow communities. Including other Puccinellia species previously noted in Kyrgyzstan (Lazkov and Sultanova 2014), newly found P. hauptiana is the tenth Puccinellia species observed so far in this country.

Taxonomic notes
The genus Puccinellia still requires modern integrative taxonomic revision to verify and clarify the systematic position of many taxa, including Puccinellia hauptiana. Some authors classified this taxon as a separate species (Krechetovich 1934;Tzvelev 1976;Liang and Tzvelev 2006), while others incline to the view that it should be treated rather as a subspecies -Puccinellia distans subsp. hauptiana (Hughes and Halliday 1980;Davis and Consaul 2007

Distribution and habitat
The species was firstly described from Tastau and Dschabyk (Tarbagatai Ridge) in Kazakhstan (Schrenk 1842). In Central Asia this taxon was reported from Kyrgyzstan (Lazkov and Sultanova 2014), Kazakhstan (Gamayunova 1961) and China (Wang and Gilbert 2001). From the territory of Mongolia, Ranunculus songaricus has not been reported yet (Gubanov 1996). However, for the first time Ranunculus songaricus has been recently found in Mongolia and should be now regarded as a new native species to this country. The species is distributed in the alpine zone and grows in meadows and on stony slopes.

Taxonomic notes
According to the "Conspectus of Flora of Outer Mongolia", 25 species representing the genus Ranunculus occur in all provinces (Gubanov 1996).

Ranunculus arschantynicus Kamelin, Schmakov & S.
Smirnov and Ranunculus sapozhnikovii Schegoleva have been described from the Mongolian Altai (Kamelin, Shmakov, and Smirnov 2004;Schegoleva 2006aSchegoleva , 2006b and several other species of uncertain taxonomic status [Hörandl and Emadzade 2012] (Bobrov and Mochalova 2014;Bobrov et al. 2017;Ivanova et al. 2017;Wiegleb, Bobrov, and Zalewska-Gałosz 2017). In Europe, it is known from the most northeastern area (Polar Ural) . Ranunculus subrigidus is absent in the main floristic lists of Siberia (Baikov 2005(Baikov , 2012. Our research presents the first documented location of this species in Altai Territory. Recently, this species was found in the Novosibirsk Region (Kipriyanova 2018). The species mostly shows a continental temperate distribution. It occupies mostly inland areas from arid to subarctic regions, and occurs in lakes, ponds, streams with hard water and even brackish waters .
Ranunculus. subrigidus was confirmed by us in the Kulunda main canal in Altai Territory (West Siberia) in 2014. It formed dense and vast communities with projective cover more than 75% in the depth 0.5-0.8 m.

Taxonomic notes
Ranunculus subrigidus W.B.Drew has been merged in Ranunculus circinatus Sibth. for a long time, in spite of having specific characters such as pyriform nectar pits, hairy leaves, stipules and upper part of stems, as well as softer and sparser leaves. Evidently, both make up a pair of allopatric species. Ranunculus subrigidus W.B. Drew has also been treated as a synonym or a lower rank taxon within Ranunculus aquatilis L. In the last review on aquatic Ranunculus species  the authors distinguish four clades based on morphology, geography, molecular evidence and chromosome number counts, in which R. subrigidus and R. aquatilis are placed in the different clades. Ranunculus subrigidus also differs from Ranunculus longirostris Godr. by larger and wider petals, which have a distinct yellow claw, and pyriform nectar pits. The style of the carpel is less pronounced and sometimes subterminal. In Central Asia R. subrigidus is very similar to Ranunculus sphaerospermus Boiss. & C.I.Blanche; both species have large flowers with pyriform nectar pits and similar general appearance, so frequently they can be distinguished only by size and number of fruits: R. sphaerospermus has numerous (> 50) small fruits (< 1 mm), contrary to R. subrigidus which has less abundant and bigger fruits .

Distribution and habitat
Stipa caucasica is widely distributed in the mountains of Asia, from Minor Asia (Caucasus, Northern Iran) through Turkmenistan, Uzbekistan, Kazakhstan, Kyrgyzstan, Tajikistan, Afghanistan, Pakistan, Kashmir up to China (Tzvelev 1968(Tzvelev , 1976Freitag 1985;Wu and Phillips 2006). It is an important component of different mountainous, subalpine semideserts and woodland communities from about (1200-) 1400 m up to 3500 (-4000) m a.s.l. (Freitag 1985 (Ibrahim, Hosni, and Peterson 2016). Stipa caucasica is a new species to the flora of Egypt.

