Cultigenic.

Although some earlier studies indicated that the species is native to Eastern Europe (Candolle 1908, Al-Shehbaz 1988), its natural populations are lacking (Kotov 1979, Ball 1993, Sampliner and Miller 2009).

Europe, temperate and northern Asia, temperate and northern North America.

The species may persist in places of its original cultivation for an uncertainly long time (Wedelsbäck Bladh et al. 2014). Its secondary distribution seems to be exclusively linked with cultivation places. Further dispersal occurs with soil transportation in populated places and along roads and with water currents along rivers.

In Europe, Armoracia rusticana is very common in the territories of its former cultivation (Jalas and Suominen 1994). In comprehensive recording activities, as for example, in Lithuania (Gudžinskas and Rašomavičius 2023), the species may be found commonly naturalised and persisting in the territory, with an active secondary dispersal into nature with garden waste and subsequent soil disturbance by road construction and maintenance.

In Northern Asia, the species has been registered as alien in nearly all floristic regions (Chepinoga et al. 2024), whereas its occurrence in China is limited to five provinces (Zhou et al. 2001), in which the species was first found only at the beginning of the 20^th century (Xu et al. 2012).

Up to the mid-20^th century, most of the sources indicated that Armoracia rusticana is a cultivated plant that becomes ruderal at the places of its cultivation. In Siberia, the species was cultivated at least from the second half of the 19^th century (Ankipovich and Ebel 2016), apparently introduced in the course of extensive colonisation from the central and then southern European parts of the Russian Empire (Vinogradova 2016) and considered restricted to anthropogenic landscapes by the first quarter of the 20^th century (Krylov 1931). In the 21^st century, numerous regional reports have noted the dispersal and naturalisation of the species into natural habitats along watercourses (e.g. Zykova (2023)). Currently, the species is listed among invasive vascular plants in Siberia (Ankipovich and Ebel 2016).

Kazakhstan, Kyrgyzstan, Tajikistan, Uzbekistan. Available subspontaneous records are shown in Fig. 1.

Figure 1.  

Subspontaneous records of Armoracia rusticana in Central Asia, according to herbarium specimens and documented observations (iNaturalist 2024, Plantarium 2024).

In Kazakhstan, Armoracia rusticana was cultivated in private vegetable gardens by Russian colonists, who brought this highly popular condiment from Central Russia (Gubanov et al. 1976). According to herbarium records, the species was known in cultivation in Almaty by 1886 and found naturalised in native habitats along rivers in the north-western regions in the 1920s and in the north-eastern regions by 1960 (Vasilieva 1961), where it was certainly present for a significant period of time before being recorded. Further reports of alien occurrence are known from the northern regions (Perezhogin et al. 2023). Recent records (Fig. 2) indicate its extensive spread along rivers around large towns of the north-east, for example, Semei (formerly Semipalatinsk), Öskemen (formerly Ust-Kamenogorsk) (Plantarium 2024) and Astana (iNaturalist 2024). Numerous recent records from the southern regions (iNaturalist 2024) are from mostly ruderal populations and belong to the dispersal from Soviet-time garden cultivation.

Figure 2.  

Naturalised stands of Armoracia rusticana along a bridge across the Ishim River, Astana City (photo by Yu. Morozova, 1 June 2023). Source: https://www.inaturalist.org/observations/166388104 (Plantarium 2024).

In Uzbekistan, the species has been known from cultivation (Botschantzev and Vvedensky 1955). Currently, it remains in use not only in larger towns, but also in Uzbek villages in the mountainous regions (Kosimov et al. 2023). So far, its running wild has not been recorded in the country (Sennikov et al. 2020).

In Kyrgyzstan, Nikitina (1955) considered the species as present only in cultivation. Its alien occurrence has been reported by Deza (1989) without any further particulars and taken into account in the recent compilations (Lazkov and Sultanova 2011, Lazkov and Sultanova 2014, Sennikov and Lazkov 2024a).

The latest account for Tajikistan (Yunusov 1978) reported the species as cultivated and sometimes escaping from cultivation, without further details on the alien status. No information on any particular subspontaneous occurrence in the country has been found. Nowak et al. (2020) claimed the species status of archaeophyte in the country, but the status is clearly in error.

Western Tian-Shan (Fig. 3).

Figure 3.  

The confirmed alien record of Armoracia rusticana in Kyrgyzstan.

The background for the information in Deza (1989) is uncertain and may be an assumption or extrapolation. So far, we have not observed the species in ruderal localities in urban areas. The subspontaneous presence of the species in Kyrgyzstan is supported by our observation of its occurrence in a single locality in the Sary-Chelek Nature Reserve, where it grows on a roadside meadow immediately north of Arkyt Village.

Neophyte.

Our record of Armoracia rusticana in the Sary-Chelek Nature Reserve is dated 2005. Following the report of Deza (1989), we assume that the first alien occurrences in the country were observed no later than in the 1970s-1980s, whereas its original introduction was made by the first Russian colonists.

Escape from confinement: Agriculture.

The species is known exclusively as escaping from cultivation. Its further spread has not been observed.

Eastern Europe.

The species was introduced by settlers and suppliers from Eastern Europe.

Casual.

Established populations have not been observed. The colony in the Sary-Chelek Nature Reserve is locally persisting.

Agriculture - no impact (not occurring as a weed). Native ecosystems - minor impact (occurrence near populated places). Urban areas - minor impact (ruderal occurrence).

Declining (inferred).

