Casual Alien Research Articles

Checklist of Ornamental Trees, Shrubs, and Succulents of Apulia (Southern Italy).

In this study we focused on the need to fill a knowledge gap among Italian botanical studies namely that of ornamental species census. In particular, we addressed one of the regions in southern Italy with less knowledge in the field of such studies and with an obvious presence of non-native species. A widespread census of the Apulian territory was carried out between 2021 and 2024 in both urban and suburban areas including street trees, parks, and private and historic gardens. The inventory of ornamental trees, shrubs, and succulents of Apulia (southern Italy) was carried out in six provinces, i.e., Bari, Barletta-Andria-Trani, Brindisi, Foggia, Lecce, and Taranto. The checklist comprises 287 taxa (including 265 species, 6 varieties, 5 subspecies, and 11 forms) included in 179 genera belonging to 78 families. We evaluated the number of taxa per families and genera, the presence of each taxa in the provinces of Apulia, the number of taxa per occurrence status, growth forms, geographical origin, and the number of native and alien taxa and also the artificial hybrids. Remarks of the most significant taxa and evaluation of geographical distribution in Italy were also taken into consideration. A large number of surveyed taxa (51.74%) are comprised in the list reported in the recent study on allochthonous vascular flora in Italy with a marked prevalence of Neophyte Casual Alien and Neophyte Naturalized Alien species.

Additional data on the ongoing naturalization of the non-native woody plant Duranta erecta ( Verbenaceae) in Sicily, Italy

We recorded the occurrence of Duranta erecta L. in the Aeolian Islands (Sicily, Italy), where it currently behaves as a casual alien. At the global scale, however, this woody species has shown highly invasive behaviour in different island ecosystems. On the basis of this evidence, we have investigated which ecological and biological traits may have allowed its establishment and spread, and could trigger its further expansion in the Aeolian Islands in the near future. Several factors seem to have favoured its success on a global scale, such as the wide edaphic and climatic range, the tolerance to anthropogenic disturbance, and the production of toxic metabolites that protect it from herbivore browsing and from competition with other plants. The study of the organisms that perform pollination and seed dispersal is probably the key to understanding the local naturalization of this plant, introduced about three centuries ago in Europe and the Mediterranean, here discussed in detail for the first time.

A second update to the checklist of the vascular flora alien to Italy

Critical and updated alien species inventories are crucial to properly manage and contrast biological invasions. After 6 years, a second update to the inventory of the vascular flora alien to Italy is presented. It provides details on the occurrence at administrative regional level and, for the first time, floristic data for San Marino. The checklist includes 1782 taxa (1673 species, 28 subspecies, 69 hybrids and 12 cultivar groups not attributable to a specific binomial), distributed in 786 genera and 159 families; 2 taxa are lycophytes, 13 ferns and fern allies, 37 gymnosperms and 1730 angiosperms. Among these, 154 taxa are archaeophytes and 1628 neophytes. The alien taxa currently established in Italy are 899 (649 naturalized and 250 invasive), while 796 taxa are casual aliens, 1 is not assessed, 38 have not been confirmed in recent times, 4 are considered extinct or possibly extinct in the country, 40 are doubtfully occurring in Italy, 4 are of unknown regional distribution and 110 are reported by mistake and to be excluded at national level. This checklist allows to establish an up-to-date number (10,023) of taxa currently constituting the whole (either native or alien) Italian flora.

Alien Plants of Kyrgyzstan: The First Complete Inventory, Distributions and Main Patterns.