Taxonomic notes
The examined herbarium specimen had previously been determined as Stipa barbata Desf. although it significantly differs from S. barbata in having unigeniculate awns, hairs on seta 4-6 mm long vs bigeniculate awn with seta hairs c. 1.1 mm long and ligules at the vegetative leaves up to 0.2 mm long, densely ciliated by hairs vs 1-2 mm long ciliate. According to Ibrahim, Hosni, and Peterson (2016), in the locality of Sinai Mt Stipa arabica grows as well. Stipa caucasica and S. arabica differ by the character of awn (unigeniculate, with seta hairs 4-6 mm long vs. bigeniculate, with seta hairs 2-2.5 mm long) and ligules at the vegetative shoots (up to 0.2 mm long, densely ciliated by 1.5-2 mm long hairs vs 4-8 (15) mm long acute, usually short ciliolate).

Distribution and habitat
Stipa roborowskyi is known only from China (western Himalayas). Due to previous misidentification of S. roborowskyi with Stipa klimesii M.Nobis (syn. Stipa basiplumosa var. longearistata; Nobis et al. 2014bNobis et al. , 2015, distribution range of the last species requires detailed examination. After revision of a large number of specimens determined previously as S. roborowskyi, it appears that most of them, collected from China, India, Nepal, Buthan and Pakistan, refer to S. klimesii and only few specimens collected from western China can be identified as S. roborowskyi.
During revision of Stipa species from Pakistan preserved at GOET, we found specimens of S. roborowskyi, and this is the first confirmed record of this species in the country.

Distribution and habitat
Viola sororia, known as the common blue violet, is a species with a natural range in North America. It is distributed in the east of the continent from Canada to Mexico, where it occurs in forests, thickets, moist prairies, on stream banks and coastal shoals, as well as in pastures and on disturbed ground (Britton and Brown 1970;Little and McKinney 2015). It was introduced to the Eurasian countries as an ornamental shade-tolerant species and now is considered as established. The species prefers friable fertile soils. In the European part of Russia, it is known beyond culture in the Moscow region (Mayorov et al. 2012) and in the Republic of Karelia (Kravchenko and Fadeeva 2014). In the Asian part of Russia, V. sororia was for the first time recorded as escaped from culture. In the discovered locality the species is quite acclimatized, forming continuous abundantly blooming tufts.

Taxonomic notes
Viola sororia is a new representative of the genus Viola in Asiatic Russia, where ca. 70 species have been observed so far (Zuev 2012). Viola sororia is a short-stemmed herbaceous perennial rhizomatous plant with heart-shaped long-petioled leaves assembled into a basal rosette and exceeding their length by peduncles with large single flowers. Petal colour of this species in native populations is usually light to dark blue-violet. In culture V. sororia has white petals (sometimes with violet veins), and often much larger flowers. Viola sororia, as well as many other violets, can form cleistogamous flowers (Little and McKinney 2015), therefore the species multiplies successfully not only vegetatively, but also gives a rich self-sowing.

Distribution and habitat
Echinochloa muricata has been a long-overlooked alien which is now more or less widely naturalized in Europe (Hoste 2004). It is a North American species most common in the western part of the United States, where it grows mainly in wet habitats, e.g. in. ditches, sloughs and pond-margins (Fernald 1915). To date, E. muricata has been reported from Austria, Belgium, Corsica, Czech Republic, Denmark, France, Germany, Great Britain and Ukraine (DAISIE 2018; Euro+Med Plantbase 2018). The first locality of E. muricata in Europe was recorded from Belgium in 1887, but the history of introduction and naturalization of this species is unknown (Hoste 2004).
To date, there are five non-native species from the genus Echinochloa that have been noted in Poland (Pacyna 2005). Of this number, only Echinochloa crus-galli (L.) P.Beauv. has been known as established/naturalized and invasive in Poland (Tokarska-Guzik et al. 2012). The other species, Echinochloa colonum (L.) Link, Echinochloa esculenta (A. Braun) H. Scholz, Echinochloa frumentacea Link and Echinochloa microstachya (Wiegand) Rydb. have also been recorded in Poland, but not as permanently established (ephemerophytes) (Tokarska-Guzik et al. 2012). Recently, E. muricata has been found in Poland. Its occurrence in Poland was suggested by Pacyna (2005), but only two years ago (in 2016) we found large and established populations of this species in the Vistula River Valley. Echinochloa muricata and E. crus-galli resemble each other ecologically; however, E. muricata performs slightly better on moister and heavier soils (e.g. in river valleys). Both species are also found on arable land and ruderal, recently disturbed sites, or sometimes in shallow ditches along fields that run dry in summer (Hoste 2004).