The popularity of Armoracia rusticana was noticeably fading during the second half of the 20^th century and now it has gone out of fashion as a garden vegetable. Nevertheless, the species keeps its ruderal presence in the territory due to its extraordinary ability for persistence and further spread with disturbed ground.

Asia Minor, Caucasus, Near East, Iraq, Iran, Turkmenistan (mountains), Afghanistan, Pakistan (Khalilov 1993).

Central Asia (Kazakhstan, Kyrgyzstan, Tajikistan, Uzbekistan).

Kazakhstan, Kyrgyzstan, Tajikistan, Uzbekistan (Fig. 4).

Figure 4.  

The current distribution of Crambe orientalis in Central Asia, according to the specimens examined, documented observations (iNaturalist 2024, Plantarium 2024) and reliable publications (Nikitin and Geldykhanov 1988, Nobis et al. 2016).

In Kazakhstan, the species is known from a vast area along the north-western Tian-Shan (Botschantzev 1977, Lazkov and Redina 2007). It is currently known also from several localities in southern Kazakhstan from Almaty to Lake Balqaş (Nobis et al. 2016, iNaturalist 2024, Plantarium 2024) and in one isolated locality in northern Kazakhstan, Karagandy Town (Plantarium 2024).

In Uzbekistan, the species was found in the eastern part of the country, mostly adjacent to Kazakhstan (Botschantzev 1977) and recently also in an isolated locality in the south, near Boysun Town (previously unpublished record).

In Kyrgyzstan, the species was first reported from the Chüy Depression, north of Bishkek (Lazkov and Redina 2007) and then from the Talas Depression, the western part of the country at the border with Kazakhstan (Lazkov and Sennikov 2014).

In Tajikistan, the species was recently found as naturalised in agricultural areas along the Mogendarya River (Nobis et al. 2016). This locality is not connected with the native distribution area in the adjacent Afghanistan because the species has not been found along the Amudarya River in the northern part of that country (Breckle et al. 2013).

In Turkmenistan, the species is native along the mountains in the southern parts of the country (Nikitin and Geldykhanov 1988). No alien localities are known.

In Central Asia, Crambe orientalis was found for the first time on a fallow field at Jeri post station (Leninskoe Village in the Soviet times, Kazygurt Village in Kazakhstan) along the road from Tashkent to Şymkent, in present-day Kazakhstan, in 1922. To develop on that field, this slow-growing perennial species must have been introduced a few years before its sampling, i.e. already in the Imperial times. We do not have any written or even indirect evidence regarding the origin of this record, but it can be inferred from published side evidence. As the species is not a segetal weed, it must have been introduced for cultivation, as an edible or forage plant. Already in the mid-19^th century, the Caucasian Society for Agriculture (established for public edication in Tiflis, now Tbilisi, in 1850) has widely advertised the culinary values of the cultivated C. maritima L. and its wild relatives (Kolodeev 1853) in the Caucasus. The society offered seed material from Tiflis, which was easy to collect also in native populations of C. orientalis, occurring in the vicinity of the city (Grossheim 1950). The seed distributed by the society was the most likely source for the early experimental cultivation of C. orientalis in Central Asia.

As evident from numerous herbarium specimens collected in that area, the field at Jeri became the source of the species invasion, which also covered the neighbouring villages along the main road (Botschantzev 1977) and expanded to natural habitats (Butkov and Mailun 1962). In the 1950s, the species was found also south of Tashkent, spreading along the Chirchik and Pskem Rivers, which are adjacent to the place of the original introduction. Currently, it is widely distributed along the north-western Tian-Shan, forming extensive populations especially in arable lands (Fig. 5), but also ascending to the mountain slopes from river valleys (German, pers. obs.).

Figure 5.  

Alfalfa field with a naturalised population of Crambe orientalis in full blossom along the Kökbūlaq River near Pisteli Village, Türkıstan Region, Kazakhstan (photo by E. Belousov, 21 May 2021). Source: https://www.plantarium.ru/page/image/id/695395.html (Plantarium 2024).

In the 1950s-1970s, Crambe orientalis was cultivated on experimental fields and in gardens in Uzbekistan and Kyrgyzstan as a forage or ornamental plant (Amirkhanov et al. 1974, Kadyrkulova 1987). It was recommended for cultivation and, according to herbarium records, used widely in Central Asia. Naturalised remnants of its former field cultivation were found in Uzbekistan (Boysun), Tajikistan (Mogendarya) and Kyrgyzstan (Chüy Depression), whereas its former ornamental cultivation, documented in Uzbekistan (Tashkent, Yangidarya), Kyrgyzstan (near Bishkek) and Kazakhstan (Almaty, Karagandy), also produced locally established populations.

Although the field and garden use of the species is no longer popular, it continues spreading from the places of its former cultivation. Its expansion, well documented in many areas, shows a high potential for the future invasion.

Western Tian-Shan, Northern Tian-Shan (Fig. 6).

Figure 6.  

The current distribution of Crambe orientalis in Kyrgyzstan.

The species is known from two separate areas in the Western and Northern Tian-Shan. The single locality in the Western Tian-Shan, discovered in 2013 (Lazkov and Sennikov 2014), is a direct continuation of the first invasion that started between Tashkent and Şymkent. Several localities around and north of Bishkek belong to an area of the species invasion in the Chüy Depression (Fig. 7), which has been repeatedly sampled since 2006 (Lazkov and Redina 2007).

Figure 7.  

Ruderal occurrence of Crambe orientalis along an irrigation ditch in the field area near Kamyshanovka Village, Chüy Region, Kyrgyzstan (photo by G. Lazkov, 11 July 2011).