The first inventory of casual and naturalised alien plants of Kyrgyzstan is based on an overview of published data, which were re-assessed and re-evaluated using modern standards. Altogether, 151 alien species were registered in the country, of which nearly 40% became naturalised. The total number of alien plant species and the proportion of casual aliens are relatively low due to the harsh climatic conditions (high aridity and continentality) and predominantly high elevations. The highest number of alien plant species in Kyrgyzstan originated from the Mediterranean, which can be explained by some common climatic features between this area and Central Asia, but half of the ten most harmful aliens originated from the Americas. The intensity of plant invasions was the greatest during the period of the Russian Empire and the USSR, and this rapid accumulation of alien plants continues in independent Kyrgyzstan. The uneven distribution of alien plants in Kyrgyzstan is explained by different elevations and climatic conditions across its regions, as well as by the concentration of agricultural activities and human population along warm lowland depressions. More research is required to uncover pathways and particular times of introduction and to produce detailed distribution maps.

Alien Species of Vascular Plants in the Flora of Prioksko-Terrasny Biosphere Reserve

The paper presents data on alien species of vascular plants in the Prioksko-Terrasny Biosphere Reserve. In total 96 species are classified as alien, which is 10,6% of the total floristic diversity. This proportion is small and reflects a low disturbance and relative stability of indigenous phytocenoses. The appearance of a new 43 alien species for the flora of the reserve was noted. The characteristics of the current state of populations of alien species, location and prospects for further development, are given. Almost all alien species registered by us (with the exception of Oxalis stricta, Torilis japonica, Conyza canadensis) to one degree or another are the result of introduction activities. Depending on the degree of naturalization and potential danger to the ecosystem, alien species are divided into 5 categories: Status 0 – cultivated (unnaturalized) (32 species); Status 1 – alien non-naturalizing plants (11 species); Status 2 – casual alien plants (2 species); Status 3 – naturalized plants (45 species); Status 4 – invasive species-transformers (6 species). Areas occupied by Cornus alba and Caragana arborescens have been measured to further estimate population growth by comparing with a similar measurement after several years. Extermination of small pioneer Heracleum sosnowskyi population is recommended.

Dittrichia graveolens (Asteraceae), rapidly spreading along European highways, recorded in Lithuania

For a long time, railways were the main pathway for the accidental introduction of alien plant species, but now highways and other roads are becoming increasingly important in this process. Considering that Dittrichia graveolens is spreading rapidly along highways in Central Europe and neighbouring Poland, a targeted search was conducted in Lithuania in 2023. Dittrichia graveolens was recorded at two sites along the Kalvarija–Kaunas highway (Kazlų Rūda district, in the environs of Pentupiai, and Kaunas city, in the environs of Jonučiai). At both sites, the species occupied relatively compact stands consisting of several hundred individuals, suggesting that the stands were formed from locally matured seeds. The mean number of flowers per capitulum in Lithuania in 2023 was 20.5 ± 4.9, and the realised fecundity was 89.7% of the potential fecundity. It is presumed that the seeds of Dittrichia graveolens were accidentally introduced into Lithuania by trucks, probably attached to tyres. Currently, this species is classified as a casual alien, but its naturalisation is expected. The study revealed that the first record of Dittrichia graveolens in Poland was not in 2013, as previously reported, but more than 20 years earlier, in 1990, near Kraków, at the slag deposit site of the Nowa Huta Steelworks.

Dittrichia graveolens (Asteraceae), rapidly spreading along European highways, recorded in Lithuania

For a long time, railways were the main pathway for the accidental introduction of alien plant species, but now highways and other roads are becoming increasingly important in this process. Considering that Dittrichia graveolens is spreading rapidly along highways in Central Europe and neighbouring Poland, a targeted search was conducted in Lithuania in 2023. Dittrichia graveolens was recorded at two sites along the Kalvarija–Kaunas highway (Kazlų Rūda district, in the environs of Pentupiai, and Kaunas city, in the environs of Jonučiai). At both sites, the species occupied relatively compact stands consisting of several hundred individuals, suggesting that the stands were formed from locally matured seeds. The mean number of flowers per capitulum in Lithuania in 2023 was 20.5 ± 4.9, and the realised fecundity was 89.7% of the potential fecundity. It is presumed that the seeds of Dittrichia graveolens were accidentally introduced into Lithuania by trucks, probably attached to tyres. Currently, this species is classified as a casual alien, but its naturalisation is expected. The study revealed that the first record of Dittrichia graveolens in Poland was not in 2013, as previously reported, but more than 20 years earlier, in 1990, near Kraków, at the slag deposit site of the Nowa Huta Steelworks.