Taxonomic notes
Echinochloa muricata is morphologically a rather variable species and at the same time very similar to Echinochloa crus-galli. Echinochloa muricata is characterized by subacuminate fertile lemma with a firmer tip, whereas in E. crus-galli the fertile lemma is subacute or obtuse, with a withering tip (Wiegand 1921). Furthermore, E. crus-galli has a line of minute hairs between body and tip of the fertile lemma, whereas in E. muricata hairs are absent (Fassett 1949).
Hoste (2004) stated that, although E. muricata and E. crus-galli are morphologically variable species, identification is not a serious problem when mature material is available. By carefully looking at the lemma of the fertile flower in E. crus-galli, the distinction between the membranous tip and the coriaceous part is usually clear-cut and visible with a hand lens. Furthermore, a good first indication in the field is provided by the uppermost leaf, which in E. muricata shows a line in the form of an "upside-down U" between blade and sheath. In smaller plants this structure generally results in a stiff, upright position of the blade, whereas in E. crus-galli the upper blade is generally patent to reflexed (Hoste 2004).
There are two varieties of E. muricata: E. muricata var. microstachya Wieg. (= E. microstachya) with spikelets 2.5-3.8 mm long and lower lemmas unawned or with awns to 6 (-10) mm long, and E. muricata var. muricata with spikelets 3.5-5 mm long and lower lemmas with 6-16 mm long awns. However, a distinction between E. muricata var. muricata and E. muricata var. microstachya is not always evident. Echinochloa muricata var. microstachya is gradually spreading and is by far the most common variety, whereas E. muricata var. muricata is only known as a rare casual (Hoste 2004 (Botschantzev 1959;Šída 1998). Its geographical range extends from the steppe and woodland-steppe zone of Russia and Ukraine to the Caucasus in the south, and to the Pannonian Basin in the west (Botschantzev 1959;Šída 1998). In Europe, it was reported from Austria, Slovenia, Croatia, Bosnia and Herzegovina, Montenegro, Macedonia, Serbia, Bulgaria, Hungary, Romania, Moldova, Germany, the Czech Republic, Slovakia, Ukraine and Russia (Greuter 2006). In Poland, E. acris subsp. podolicus has not been recorded so far (Šída 1998;Pliszko 2015Pliszko , 2018; however, considering new data presented herein, it most likely reaches a northern limit of its native range in the southern part of this country. Erigeron acris subsp. podolicus occurs on sandy, saline soils, gravel beds, grassland slopes, forest glades and edges, as well as on outcrops of chalk and limestone (Botschantzev 1959;Šída 1998). According to Šída (2004), it is associated with xerothermic grassland vegetation of Festucion valesiacae.

Taxonomic notes
Erigeron acris subsp. podolicus is an accepted name for one of the members of Erigeron acris L. s.l., following taxonomic treatment of Astereae by Greuter (2003). It belongs to Erigeron sect. Trimorpha (Cass.) DC. which consists of annual, biennial or perennial plants with trimorphic flowers within each capitulum, namely outer female ray flowers with erect filiform lamina, inner female ray flowers without lamina, and typical inner bisexual disc flowers (Nesom 2008 however, its outer ray flowers possess longer ligules (Pliszko 2015(Pliszko , 2016. Moreover, similarly to E. acris subsp. baicalensis and E. acris subsp. serotinus, E. acris subsp. podolicus is densely covered with unbranched multicellular uniseriate non-glandular trichomes on stems, leaves and involucral bracts, in contrast to glabrous or sparsely covered E. acris subsp. droebachiensis (Pliszko 2015(Pliszko , 2016(Pliszko , 2018. It should be pointed out that taxa included in E. acris s. l. show a great morphological variation in the number and shape of cauline leaves, and size and arrangement of capitula, as well as in indumentum (Halliday 1976;Šída 1998, 2000Pliszko 2015Pliszko , 2016Pliszko , 2018Olander and Tyler 2017), and they easily hybridize with each other (Šída 1998, 2000, 2004) or other closely related taxa (Pliszko 2015;Mundell 2016;Pliszko and Jaźwa 2017;Pliszko and Kostrakiewicz-Gierałt 2018). Determination key for Erigeron acris s. l. occurring in Poland is presented below: (