The species was found mostly on the plain and in foothills, but also cultivated in gardens at elevations up to 1600 m a.s.l.

Neophyte.

The species was originally introduced In the late Soviet period, when the plants were used in experimental field cultivation (Kadyrkulova 1987). In the 2000s, naturalised populations have already been found.

Escape from confinement: Agriculture. Escape from confinement: Ornamental purpose other than horticulture. Unaided: Natural dispersal across borders.

The primary way of the species introduction was its cultivation on fields for fodder and in private gardens as ornamental plants. The species is known to run wild from the places of original cultivation and this was the cause of its introduction in the Chüy Depression (from fields) and around Bishkek (from gardens).

The secondary dispersal of the species occurs actively by wind. This was the cause of introduction in the Talas Depression in Kyrgyzstan, to which the plants have arrived from the neighbouring areas in Kazakhstan.

Caucasus.

Native Caucasian populations were accessible as a source of cultivation in the Russian Empire and the USSR.

Naturalised.

The species is apparently naturalised in the Chüy Depression, where it has been repeatedly observed for nearly 20 years.

Agriculture - minor impact (may occur in arable lands). Native ecosystems - minor impact (may colonise natural landscapes from agricultural lands). Urban areas - minor impact (sometimes found along roadsides and in ruderal places).

Increasing (observed and inferred).

The species actively expands in Central Asia. Its recorded occurrence in Kyrgyzstan has also been growing constantly.

The species distribution covers south-eastern Europe (Bulgaria), southern part of Eastern Europe (including the neighbouring parts of Slovakia), north-western Caucasus and Asia Minor (Tzvelev 1959, Kotov 1979, Jalas and Suominen 1994).

Europe (Tzvelev 1959, Jalas and Suominen 1994), Northern Asia (Chepinoga et al. 2024), North America (Dorofeev 2013).

The species has been extensively cultivated in Eastern Europe (Tzvelev 1959, Kotov 1979), Siberia (Tzvelev 1959) and known as escaping from cultivation in these territories (Tzvelev 1959, Kotov 1979). Its occurrence in Central Asia remained very obscure until Lazkov et al. (2011) reported an alien record from Kyrgyzstan. Our data suggest that this is the only species of the H. matronalis group that is commonly cultivated in Central Asia.

According to the herbarium specimens cited by Tzvelev (1959), the species has been cultivated in Eastern Europe at least since the mid-19^th century and found as escaped from cultivation in Siberia (Omsk Town) in 1886. Although it was common in ornamental cultivation already in the 19^th century, its alien occurrence in Siberia has been registered rather recently; to date, in Northern Asia, it is known from Western Siberia and Altai (Chepinoga et al. 2024).

In North America, the species is most common among the cultivated and alien members of the H. matronalis group, which is widely naturalised in the USA (Rollins 1981) and occurs in many states of the USA and also in Canada (Dorofeev 2013).

Kazakhstan, Kyrgyzstan, Uzbekistan (Fig. 8).

Figure 8.  

Cultivation and subspontaneous occurrence of Hesperis pycnotricha in Central Asia according to the specimens examined and documented observations (iNaturalist 2024, Plantarium 2024).

As evident from herbarium collections, the species was cultivated in southern Kazakhstan since the last decades of the 19^th century ("Flora iliensis" = Ili River Basin [most likely Almaty Town], 1886, A.N.Krasnov (LE)), i.e. from the beginning of its settlement by Russian colonists. The long tradition of ornamental cultivation suggests that the species is present in ruderal habitats. Such occurrences (Fig. 9) have been found on online citizen-science platforms (iNaturalist 2024, Plantarium 2024) and provide evidence for the species naturalisation or long-time persistence in the country. This is the first record of the subspontaneous occurrence of Hesperis pycnotricha in Kazakhstan.

Figure 9.  

A ruderal occurrence of Hesperis pycnotricha (pink flower variant) in Karagandy Town, Kazakhstan (photo by I. Evdokimov, 13 May 2020). Source: https://www.plantarium.ru/page/image/id/656303.html, misidentified as H. matronalis (Plantarium 2024).

In Uzbekistan, the species is cultivated in populated places, but not considered as running wild (Sennikov et al. 2020). Its first herbarium collection from cultivation is dated by the 1930s (Tashkent, in a garden of P.A.Baranov, 19.06.1932, A.Lapin (LE)).

In Kyrgyzstan, Hesperis pycnotricha was reported as being cultivated and occasionally escaped from cultivation under the wrong name H. matronalis (Deza 1989). Its later record as new to Kyrgyzstan and Central Asia as a whole (Lazkov et al. 2011) was the first documented observation of the species dispersal. The occurrence of the species in a spruce forest of the Jety-Ögüz River ravine (Lazkov et al. 2011) may look strange when considered isolated from the context because it misleadingly hints at the wilderness. The ravine is a popular touristic attraction and a path along the river starts from the sanatorium that is famous for its geothermal springs. The species was apparently dispersed to the wild from flowerbeds in touristic places.

In Tajikistan, the species is apparently cultivated, but we have no documentation of its occurrence.

Northern Tian-Shan (Fig. 10).

Figure 10.  

The subspontaneous record of Hesperis pycnotricha in Kyrgyzstan according to the specimen examined.

Neophyte.

The species was introduced most likely during the same period as in Uzbekistan and Kazakhstan, i.e. the last quarter of the 19^th century, due to the common market of garden cultivation in the Russian Empire. The beginning of its running wild is uncertain, but ruderal occurrence is highly likely from the beginning of cultivation.

The first published observation of its alien status belongs to the 1980s (Deza 1989) and the first observation in native habitats is dated 2009 (Lazkov et al. 2011).