Vascular Plant Species Inventory of Mexico's Revillagigedo National Park: Awareness of Alien Invaders as a Sine Qua Non Prerequisite for Island Conservation.

The Revillagigedo Archipelago, located in the Eastern Pacific Ocean, stands out for its unique biological richness and endemism. These islands remained uninhabited until the second half of the twentieth century, allowing a better conservation status than on other oceanic islands. However, the continuous introduction of potentially invasive alien plant species, and the lack of adequate control or eradication actions, jeopardize the conservation and restoration of these islands' fragile ecosystems. We present the most complete vascular plant species inventory and an updated list of alien plant species of the Revillagigedo Archipelago, which was compiled through an extensive review of national and international plant collections and other sources. Our 272 species list includes 106 alien plant species (39.3%; 104 in Socorro, and 16 in Clarion): 67 (24.8%) are naturalized, 14 (5.2%) are casual aliens, and 25 (9.3%) subsist under cultivation. The documented alien species belong to 73 families. Annual and perennial herbs are the prevailing life forms in the alien flora, while naturalized species are primarily native to North America. The number of introduced species has increased significantly since the islands became inhabited. Many of the recently introduced species pose a major invasion risk like on other islands of the world.

An updated inventory of the vascular flora of the Cerbaie hills (Tuscany, Italy)

We present an updated list of the vascular flora occurring in the Cerbaie hills (Tuscany), a site of high naturalistic interest. The list is based on a literature survey and on field studies carried out in the years 2010–2022. The Cerbaie hills host a flora of 1,107 specific and subspecific taxa (including 100 naturalized aliens), 32 casual aliens and 10 hybrid taxa. Two taxa are new for Tuscany: Carex oedipostyla and Thalictrum simplex subsp. galioides; 330 taxa are new for the study area. Concerning old records, 344 have been confirmed, while 47 were not confirmed, albeit considered reliable. Moreover, we considered three taxa as locally extinct, 19 as doubtfully occurring, and three as wrongly reported. Despite the low elevation of the study area, life forms and chorotypes show marked Eurosiberian affinities, in agreement with the temperate and continental climate.

Escape from the garden: spreading, effects and traits of a new risky invasive ornamental plant (Gaillardia aristata Pursh)

Ornamental plants constitute a major source of invasive species.Gaillardia aristata(great blanketflower) is planted worldwide and its escape has been reported in several European countries without ecological impact assessment on the invasive potential. As there is a markedly spreading population with invasive behaviour in Hungary, we aimed to reveal the distribution, impacts and traits ofG. aristata. We gathered occurrence data outside the gardens in Hungary, based on literature, unpublished observations by experts and our own records. We investigated the impacts of an extended population, where the species invaded sandy old-fields within a 25 km2area. Here, we compared the species richness, diversity, community composition and height of invaded and uninvaded vegetation. Furthermore, we evaluated the traits potentially associated with the invasiveness ofG. aristatain comparison with other herbaceous invasive species in the region. We found thatG. aristataoccurred mostly by casual escapes, but naturalised and invasive populations were also detected in considerable numbers.G. aristatausually appeared close to gardens and ruderal habitats, but also in semi-natural and natural grasslands and tended to spread better in sandy soils. We found lower plant species richness and Shannon diversity in the invaded sites and the invasion ofG. aristatasignificantly influenced the composition of the plant community. The trait analyses revealed that the invasive potential ofG. aristatais backed by a wide germination niche breadth, extremely long flowering period, small shoot-root ratio (large absorption and gripping surface), large seeds (longer persistence) and dispersal by epizoochory of grazing livestock (mostly by sheep), probably helping the species’ survival and spreading in the disturbed, species-poor, sandy, open habitats. These functional traits, as well as the ornamental utilisation, may act together with the aridisation of the climate and the changing land-use practices (e.g. abandoned, disturbed sites) in the success ofG. aristata. We raise awareness of the rapid transition ofG. aristatafrom ornamental plant to casual alien and then to invasive species in certain environmental conditions (i.e. sandy soils, species-poor communities, human disturbances), although it seems to be not a strong ecosystem transformer so far. Nonetheless, banning it from seed mixtures, developing eradication strategy and long-term monitoring of this species would be important to halt its spreading in time.