Distribution and habitat
Hypericum majus is a perennial (or annual) species native to North America whose range includes southeastern Canada and northeastern parts of the USA (Robson 1990(Robson , 2015. In Europe it was recognized for the first time in Germany (Tutin et al. 1968;Robson 1990); later, it was observed in several other countries: France (Bouchard 1954;Tutin et al. 1968;Prince and Aniotsbehere 2012), Belarus Trietjakow 2012, 2014;Dubowik et al. 2015) and Italy (Airale et al. 2017). This species has also been introduced in eastern Asia (Robson 1990;Mito and Uesugi 2004). In the area of natural range H. majus grows on fens, marshes, ditches, lake and stream margins and other damp habitats up to 1200 m a.s.l. (Robson 2015). In Europe, the species grows mainly on anthropogenic habitats, such as edges of ponds and ditches (Bouchard 1954;Tutin et al. 1968), in humid depressions in heatherlands (Prince and Aniotsbehere 2012), disturbed peatlands and in peat-bog pools Trietjakow 2012, 2014;Dubowik et al. 2015) and post-mining excavations (Merxmüller and Vollrath 1956;Nezadal 1984). Hypericum majus was probably introduced to Europe unknowingly by American soldiers during World War I (Bouchard 1954;Merxmüller and Vollrath 1956;Westhoff 1971). To Poland, H. majus was probably introduced from Brandenburg with the participation of waterfowl. The invasion of species by this dispersal mode took place in the territory of Belarus (Dubowik, Skuratowicz, and Trietjakow 2012). Hypericum majus has been found in western Poland in several ponds within three active or abandoned fish farms. The whole area of local populations ranges about 2500 m 2 . They are very abundant, with estimated number of tens of thousands of individuals. The floristic composition of H. majus patches has been studied, with relevés using a standard Braun-Blanquet method. The phytosociological documentation of phytocoenosis in the pond in Rościce is presented below. Area of 25 m 2 , cover of the herb layer c: 80%, cover of the moss layer d: 5%, number of species in the relevé: 31. The floristic composition of the phytocoenosis with H. majus corresponds with the phytosociological preferences of this species in western Europe (Bouchard 1954;Prince and Aniotsbehere 2012;Nezadal 1984). In Poland the species develops optimally on periodically exposed pond bottoms. It forms dense phytocoenoses, thus hindering the development of small terophytes from the Isoëto durieui-Juncetea bufonii class. On overgrown and uncultivated ponds, it was also observed in communities of Molinio-Arrhenatheretea, Phragmitetea australis and Scheuchzerio-Caricetea fuscae classes. In comparison to pioneer habitats, the species was there less abundant and grew in small groups.
In France H. majus was recognized as a regional invasive agriophyte (Fried 2010). The species has equal status in western Poland and it is a threat to natural and semi-natural plant communities. From 2009 to 2012, in the fish ponds in Rościce, detailed studies of communities from the class of Isoëto durieui-Juncetea bufonii were conducted (Rosadziński 2016), during which a few individuals of H. majus were observed. Since 2017, the species has significantly enlarged its area, occupying habitats on the bottom of fish ponds; therefore it should be pointed out that it has high invasive potential.

Taxonomic notes
In Poland, the genus Hypericum comprises eight native species: Hypericum maculatum Crantz, Hypericum perforatum L., Hypericum elegans Stephan ex Willd., Hypericum tetrapterum Fr. (section Hypericum), Hypericum humifusum (sect. Oligostema), Hypericum hirsutum L., Hypericum pulchrum L. (sect. Taeniocarpium) and Hypericum montanum (sect. Adenosepalum). In Europe Hypericum majus (A. Gray) Britton (sect. Trigynobrathys) used to be confused with closely related Hypericum canadense (e.g. in France, cf. Jonker 1960). Hypericum majus differs from the H. canadense by broader leaves, larger flowers and usually has more-congested inflorescence (Robson 2015). In order to avoid mistakes in distinguishing the species from native taxa that may occur in similar habitats in Poland (mainly H. tetrapterum and less often H. perforatum), a simplified key is shown below. (

Distribution and habitat
Ludwigia repens is a native species to North and Central America and alien to several continents including Europe. In Europe, occurrence of this species is reported from several countries (DASIE 2018, http://www.europe-aliens.org/speciesFactsheet.do? speciesId=9770#) such as Spain (Rodríguez-Merino, Fernández-Zamudio, and García-Murillo 2017), Germany (GEFD 2018, http://www.kp-buttler.de/flor enliste/), Austria (Fischer, Oswald, and Adler 2008) and Hungary (Lukács et al. 2016). To date, this alien species has not been included in the flora of Slovakia (cf. Medvecká et al. 2012). A population of this species was found in thermal water (temperature > 40 ºC, pH 6.55-7.15 and electrical conductivity~765 μS/ cm) with numerous individuals growing in a thermal pond, and scattered occurrence was detected in a ditch directly connected with the pond, with still and quickly flowing water, respectively. The species was planted in the past and recently successfully spontaneously spread in thermal pond and mentioned ditch with thermal water. In native areas such as North America, L. repens grows in a broad scale of freshwater habitats, shallow, still or flowing, slightly acidic to alkaline waters at elevations up to 1372 m (Les 2018). On the contrary, this alien species was found in thermal waters in Slovakia, as well as in Hungary (Lukács et al. 2016).