Escape from confinement: Ornamental purpose other than horticulture.

The plants were cultivated outdoors for ornamental purposes and run wild from the places of cultivation.

Seed dispersal on human feet is a likely vector of the secondary dispersal, as the species is often observed growing along pedestrian paths.

Eastern Europe.

The species has been repeatedly introduced via the ornamental seed supply of the Russian Empire and the USSR.

Casual.

The ruderal occurrences of the species in Kyrgyzstan (Deza 1989) should be casual as no such naturalisation is currently known. The species status in a single locality recorded in the Teskey Alatoo (Lazkov et al. 2011) is unknown as the locality description is unavailable. We prefer to treat the species status as casual (Sennikov and Lazkov 2024a) until naturalised populations or at least persisting colonies are known.

Agriculture - no impact (not recorded in crop production areas). Native ecosystems - minor impact (once recorded in recreation forest areas, may be found elsewhere outside populated places). Urban areas - minor impact (sometimes escapes and occurs in ruderal places).

Slowly increasing (inferred).

The species has long been highly popular in ornamental cultivation. Its wide use for flower beds and in private gardens constantly increases the risk of unintentional introduction. Further discoveries of locally persisting or even naturalised populations are expected, as evident from the current expansion of the species in Siberia (Ebel 2002).

Mediterranean, including north-western Africa, south-western Europe, Italy, Greece, Crimea, Asia Minor, Near East, Transcaucasia, Iran and south-western Turkmenistan.

Europe, South Africa, temperate North and South America, Australia, scattered localities in Asia.

In North America, the species was noted in California first in 1895 and as a noxious weed in the 1930s (Jepson 1936). It is widely naturalised in the western states of the USA (Rollins 1981) and Mexico (Villaseñor and Espinosa‐Garcia 2004).

In South America, the species has developed an extensive occurrence in argicultural areas (GBIF 2024), which is also connected with the species dispersal with imported wheat to Europe, as recorded in Finland already in the 1950s (Suominen 1979).

In Australia, Hirschfeldia incana was introduced in the late 19^th century and became naturalised in the very beginning of the 20^th century. Its significant field occurrence and grain contamination has been observed in the south-eastern provinces (Parsons and Cuthbertson 2001), causing the species immigration to Finland with Australian contaminated wheat in the 1950s (Suominen 1979).

The territories of the extensive naturalisation of Hirschfeldia incana correspond to grain production areas, thus indicating its major distribution pathway with imported grain. Grain import as a major pathway is indicated by the species occurrence along railway tracks, for example, in Lithuania (Gudžinskas 1997) and North-Western European Russia (Tzvelev 2000). The secondary dispersal takes place along roadsides by attaching seeds to vehicles and feet, by road construction and with flowing water (Parsons and Cuthbertson 2001).

A recent expansion of the species in Britain is connected with the increasing trade of contaminated bird seed since the 1990s (Patel 2004). In addition to the previous spread of the species by bread grain trade, we suggest that its recent global dispersal may be largely caused by the increasing production of poultry in the Developing World since the 1990s (Narrod et al. 2008), which requires extensive import of grain food that is not sufficiently available in arid countries of Asia, whose climate may be suitable for the species naturalisation.

The exact extension of the secondary spread of Hirschfeldia incana may not be properly documented because its occurrences are largely ephemerous due to its high demand for warm temperatures; this can be demonstrated with an example of Finland in which numerous species records exist because of the dedicated sampling for exotic alien plants (Suominen 1979). Outside the areas with high summer temperatures, its populations are mostly temporarily persisting and not really established.

Kyrgyzstan, Tajikistan, Turkmenistan, Uzbekistan (Fig. 11).

Figure 11.  

The native and alien records of Hirschfeldia incana in Central Asia, according to herbarium specimens examined and reliable literature (Nardina 1954).

In Central Asia, the species was first found in Turkmenistan in 1946, in a single locality at Ajyýap Village, present-day Esenguly District, Balkan Province, along field margins and in saline lands (Nardina 1954), although the voucher specimen is currently lacking (Voitenko 1969). In this area, segetal weeds were numerous and especially abundant along the river (Nardina 1954), thus showing a developed agricultural activity.

The first record of Hirschfeldia incana in Turkmenistan seems to have been connected with an agricultural region in Turkmen Sahra, Golestan, Iran, a territory historically inhabited by the Turkmen people who were otherwise largely nomadic. Herbarium records from this region uncovered a continuous distribution of the species (Fig. 12). This distribution strongly suggests that the species was present in the territory before the Russian conquest of Turkmenistan. Its status can be inferred as presumably native in south-western Turkmenistan because of its numerous occurrences in the lowlands of Turkmen Sahra, not only as a weed, but also in native plant communities and natural landscapes, as noted by Nardina (1954).

Figure 12.  

The presumably native distribution of Hirschfeldia incana in north-eastern Iran and Turkmenistan, according to Nardina (1954) and Hedge (1968).

One more historical locality, along the railway near Kushka Station, was observed in 1968 (Voitenko 1969). This occurrence is apparently connected with the imported wheat grain, from the times of the Soviet food crisis (Volin and Walters 1965, Moravcik 1978); otherwise, the species would have been noticed in that place earlier, in the course of its botanical exploration since the early 20^th century.

In Kyrgyzstan, the species was first observed as a casual alien in Kyr-Koo Village in 2013 (Lazkov and Sennikov 2014). The second record, dated 2022, is reported in the present contribution.