Rudbeckia triloba L. (Asteraceae) – new (?) alien species in the flora of Croatia

During the summer of 2022 Rudbeckia triloba L. was recorded outside cultivation at four localities in the inland part of Croatia (Korana Selo, Vukova Gorica, Vugrovec and Slivonja Jarek) growing in anthropogenic habitats. This species, native to North America, was introduced to Europe as an ornamental and in several European countries is spreading mostly as garden escapee. The time of introduction into Croatia is not known. It can be considered a casual alien or a garden escapee ephemerophyte with an as yet unknown invasive potential.

Remarks on the exotic flora of Capo Mortola (Ventimiglia, northern Italy) and its changes over time

In this study, we compared current data and data of the census made in the 1990s related to the vascular flora of Capo Mortola (Ventimiglia, Italy), considering 270 taxa not dependent on crop management. The current status reported 198 alien species: 5 invasive, 65 naturalized 75 casual, 38 occurring as casual in human-dominated systems, but without direct intervention by humans and not close to parent plant, 15 occurring as casual alien, but still with some uncertainties for a definitive classification, and plus 3 cryptogenic and 1 eradicated (extinct) taxa, while in 1996 were 229 species: 87 naturalized and 142 adventitious (casual). Of these, 40 taxa show an increasing trend and 41 a decreasing or disappearing trend. If we consider the wild areas of Capo Mortola, 10 taxa are new to the Italian flora (7 casual and 3 naturalized) while 13 are new to the Ligurian flora only (all casual). If we also consider the neglected areas of the Botanical Gardens, 18 new casual species for the Italian flora and 10 for the Ligurian one would be added. In addition, 9 status changes are proposed on a national scale and 17 on a regional scale. An in-depth analysis was conducted on the presence and the local history of a subset of 34 exotic plants, 11 of which are new or have a new status for the Italian flora.

A new classification of C4- Atriplex species in Russia, with the first alien record of Atriplexflabellum (Chenopodiaceae, Amaranthaceae) from North Siberia.

For a long time, the systematics of Atriplex was based solely on morphological characters and leaf anatomy. The latest worldwide phylogenetic study of Atriplex significantly improved our knowledge about the relationships within the genus, but a new classification has not been put forward thus far. Here we re-evaluate the taxonomy of C4-species of Atriplex that are native to Russia. Seven species are classified into two sections, A.sect.Obione (incl. A.sect.Sclerocalymma, syn. nov.) (A.altaica, A.centralasiatica, A.rosea, A.sibirica, and A.sphaeromorpha), and A.sect.Obionopsis (incl. A.sect.Psammophila, syn. nov.) (A.fominii and A.tatarica). Although the majority of Eurasian C4-species have similar morphology, leafy inflorescence is a typical character for A.sect.Obione. The members of A.sect.Obionopsis are characterised mostly by aphyllous inflorescences, but some species (A.laciniata, A.pratovii, and A.tornabenei) have leafy inflorescences. Geographically, almost all members of A.sect.Obione are confined to Central Asia, although A.rosea is a typical Mediterranean element and A.argentea occurs in North America. The representatives of A.sect.Obionopsis are distributed mostly in the Mediterranean and the Irano-Turanian floristic region. The alien status of A.rosea, A.sibirica and A.tatarica is discussed. Atriplexflabellum, a desert species from the Irano-Turanian region, is reported for the first time from Russia (Yamalo-Nenets Autonomous District, North Siberia) as a casual alien. This species occupies a phylogenetic position distant from both aforementioned sections. An identification key to all C4-species of the genus growing in Russia is given, and a sectional checklist with updated nomenclature and revised synonymy is provided.