Taxonomic notes
Ludwigia repens belongs to the sect. Dantia as a polyploid complex including five species. All species occur in North America in wet habitats. As these species generally lack well-developed preor post-zygotic barriers to hybridization, they commonly form natural hybrid populations (Peng et al. 2005).

Distribution and habitat
Phragmites Adans. (subfam. Arundineae, tribe Moliniae) comprises from 4 to 20 species occurring in wetland habitats of temperate and tropical regions of the world (Clayton 1967;Tzvelev 1976;Clevering and Lissner 1999;Tzvelev 2011). In Belarus Phragmites is represented by two species: widespread native Phragmites australis (Cav.) Trin. ex Steud. and sparsely distributed invasive Phragmites altissimus (Benth.) Mabille (Tretjakov 2013). In October 2012 specimens belonging to Phragmites americanus, species previously not reported from Europe, were collected from Minsk Ringroad. In this locality, P. americanus was probably introduced by accident and occurs in dense stand (5 х 15 m) along the roadside near agricultural fields. Phragmites americanus is native to North America. This species is widespread throughout Canada and most of the United States except of the Southeast (Texas, Florida, North and South Carolina). In North America it grows in tidal and non-tidal wetlands, inland marshes and fens as well as lacustrine and riparian systems (Saltonstall 2002Saltonstall, Peterson, and Soreng. 2004;Saltonstall and Hauber 2007;Swearingen and Saltonstall 2010).

Taxonomic notes
Unfortunately, herbarium specimens of Phragmites are rarely collected, not only because of their large size and late flowering, but also because most botanists used to treat all individuals of Phragmites as belonging to one common species, P. australis. However, recent molecular investigations have shown a very wide range of genotypic variability in this complex (Koppitz 1999;Kühl et al. 1999;Pellegrin and Hauber 1999;Saltonstall 2002Saltonstall , 2003Lambertini et al. 2006). In the temperate zone of North America P. australis s.l. consists of two co-occurring lineages: introduced Eurasian P. australis s.str. and native to North American lineage P. americanus (Haines 2010) (syn. P. australis subsp. americanus ;Saltonstall 2002Saltonstall , 2003. Since these two taxa differ in distribution patterns, vegetative and generative characters, it is more appropriate to treat them as separate species. Phragmites americanus and European populations of P. australis s.l. can be distinguished by many morphological features. Phragmites americanus has longer ligules (1.0-1.7 mm vs. 0.4-0.9 mm in P. australis s.str.), lower glumes (3.0-6.5 mm vs. 2.5-5.0 mm, respectively) and upper glumes (5.5-11.0 mm vs. 4.5-7.5 mm, respectively), lemmas (8.0-13.5 mm vs. 7.5-12.0 mm, respectively). Leaf sheaths of P. americanus become loose with age whereas P. australis has tightly enclosing culm even at later stages. The most easily noticeable characters of P. americanus are smooth, shiny and red-brown to dark red-brown middle and lower stem internodes (similarly to Phragmites japonicus), whereas P. australis s.str. is characterized by ribbed and dull green to tan-coloured middle and lower stem internodes. subsp. oxyptera (Reichenb.) Dethard. Contributors -Valery N. Tikhomirov, Igor I. Shimko

Distribution and habitat
Polygala multicaulis is the Central and Southeast European species. The range of geographic distribution of this species extends from the western part of Russia on the east, throughout the Polish Uplands, up to Denmark via the Lower Rhine Plain, southward via Luxembourg and the Saarland to the area of eastern and southern Switzerland on the west. In the south, extends through southeastern parts of Austria to the borders of Bosnia and Montenegro (Heubl 1984). In Central and Eastern Europe the species is relatively rare; although it occurs in numerous localities in the southern and western regions of Poland, in the north and east parts of the country it is rare (Pawłowski 1958(Pawłowski , 1959Zając and Zając 2001); similarly in Lithuania, where it is known only from the south parts of the country (Kask, Plotniece, and Lekavičius 1996) and in Ukraine where it is known only from a few locations in the Ukrainian Carpathians (Transcarpathian, Ivano-Frankivsk and Lviv provinces) (Tikhomirov 2004(Tikhomirov , 2013b. It grows on grasslands and heaths or in sparse pine forests, mostly on shallow humus or sandy soils with low nutrient content. This species has been recently found in the northwestern part of Belarus and it is considered a new native species to the Belarusian flora.