In Tajikistan, the species has been recorded only once, as a recent casual introduction in a ruderal place in Dushanbe City, in 2019 (Ebel et al. 2022).

The species records in Uzbekistan are most recent in Central Asia (German et al. 2024). In a single year, during 2024, it has suddently emerged in several localities along roads and on city lawns in Tashkent and north-eastern parts of Uzbekistan, often as groups of several individuals. We assume that this introduction has originated from the recent import of foreign fodder grain.

Western Tian-Shan, Alay-Turkestan (Fig. 13).

Figure 13.  

The documented occurrence of Hirschfeldia incana in Kyrgyzstan.

After the first record (Lazkov and Sennikov 2014), the species has been recently observed in Sary-Talaa Village in south-western Kyrgyzstan (Fig. 14).

Figure 14.  

Hirschfeldia incana in Sary-Talaa Village, Jalal-Abad Region, Kyrgyzstan (photo by G. Lazkov, 5 July 2022).

Neophyte.

The species has been observed during the independence time, since 2013.

Transport - Contaminant: Seed contaminant.

Both localities observed in Kyrgyzstan are linked with the import of contaminated grain. The species occurrence along ruderal roadsides strongly suggests its immigration without agricultural activities.

According to the recent reports of the National Statistic Committee of the Kyrgyz Republic, reproduced in the local news media, Kyrgyzstan largely depends on the massive import of fodder for local farming, also from remote areas like Iran. Fodder grain is used, for example, for feeding chickens in the villages and we assume this country as a likely source of introduction because Hirschfeldia incana is broadly distributed in Iran (Hedge 1968).

Casual.

The ruderal roadside occurrences observed in Kyrgyzstan are limited in size and do not demonstrate that the species has been naturalised and formed sustainable populations.

Agriculture - no impact (not found in cultivated lands). Native ecosystems - no impact (restricted to populated places). Urban areas - minor impact (rarely occurs in ruderal places).

Increasing (observed and inferred).

With the latest spread of the species in Uzbekistan (German et al. 2024), we predict that further occurrences may emerge in the future because of the continuous import of contaminated grain fodder. However, the species naturalisation is not expected in arid areas of Kyrgyzstan.

From the species ecology and details of its distribution, we infer that the native distribution area of Mutarda arvensis is the Mediterranean. Its eastern distribution limit is uncertain, but apparently does not include Turkmenistan, in which the species is considered exclusively alien and originally occurring as a segetal weed in irrigated places of lowlands and foothills (Nikitin and Geldykhanov 1988).

Europe, temperate Asia, temperate Africa, temperate North and South America, non-desert Australia. It is found northwards as far as Iceland and the Faroes in the Arctic (Fogg 1950, Wasowicz et al. 2019). Common in North America (Rollins 1981).

The species is a common weed of many crops (Yarmolenko and Vasilczenko 1934) since the early periods of agriculture (Fogg 1950) and was recorded on traditional fields of bread crops and flax in Afghanistan (Vavilov and Bukinich 1929). Its high level of seed production and a good adaptation to arable lands brings its distribution to the limits of argicultural zone; its highest abundace is recorded in lowlands and on chernozem soils (Yarmolenko and Vasilczenko 1934), but the occurrence extends to the higher elevations with the cultivation of cereals (Fogg 1950). Its typical pathway of introduction is infestation of crop seeds and argicultural commodities (Yarmolenko and Vasilczenko 1934, Suominen 1979), making it commonly occurring also in waste and ruderal lands and along roadsides in populated places. This pathway is still active, although apparently decreasing because of the modern purification of grain crops (Vainorienė and Gudžinskas 2009). Due to its enormous seed deposit, the species commonly occurs on fallow fields, but disappears when the fields are turned into pastures (Chippindale and Milton 1934).

The species occurs as a common alien plant in all the countries of Central Asia (Yarmolenko and Vasilczenko 1934, Kovalevskaya 1974). It occurs largely in agricultural areas, in the steppe zone in Kazakhstan and on irrigated lands in the mountains, largely avoiding deserts (Fig. 16) due to its rather high demand for water supply (Yarmolenko and Vasilczenko 1934).

Figure 16.  

Recorded distribution of Mutarda arvensis in Central Asia, according to herbarium specimens, documented observations and literature data (Yunusov 1978).

The spread of Mutarda arvensis to Central Asia has occurred in several major waves from different directions.

Fedtschenko (1902), when visited Samarqand immediately after the Russian conquest, collected the species around the city in 1869. In Uzbekistan, as well as elsewhere in the mountainous Central Asia, the species is an archaeophyte that had arrived with the introduction of agriculture in the Neolithic period and its population in the southern Central Asia was apparently self-sustainable in agricultural lands for a long time. During the Imperial and Soviet times, the development of extensive agricultural regions, which were largely specialised on cotton and grain production, resulted in the abundant occurrence of Mutarda arvensis in southern Uzbekistan, south-western Tajikistan, Fergana Depression and northern Kyrgyzstan (Fig. 16).

Northern Kazakhstan, embracing the steppe areas of Central Asia, was a nomadic region, into which the species has arrived with the agriculture introduced by Russian settlers. Slovtsov (1897), who travelled across Akmolinsk steppes (present-day Kökşetau District, Astana Region, Kazakhstan) in 1878, observed that permanent settlements with agricultural activities were few and belonged to Russian Cossacks who served as frontier guards along the Siberian frontier and in its foreposts since the second half of the 18^th century; two early herbarium collections of the species from Kazakhstan (dated 1834 and 1878) originated from the Cossack settlements. In 20 years after this observation, northern Kazakhstan has been settled by many tens of thousands of Russian peasants, who established numerous villages and extended the cultivated lands, thus producing the second wave of the species invasion (Katanaev 1897). The third wave originated from the machinery-supported expansion of agriculture into the Asian part of the USSR (Katkoff 1950, Durgin 1962), which appeared in periods of the intensive ploughing up of previously uncultivated lands in Siberia and northern Kazakhstan in 1928-1940 and culminated with the Virgin Lands campaign of 1954-1963.