The first checklist of alien vascular plants of Kyrgyzstan, with new records and critical evaluation of earlier data. Contribution 2.

BackgroundWe continue the inventory of alien vascular plants of Kyrgyzstan, with emphasis on the time and pathways of introduction of the species and their current status in the territory. Each taxon is discussed in the context of plant invasions in Central Asia. This work is a further development of the preliminary checklist of alien plants of Kyrgyzstan, which was compiled for the Global Register of Introduced and Invasive Species in 2018.New informationThis contribution includes all alien species of Kyrgyzstan belonging to Solanaceae and Asphodelaceae and one species of Asteraceae. Physalisphiladelphicus (syn. P.ixocarpa) is reported for the first time from Central Asia, as new to Kazakhstan, Kyrgyzstan and Uzbekistan, thus marking a recent invasion with a variety of imported grain and seed material. The old records of P.ixocarpa from Uzbekistan are based on misidentified specimens of P.angulata. Physalisangulata is an old cotton immigrant in Central Asia, whose invasion started in the 1920s; it is excluded from the alien flora of Kyrgyzstan as registered in error on the basis of cultivated plants. Alkekengiofficinarum is an archaeophyte of the Neolithic period in Central Asia, formerly used for food, now strongly declining and largely casual in Kyrgyzstan. The only historical record of Physalisviscosa from Uzbekistan was based on a technical error and belongs to A.officinarum. Daturastramonium and Hyoscyamusniger were introduced as medicinal plants during the period of the Arabic invasion of Central Asia, by the 11th century. Daturainnoxia is a newly recorded casual alien, recently escaped from ornamental cultivation. Nicandraphysalodes is a casual alien, which was cultivated by Russian colonists in the early 20th century for culinary use and is currently used in ornamental cultivation. Hemerocallisfulva was a remnant of historical cultivation in the former Khanate of Buxoro, and its formerly established colonies are presumably extinct in the wild. Bidensfrondosa was seemingly introduced with contaminated forage and seed of American origin during the late Soviet period and started to spread in the period of independence; its invasion in the former USSR is analysed.

On the occurrence and naturalization of Amaranthus hypochondriacus (Amaranthaceae) in some European countries, with notes on its climatic features

Abstract The occurrence and invasion status of Amaranthus hypochondriacus in Belarus, Estonia, Italy, the Netherlands, and the North Caucasus were discussed. For Italy, we change the status from casual to naturalized based on living populations which are able to sustain themselves for 5 and over 20 years. Concerning the other countries, we clarified the invasion status of the species (inconsistently reported in literature) indicating it as a casual alien in Belarus, Estonia, and the North Caucasus and naturalized in the Netherlands. Climatic data of the European stations in which Amaranthus hypochondriacus was found were compared with those referring to the native distribution area (Mexico and southeastern regions of the US). The occurrence of the species in Europe appears to be facilitated by the temperate climate (Dutch and Italian localities), which also characterizes the native distribution area (N-America). The occurrence of the species in Estonia, the Netherlands, and the North Caucasus is interesting. In fact, although the types of climates (“Cold, Dfb” and “Temperate, Cfb”) occur in America (northeastern US and central Mexico), there are some differences in precipitation and temperature values, i.e. lower mean precipitation [644.1 mm (Estonia) vs. 1119 mm (N-America); climate Dfb] and lower mean temperature [9.7–11.1 °C (Netherlands and North Caucasus) vs. 15.3 °C (Mexico); climate Cfb].