Taxonomic notes
Polygala vulgaris L. s.l. is one of the most problematic groups of wasteland species in Europe. Within this group, over eight species and intraspecific taxa have been distinguished so far (Heubl 1984;Tikhomirov 2004Tikhomirov , 2013aTikhomirov , 2013bArrigoni 2014). In Belarus this group is represented by three species: Polygala vaillantii Bess. (widespread), P. vulgaris L. s.str. (rare, mainly in the western and central regions of Belarus) and P. multicaulis Tausch (rare, known only from two localities in the northwestern part of the country). Differences between these species are given as a short key for their identification, which includes the main diagnostic features of these species. This key can be used to determine this group in territories surrounding Belarus.

Distribution and habitat
Sagittaria latifolia is an American species frequently occurring in several European countries as an alien (Hussner 2012). Although more distribution data are known from neighbouring countries of Slovakia (Czech Republic, Austria, Ukraine), it has not yet been reported from the territory of Slovakia (cf. Medvecká et al. 2012). In Europe, S. latifolia grows in shallow and eutrophic waters within littoral marshland vegetation; the ecological conditions are similar to native European species Sagittaria sagittifolia L. which prefers slightly wetter habitats (Casper and Krausch 1980). Two of the newly discovered localities had similar ecological conditions: eutrophic, still or slowly flowing, shallow water. In both cases, the individuals of S. latifolia grew in the littoral zone. We suppose that the species was probably planted or dispersed by waterflow in the past in the first locality and than it spontaneously spread throughout the littoral zone. In the second locality, its origin seems to be unknown. In both cases, S. latifolia grows there within typical native marshy vegetation and localities are without direct human impact.

Taxonomic notes
Seven species of the genus Sagittaria are known from the Central European flora, but only one species is native to Slovakia, S. sagittifolia. Sagittaria latifolia is quite similar to S. sagittifolia, but both taxa are relatively well recognizable. Sagittaria sagittifolia has smaller, narrower and more elongated leaves comparing to S. latifolia; both species have white petals, but in the case of S. sagittifolia with a red spot on the petal base (Casper and Krausch 1980).

Distribution and habitat
Rubus ambrosius is a relatively recently described (Trávníček, Oklejewicz, and Zieliński 2005) bramble species form eastern Central Europe, widespread in the Northern Carpathians and on their foothills in Slovakia and Poland, with rather scattered localities in the Czech Republic. Later (Kurtto et al. 2010) it was given also from the eastern part of Germany and northern Hungary, beside an isolated, supposedly non-native occurrence in western Ukraine (near to Lviv). Finally, it was also found at a single locality in Lower Austria (Király and Hohla 2015). Rubus ambrosius is a bramble of submontane-montane regions with beech and mixed oak-hornbeam forests. It prefers forest fringes, woody pastures, and open forests mainly on mesic or semi-dry, neutral or slightly acidic soils. During the recent herbarium revisions in BP, I found several specimens of R. ambrosius in the material collected mainly by Antal Margittai in the 1920s-1930s in the mountain ranges around Mukacevo (at that time Czechoslovakia, today the Transcarpathian region of Ukraine). These specimens reveal that R. ambrosius is native to Ukraine, connected to the already known abundant occurrence from the bordering part of Slovakia in the Northeastern Carpathians.

Taxonomic notes
Rubus ambrosius belongs to the relatively few triploid representatives of Rubus ser. Rubus (Krahulcová, Trávníček, and Šarhanová 2013). It is a majestic bramble, morphologically similar to the widespread tetraploid Rubus sulcatus Vest, but it differs by having deeply furrowed first-year stems (R. sulcatus: stem sides sulcate to almost flat), it has somewhat longer, stronger and denser prickles, petiole usually longer than the lower leaflets (R. sulcatus: petiole usually shorter than the leaflets), leaflets shallowly toothed (teeth up to 2.5 mm deep, for R. sulcatus up to 4 mm), and petals relatively short (up to 13 mm long, for R. sulcatus up to 17 mm)for more identification details, see Trávniček and Zázvorka (2005) and Király and Hohla (2015).

Distribution and habitat
Rubus camptostachys is a widespread European bramble species. The species is most common in Germany, Netherlands, and Denmark, moreover it is also given from Belgium, Luxemburg, southern Sweden, Czech Republic and southern Poland (Kurtto et al. 2010). This species grows mainly in forest margins and thickets, in plant communities of the classes Rhamno-Prunetea, Querco-Fagetea and Artemisietea vulgaris (Holub 1995;Holub and Kučera 2001), however, in southwest Poland it was also observed in pine and oak-pine forests (Maliński 2001). In southeast Poland this species grows most often in sunny and moderately transformed places such as forest margins, overgrowing wastelands and roadsides, together with species of the classes Artemisietea vulgaris, Epilobietea angustifolii, Querco-Fagetea, Molinio-Arrhenatheretea, Agropyretea intermedio-repentis and Stellarietea mediae (Oklejewicz 2006;Wolanin 2015). During the field expedition to western Ukraine in 2017, three localities of R. camptostachys were discovered. We found this species in forest and scrub margins. This plant should be accepted as native to Ukraine.