According to herbarium collections, in Central Asia, the species was found in connection with all kind of fields: wheat, barley, oat, flax, alfalfa, cotton, vegetable, beetroot. It was also found on city lawns and among ornamental plants.

The ruderal occurrence of Mutarda arvensis in contemporary populated places of Central Asia is complementary to the other factors. Its origin comes partly from grain contamination, partly from the infestation of ornamental cultivation or greenery.

The major floristic sources reported that the species is commonly found in Central Asia as a field weed, on fallow fields, as a ruderal plant in populated places and along roadsides (Botschantzev and Vvedensky 1955, Nikitina 1955, Vasilieva 1961, Kovalevskaya 1974, Yunusov 1978). This information reflects its major role as a segetal weed and does not provide for its naturalisation in native habitats. According to more recent observations, Mutarda arvensis has been repeatedly found as dispersed outside fields and ruderal places to the neighbouring riversides and ravines. These observations show the species capacity to establish in natural habitats, although to a limited extent.

The species was found in all agricultural regions of the country (Nikitina 1955), but its current documentation is apparently deficient (Fig. 17).

Figure 17.  

Documented records of Mutarda arvensis in Kyrgyzstan.

According to the current record, Mutarda arvensis was primarily collected from argicultural lands (Fig. 18) in northern and eastern Kyrgyzstan. It was observed in fields at elevations from 750 to 2150 m a.s.l., with the common presence in the high-elevated Northern and Eastern Tian-Shan, contrary to the statement of Yarmolenko and Vasilczenko (1934) that the species prefers elevations below 1000 m a.s.l.

Figure 18.  

A wheat field with Mutarda arvensis near Karkara, Ysyk-Köl Region, Kyrgyzstan (photo by G. Lazkov, 15 June 2013).

Its major presence in the country is registered on agricultural lands and ruderal places, including roadsides. The species was also not uncommonly found in natural, though usually disturbed habitats, like gravelly riversides, clayey deserts and meadows. The most remarkable case of its dispersal was observed in the western spurs of the Kök-Shaal Range, Eastern Tian-Shan, close to the Chinese border, where the species was found in 1939 in an uninhabited ravine at an elevation of ca. 2900 m a.s.l. This occurrence demonstrates its potential dispersal to the remote wilderness with horse fodder, mostly composed of grain, which has been commonly taken by shepherds and mounted guards to the mountains and deserts.

Besides the extensive weedy distribution, Mutarda arvensis has been cultivated for oil seed (Nikitina 1955). Its cultivation remains popular to date and accounts for a part of the alien occurrence, when the plants persist as ruderal or weedy leftovers of the former cultivation.

Archaeophyte.

From the archaeophyte status of the species in Central Asia, we infer its first appearance in the territory of Kyrgyzstan in pre-historic times, through the agriculture in the Ferghana Depression.

Transport - Contaminant: Seed contaminant. Escape from confinement: Agriculture.

Mutarda arvensis is a common contaminant of grain, fodder and ornamental seed and its primary alien occurrence originated from cultivated lands. Crop trade and accompanying losses in transportation and discharge places account for the ruderal occurrence of the species.

The species cultivation for oil seed contributes to its alien occurrence.

The secondary dispersal is limited and occurs primarily by winds and water currents along rivers.

Iran, with the development of the Neolithic agriculture. Eastern Europe, with modern crop cultivation. Other sources are possible with imported grain.

Naturalised, not invasive. The species persists for uncertain time around the places of original introduction, intruding into neighbouring natural habitats, although its continuous presence in the territory may largely rely on the constant arrival of new diaspores through contaminated seed (like in the case of Xanthium strumarium: Sennikov and Lazkov (2021)).

Agriculture - major impact (noxious weed of all crops, in fields and gardens). Native ecosystems - moderate impact (occurring along streams and roadsides near populated places). Urban areas - moderate impact (ruderal occurrence).

Stable (observed).

Central, Eastern and South-Eastern Europe (including the zones of deciduous forest, forest steppe and steppe: Jonsell (1973)), Asia Minor, Caucasus, Western Siberia (adjacent to Europe), Central Asia (north-western Kazakhstan).

Western and Northern Europe, southern Siberia, Central Asia (mountains), East Asia, North America.

Kazakhstan, Kyrgyzstan, Tajikistan, Uzbekistan. The distribution is mapped on the basis of herbarium specimens and published observations (Fig. 20).

Figure 20.  

Native and alien occurrence of Rorippa austriaca in Central Asia according to herbarium specimens examined and documented observations (iNaturalist 2024, Plantarium 2024).

In Central Asia, the species was first recorded as alien in Tajikistan, where a small, but established population was found in Dushanbe by Dorofeev (1984). The population, recorded in 1982 in the botanical garden of the Institute of Botany, Academy of Sciences, was found along an irrigation ditch; its age was estimated below 10 years.

In Kyrgyzstan, the species was found for the first and only time in Bishkek, as a weed of ornamental cultivation in 2009 (Lazkov et al. 2011).

In Uzbekistan, it was first found on a ruderal lawn in Tashkent in 1992 (German et al. 2013). Its continuous occurrence on city lawns has been subsequently confirmed in 2015 (Plantarium 2024).