Composition, introduction history and invasion status of alien flora in Dachigam National Park of Kashmir Himalaya

Protected areas (PAs) hold pivotal importance as repositories of biodiversity, especially for some flagship species of high conservation priority. The growing threat of biological invasions in PAs defies the general perception that these areas are rather immune to invasions. Given the paucity of information on the status of biological invasions in the Himalayan PAs, here we developed a well-annotated inventory of alien flora in Dachigam National Park (DNP) through intensive field surveys for the period of 2 years (2019–2021) and recorded 56 alien species with majority (50 species) as neophytes and 6 archaeophyte species belonging to 48 genera and 26 families. Of these alien plant species, 43% species are naturalized, 29% invasive, 20% cultivated, 4% casual aliens and 5% either cultivated or casual. Amongst different natural habitat types investigated in DNP, the grasslands and riparian habitats were found to be most prone to invasive species. These invasions are attributed to myriad of anthropogenic pressure and growing human-footprint in and outside the DNP. The checklist of alien plant species containing useful information on invasion status, growth form, nativity, mode and purpose of introduction is an important tool with the managers of the PA for keen monitoring and effective management of invasive species in the DNP. In view of UN Decade for Ecosystem Restoration (2021–30), the PA managers can use this checklist to plan their strategies well for restoration of invaded habitats and preventing further invasions in tune with the CBD Programme of Work on Protected Areas. So we recommend preparing such checklists for other PAs as well in view of importance this baseline information to deal with invasion-driven changes.

A review of the subtribe Centaureinae (Asteraceae, Cardueae) in Lithuania with information on new alien species

The study’s objective was to overview all Centaureinae species recorded in Lithuania, evaluate the distribution and population state of the newly discovered four alien species and provide information on the residence status, distribution and habitats occupied by all species of the subtribe. The subtribe Centaureinae in Lithuania is now represented by five genera: Centaurea, Leuzea, Psephellus, Serratula and Zoegea. The largest genus in the flora of the country is Centaurea, which includes four native and six alien species. The genus Serratula is represented by one native species, while the genera Leuzea, Psephellus and Zoegea each have one alien species. Tree alien species (an archaeophyte, Centaurea cyanus, and neophytes Centaurea montana and Psephellus dealbatus) are naturalised aliens, whereas Centaurea cheiranthifolia, Centaurea diffusa, Centaurea iberica, Centaurea macrocephala, Leuzea repens and Zoegea crinita are casual aliens. Five species of the subtribe Centaureinae (Centaurea jacea, Centaurea phrygia, Centaurea scabiosa, Centaurea stoebe and Serratula tinctoria) are native to Lithuania. Maps of the distribution of newly discovered alien species in Lithuania are presented.

Italian Vascular Flora: New Findings, Updates and Exploration of Floristic Similarities between Regions

The tradition of floristic studies in Italy has made it possible to obtain a good knowledge of plant diversity both on a national and regional scale. However, the lack of knowledge for some areas, advances in plant systematics and human activities related to globalization, highlight the need for further studies aimed at improving floristic knowledge. In this paper, based on fieldwork and herbaria and literature surveys, we update the knowledge on the Italian vascular flora and analyze the floristic similarities between the administrative regions. Four taxa, all exotic, were recorded for the first time in Italy and Europe. In detail, Elaeodendron croceum, Kalanchoë blossfeldiana, and Sedum spathulifolium var. spathulifolium were found as casual aliens, while Oxalis brasiliensis was reported as historical record based on some herbarium specimens. Furthermore, Kalanchoë laxiflora was confirmed as a casual alien species for Italy and Europe. Status changes for some taxa were proposed at both national and regional levels, as well as many taxa were reported as new or confirmed at the regional level. Currently the Italian vascular flora comprises 9150 taxa of which 7547 are native (of which 1598 are Italian endemics) and 1603 are exotic at the national level. The multivariate analysis of updated floristic data on a regional scale showed a clear distribution along the latitudinal gradient, in accordance with the natural geographical location of the regions in Italy. This pattern of plants distribution was not affected by the introduction of alien species. Despite some taxonomic and methodological issues which are still open, the data obtained confirm the important role of floristic investigations in the field and in herbaria, as well as the collaborative approach among botanists, in order to improve the knowledge of the Italian and European vascular flora.