Distribution and habitat
Rubus perrobustus is a widespread eastern Central European bramble species reported from N Austria, Czech Republic, Slovakia, northern Hungary, southeast Poland, and from somewhat distant localities in southern Germany (Kurtto et al. 2010). Recently, it has also been found in northern Italy (Pagitz 2016). It occurs mostly in submontane and upland regions in thickets, forest margins and clearings in plant communities of the classes Quercetea robori-petreae, Rhamno-Prunetea, Epilobietea angustifolii, Querco-Fagetea, Artemisietea vulgaris and Trifolia-Geranietea sanguinei on mesic to semi-dry and slightly acidic to slightly alkaline soils (Holub 1995;Holub and Kučera 2001;Zieliński 2004;Oklejewicz 2006). In 2017, 11 localities of R. perrobustus were found during the field expedition to western Ukraine. The species grew most often in the pine forest margins and roadsides. Herbarium specimens of this species were also found during the herbarium revision in LW. In view of the species occurrence in the bordering part of Poland (Oklejewicz 2006;Wolanin 2014) and nature character of habitats, this plant should be considered as native to Ukraine.

Distribution and habitat
The native range of Zanthoxylum armatum lies in Tropical Asia and includes Pakistan, India, Nepal, Bhutan, Bangladesh, Laos, Myanmar, Thailand, Vietnam, Indonesia, Philippines, China, Taiwan, Korea and Japan (Hartley 1966;Zhang and Hartley 2008). The former reference includes specimen-based distribution map of the species. There are a few records of the species from Argentina and Italy outside the native range. Arana and Oggero (2009) reported four localities in Córdoba Province of Argentina where Z. armatum was first collected in 1994. Later on, Giorgis and Tecco (2014) supposed that the Argentinean records are still the only reports of Z. armatum naturalization in the world, but that was not perfectly correct.
In 2003, Z. armatum was photographed by G. Donzelli near Blevio in Lombardy, Italy and consequently collected here by G. Galasso in 2011-12 (Galasso andBanfi 2012). Later on, other episodes of naturalization have been recorded in Italy (Montagnani et al. 2016).
Following Zhang and Hartley (2008), Z. armatum is a deciduous plant in its native range being a shrub, woody climber, or a tree to 5 m tall. Zernov (2013) mentioned that in cultivation it is a semi-evergreen small tree 2-4 m tall flowering in June. According to my observations confirmed by a specimen, Z. armatum was in bloom in late April in Khosta with most leaves on the plant being overwintered. Several individuals were growing along the road on hardwood forest margin on the west-facing slope of the hill. The forest is dominated by mature Carpinus betulus, Fraxinus excelsior L., and some Acer campestre L. Abundant Hedera helix L. covers ground, trunks and a shrub layer composed from Ligustrum vulgare L., Ficus carica L., and Cornus spp. The road is ca. 5 m wide, therefore the habitat is in shade all day long. Most probably, the seeds were dispersed by birds from nearby hotels or estates.
Habitats of Z. armatum in Lombardy are similar to those I have recorded in Sochi. They include mixed deciduous forests and margins of forest paths at the altitude of ca. 500 m a.s.l. (Galasso and Banfi 2012).

Taxonomic notes
Being a plant with a wide native range in Tropical Asia and a long history of cultivation in botanical gardens, Zanthoxylum armatum had accumulated a number of synonyms. Galasso and Banfi (2012) (Kitamura and Murata 1972;Ohba 1999). All these names were synonymized by Zhang and Hartley (2008) following earlier revision by Hartley (1966). I follow this concept in the absence of other revisions. In fact, Asian Zanthoxylum L. (ca. 50 species) are insufficiently studied and need complete revision in the molecular era. At the moment, no infrageneric classifications were introduced for Asian species, although some sectional names are available since the nineteenth century. Appelhans et al. (2014) published the only available molecular phylogenetic analysis of Zanthoxylum with a special reference to Hawaiian species based on 37 sampled species, including 20 taxa from Asia. In the tree based on ITS and one plastid intergenic spacer (trnL-trnF), a single accession of Z. armatum showed a basal sister position to a monophyletic group of three lineages, namely (1