In Kazakhstan, the species is native in the steppe zone of the north-western regions of the country (Vasilieva 1961, Jonsell 1973); its easternmost limit coincides with the Mūğaljar Mts. (the southern extension of the Urals). As an alien, it was recorded once (Fig. 21) from a lawn in Şymkent Town in 2023 (Ebel et al. 2024).

Figure 21.  

A stand of Rorippa austriaca on a lawn in Şymkent, Kazakhstan (photo by A. Ebel, 15 May 2023). Source: https://www.inaturalist.org/observations/247918250 (iNaturalist 2024).

Northern Tian-Shan (Fig. 22).

Figure 22.  

The record of Rorippa austriaca in Kyrgyzstan.

Rorippa austriaca was found in Bishkek in 2009, recorded on a "lawn" (actually, among ornamental roses in block planting) in front of the main building of the Academy of Sciences in Bishkek (Lazkov et al. 2011).

Neophyte.

As evident from the first records in Tajikistan and Uzbekistan, the introduction of Rorippa austriaca to Central Asia has started in the late 1970s - early 1980s (Dorofeev 1984, German et al. 2013). The first observation of this species in Kyrgyzstan was dated by the post-Soviet period, by 2009 (Lazkov et al. 2011), but the actual introduction period may have started slightly earlier.

Transport – Contaminant: Contaminant nursery material.

All observations in Central Asia have been made on cultivated lawns or flower beds (Dorofeev 1984, Lazkov et al. 2011, German et al. 2013, Ebel et al. 2024). These observations strongly indicate that the species was introduced with contaminated garden soil, transported with planting material and with contaminated seeds.

The species has a potential to spread along irrigation ditches, but no secondary dispersal has been observed in Kyrgyzstan.

Introduced with ornamental plants via East European and then international nurseries.

Casual (ephemeral, extinct).

The only population registered in 2009 was ephemerous; it has been removed by management soon thereafter (Lazkov, pers. obs.). Further records are expected elsewhere and in the future, but not observed, likely due to the shortage of botanical observations.

Agriculture - minor impact (minor garden weed of infrequent occurrence). Native ecosystems - no impact (restricted to agricultural and urbanised areas). Urban areas - minor impact (rarely occurs in recreation places).

Unknown, but no apparent increase observed.

Europe (Northern Europe excepted), Asia Minor, Caucasus, Iran.

Northern Europe, Northern, Central and Eastern Asia, China, Northern Africa, Northern and Southern America. In its northern limit, the species reaches as far as the true Arctic in Iceland and Svalbard (Wasowicz et al. 2019). In Northern Asia, it is found across southern Siberia and in the Far East (Chepinoga et al. 2024). The species is highly invasive, at the active stage of expansion (Ebel 2016).

Jonsell (1968) has analysed the early records of Rorippa sylvestris in North-Western Europe (from the Great Britain to Finland) and concluded that the oldest pathway of its dispersal was with ship ballast and boat traffic, but this pathway became obsolete already in the 19^th century and the early arrivals made no practical contribution to the recent invasion. The dramatic increase in the species distribution in Northern Europe was apparently connected with the intense gardening and transportation of the garden commodities, which has been especially noticeable since 1915 (Jonsell 1968).

The distribution, spread and invasion potential of Rorippa sylvestris in Siberia, a large region adjacent to Central Asia, have been described in detail and documented by A. Ebel (Ebel 2000, Ebel 2016). He noted that the species was first collected as a weed in the botnical garden of the Tomsk University as early as 1925 and in many populated places in more recent times, thus indicating its arrival with gardening and garden commodities. Very remarkably, its numerous rather early records in 1933 and then in the 1960s-1990s are linked with the occurrence in natural wetland habitats, supporting the idea that the species may have been partly dispersed by waterfowl - at least spreading locally in this way, but likely also involving long-distance dispersal from man-disturbed habitats colonised by the species (Ebel 2000).

In North America, Rorippa sylvestris has been common in the main area east of the Mississippi River in north-eastern United States and southern Canada (Rollins 1981), where it occurs in natural wet habitats along rivers and waterbodies and in gardens, with the first record published in 1818 (Stuckey 1966, Stuckey 1972). Similarly to the situation in Sweden (Jonsell 1968) and Siberia (Ebel 2000, Ebel 2016), the broad occurrence or even prevalence of the plants in natural habitats required the researcher to undertake special analysis to obtain evidence for an introduced status in the New World. The first species colonies appeared as a result of long-distance dispersal, mostly to large sea and river ports (Stuckey 1966). Groh (1936) noted that the species was spread mostly with nursery stock in the 20^th century, whereas Stuckey (1966) considered rivers as a major corridor in the secondary dispersal.

Scattered records of Rorippa sylvestris at mills (Hanssen and Nordhagen 1930) indicate its potential ability to immigrate as grain contaminant. It is known to occur as impurity in grass seed (Salisbury 1961), thereby spreading to city lawns.

Both in its native and secondary distribution area, the species may abundantly invade cultivated lands on fertile soils and with sufficient water supply. Notably, its abundant occurrence in forest nurseries in Sweden (Bärring 2008) indicates a strong potential of the species to infest almost any kind of rooted saplings in commercial distribution, which played a major role in its secondary dispersal by man.

Kazakhstan, Kyrgyzstan, Tajikistan, Uzbekistan (Fig. 23).

Figure 23.  

Distribution of Rorippa sylvestris in Central Asia according to herbarium specimens and documented observations (iNaturalist 2024, Plantarium 2024).