The alien vascular flora of Stromboli and Vulcano (Aeolian Islands, Italy)

The updated censuses of the alien flora of the islands of Stromboli and Vulcano, Aeolian Islands in the Central Tyrrhenian Sea, are presented here. They currently consist of 40 and 57 specific and subspecific taxa respectively. As many as 16 and 18 taxa respectively are new in comparison with the last censuses in 2016. Mesembryanthemum × vascosilvae, commonly cultivated in both islands, is reported for the first time as naturalized alien to Italy. Passiflora incarnata from Stromboli and Pelargonium graveolens from Vulcano are reported for the first time as casual aliens to Sicily. The evolution over time of these florulas, as inferred from the main floristic works published on these islands, is commented on. Biology, ecology and possible causes of settlement of these plants are discussed briefly.

The first checklist of alien vascular plants of Kyrgyzstan, with new records and critical evaluation of earlier data. Contribution 1.

BackgroundNational checklists of alien plants and detailed databases of non-native plant occurrences are required to study and control regional and global plant invasions. No country in Central Asia has a national checklist of alien plants. A recent inventory counted 183 alien plant species in Kyrgyzstan, including archaeophytes and neophytes, established and casual. This preliminary checklist, which was developed for the Global Register of Introduced and Invasive Species in 2018, served as a starting point for the present study.New informationA complete inventory of Xanthium in Kyrgyzstan has revealed that three alien species are resident in the country. Their correct nomenclature is X.orientale (syn. X.albinum, X.californicum, X.sibiricum auct.; invasive neophyle of the period of extensive grain import to the USSR after the Second World War), X.spinosum (invasive neophyte of the period of the Second World War, which arrived as a contaminant on the relocated livestock) and X.strumarium (syn. X.chinense, X.sibiricum; archaeophyte of the Neolithic period, introduced with wheat cultivation, which had lost its invasive status and appeared on the verge of extinction when its pool was no longer renewed by contaminated grain). A history of introduction to Central Asia is uncovered for all the species of Xanthium. A further spread is documented for Buniasorientalis, with a new record extending its distribution to the Eastern Tian-Shan; a complex history of its introduction to Europe and Central Asia is inferred from the archaeological data and its recent dispersal, and the pathways of its introduction to Kyrgyzstan are established. Erigeronannuus s.str. is reported as new to Kyrgyzstan and Uzbekistan, and E.lilacinus as new to Kyrgyzstan, Uzbekistan, Kazakhstan, Nepal and Tajikistan (it was previously recorded as E.annuus s.l. from the three latter countries, in which the presence of E.annuus s.str. is not confirmed). These closely related species differ in their pathways of introduction and invasion status: E.annuus s.str. is an invasive established alien which was imported as a contaminant of forage, whereas E.lilacinus is mostly a casual (locally persisting) alien introduced with contaminated seed of ornamental plants or nursery material, and also intentionally introduced and locally established in the Botanical Garden in Bishkek. Bidenstinctoria (syn. Coreopsistinctoria) is newly recorded as a casual alien from a single locality in Kyrgyzstan; this species name is validly published here in conformity with the phylogeny of Coreopsideae.Point maps of species distributions in Kyrgyzstan are provided on the basis of a complete inventory of the literature data, herbarium specimens and documented observations, and our recent fieldwork. The maps are documented with a dataset of herbarium specimens and observations. Period and pathways of introduction, vectors of dispersal, current and historical invasion status, evidence of impact and distributional trend are established or inferred for each species. Each species is discussed in the context of plant invasions in Central Asia as a whole.These species accounts are part of the national database of alien plants which aims at producing a comprehensive overview and analysis of plant invasions in Kyrgyzstan.