Notes on contributors
Oyuntsetseg Batlai's main research field are taxonomy and chorology of native flora of Mongolia, taxonomy and phylogeny of vascular plants (especially Brassicaceae). The current projects are "Diversity Survey on the Mongolian Vascular Flora". The author's contributions are field and laboratory research and preparation of selected parts of the manuscript.
Kateřina Bubíková is a researcher at the Water Research Institute in Bratislava. The author's contributions comprised field work and preparation of selected parts of the manuscript. Hyeok Jae Choi main research are systematics (taxonomy), evolutionary biology and ecology of the genus Allium. The current projects are "Diversity Survey on the Mongolian Vascular Flora", "Monograph for the Genus Allium" and "Taxonomy and Systematics of the Genus Sagittaria". The author conducted field research in Mongolia and his contributions are field and laboratory research and preparation of selected parts of the manuscript. Polina D. Gudkova has worked on the systematic and evolution of feather grasses since 2007. She has conducted field studies in Russia, Kazakhstan, Kyrgyzstan, Tajikistan and Nepal, focusing on their diversity, ecology, phylogenetics, systematics and biogeography. The author's contributions are revision of herbarium materials and the preparation of selected part of the manuscript.
Vitaliy Honcharenko is currently working on taxonomy and chorology of the genus Rubus in Ukraine and Belarus as well as on adventive species in the west of Ukraine. The author's contributions comprised field studies and preparation of selected parts of the manuscript.
Richard Hrivnák is a senior researcher at the Institute of Botany, Plant Science and Biodiversity Center, Slovak Academy of Sciences in Bratislava. The author's contributions comprised field work and preparation of selected parts of the manuscript. Arkadiusz Nowak has worked on the syntaxonomy of Middle Asia vegetation with special focus on forest, scree, rock, segetal and riparian vegetation. He has conducted many field studies in Tajikistan, Kyrgyzstan, and Uzbekistan. The author's contributions are field studies and preparation of selected parts of the manuscript.
Krzysztof Oklejewicz's ( †1962-2018) main research interests were plant chorology and taxonomy of the genus Rubus, Crataegus and Taraxacum. The author's contributions comprised field studies and preparation of selected parts of the manuscript.
Marina Olonova has worked on the systematic and evolution of bluegrasses for more than 40 years. She has conducted many field studies in Siberia, China and Tajikistan, focusing on their diversity, systematics and biogeography. The author's contributions are analyses of data and preparation of selected parts of the manuscript.
Helena Oťaheľová is an emeritus senior researcher at the Institute of Botany, Plant Science and Biodiversity Center, Slovak Academy of Sciences in Bratislava. The author's contributions comprised field work and preparation of selected parts of the manuscript. Igor I. Shimko works as senior lecturer at the Fodder Production Department in Viciebsk Academy of Veterinary Medicine. His scientific interests covers such problems as distribution features of vascular plants in Viciebsk region, ecology and biology of rare and protected species in Belarus, flora of protected areas, perennial fodder representatives of pea family in agriculture. The author's contributions are field and laboratory research and preparation of selected part of the manuscript.
Baasanmunkh Shukherdorj is currently a PhD student at the Department of Microbiology, Changwon National University in Korea. The author does research in "Diversity Survey on the Mongolian Vascular Flora". The author conducted field research in Mongolia.
Gábor Sramkó is a senior researcher interested in evolutionary history of plants with a special focus on orchids and steppe plants. The author's contributions are field studies and preparation of selected parts of the manuscript.
Ana Terlević is a biology graduate from the University of Zagreb (Croatia) whose interests cover floristics and ecology of native and non-native vascular plants of Central and Southern Europe. She spent three months as a trainee at the Institute of Botany of Jagiellonian University where she took part in research related to alien invasive plants in Poland. The author revised herbarium materials and cowrote selected parts of the manuscript. Anna Wróbel is an MSc student of biology at Jagiellonian University, Kraków, Poland. She carries out research about taxonomy and phylogeny of the genus Puccinellia and Eragrostis, and is also interested in evolution of plants occurring in the mountains. The author was involved in field studies and co-wrote selected part of the manuscript.
Kunli Xiang is a PhD student of the Institute of Botany, Chinese Academy of Sciences. She is interested in taxonomy and phylogeny of angiosperms (especially in Ranunculaceae). The author's contribution included preparation of selected parts of the manuscript.
Elena Yu. Zykova is a researcher at Laboratory Herbarium (NS) of the Central Siberian Botanical Garden at Novosibirsk. Her main research interests are study of the alien flora of Southern Siberia. The author's contributions are field and laboratory research and preparation of selected parts of the manuscript.