In Central Asia, Rorippa sylvestris was first recorded in Uzbekistan, where it was found in a garden in Tashkent (Popov 1924). The documenting specimen was collected in 1919. Since then, the species has been repeatedly collected or observed as a weed or ruderal plant in Tashkent and keeps its presence as noted in recent local observations (e.g. Tillaev and Gaziev (2021)). It was also found in ruderal places in Samarqand in 1940 (Botschantzev and Vvedensky 1955) and Qarshi in 2024 (iNaturalist 2024).

The occurrences in Tashkent and Samarqand remained isolated in Central Asia until rather recent times (Shermatov 1974).

The first species record from Kyrgyzstan, noting its occurrence in Bishkek and vicinities (Jonsell 1973), has been commonly neglected in regional literature. The species distribution in the country is detailed for the first time in our present work.

In Tajikistan, the species has been found in 1982 in the botanical garden of the Academy of Sciences in Dushanbe, as a weed in ornamental cultivation and as a ruderal plant along irrigation ditches (Dorofeev 1984). It was subsequently observed in the city in 2017-2018 (Ebel et al. 2020).

In Kazakhstan, the species was first found along rivers within two large towns, Ust-Kamenogorsk in 1967 and 2002 (Ebel 2000, Ebel 2002) and Semipalatinsk in 2002 (Ebel 2002, Ebel and Ebel 2003).

Western Tian-Shan, Northern Tian-Shan (Fig. 24).

Figure 24.  

The currently known distribution of Rorippa sylvestris in Kyrgyzstan according to herbarium specimens and documented observations.

Rorippa sylvestris was first collected in Kyrgyzstan in 1955, near Jangy-Jer Village in the Chüy Depression, north of Bishkek City. In the same area, the species was subsequently collected in Bishkek (city centre) and along the Ala-Archa River which streams from the mountains through Bishkek. To date, the plants have been found in several places along this river (Fig. 25), from the mountains to the lowland.

Figure 25.  

A stand of Rorippa sylvestris along the Ala-Archa River above Bishkek City (photo by T. Carlisle, 23 July 2016). Source: https://www.inaturalist.org/observations/4131981 (iNaturalist 2024).

One more historical locality, also dated 1955, is known from the walnut forest area near Arstanbap Village. This locality has not been taken into account in the previous publications (Sennikov and Lazkov 2024a) and is formally reported as a new record here.

The localities are situated in the lowlands (700-800 m a.s.l.), foothills (1150 m a.s.l.) and the lower mountain belt (1300-1700 m a.s.l.).

Neophyte.

As the species is rather conspicuous, it is unlikely that its occurrence has long been neglected in the proximity to the capital and its botanical activities (cf. Stuckey (1966), Jonsell (1968), Ebel (2000)). With the first herbarium collections made in 1955, we may safely assume that the species was introduced in the late 1940s or early 1950s.

Transport – Contaminant: Contaminant nursery material.

Since 1948, when the Communist Party of the USSR and the Soviet Government had announced that forest plantations are crucially important for agricultural productivity, territories of the Chüy Depression near Bishkek in Kyrgyzstan were involved in experimental planting of forest trees (Karafa-Korbut 1955). At that time period, planting trees became common also in the mountains, including nature reserves, as part of the programme for "improving" natural forests (e.g. Kotlar (1973)); we have observed remnants of such planting in many places in Kyrgyzstan, for example, the Sary-Chelek Nature Reserve (Lazkov and Ganybaeva 2021).

All occurrences of Rorippa sylvestris in Kyrgyzstan are linked to forest plantations (the oldest records in the Chüy Depression, Ala-Archa River and a walnut forest area near Arstanbap Village) or ornamental cultivation (Bishkek City). We assume nursery transport to be responsible for all these introductions.

The secondary dispersal may occur by waterflow and by water birds along watercourses.

Eastern Europe.

Naturalised.

The localities in the city may be ephemeral because of constant management, but the species is known as naturalised along the Ala-Archa River (recent observations in 2023: iNaturalist (2024)).

Agriculture - minor impact (the species is known as a weed of ornamental cultivation, although with low frequency and very limited distribution). Native ecosystems - minor impact (the species is locally spreading along natural and artificial watercourses). Urban areas - minor impact (the species occurs as a ruderal along pavements and irrigation ditches in populated places, with limited distribution).

Gradually increasing. The species is slowly expanding in native habitats and becoming more noticeable in the city.

Zhou et al. (2001) considered the native distribution of Sisymbrium irio to cover the circum-Mediterranean area, Iran and Central Asia up to western China (Xinjiang). This opinion was followed by POWO (2024). However, the native distribution of the species is highly obscured by its extensive secondary dispersal.

Phylogenetically, S. irio is most closely related to S. reboudianum Verl. and S. erysimoides Desf., which are native to the Mediterranean, in general and North Africa, in particular (Žerdoner Čalasan et al. 2021). We circumscribe the native distribution of this species as covering the Mediterranean area only.

The species is widely naturalised in temperate Europe, South-Western Asia and Iran, Central Asia, North and South America, South Africa and Australia (POWO 2024). Two major areas of the species invasion are linked to crop production. In south-western USA and Mexico, an extensive area of the species naturalisation (Rollins 1980, Rollins 1981, Rollins and Al-Shehbaz 1986, Rollins 1993) is linked with a variety of crops, for example, alfalfa, maize and sugarbeet, but natural semi-deserts also appear to be heavily infested. In Australia, the species is widespread in all states, but the south-eastern territories are particularly affected by its invasion (Martín-Forés et al. 2023, GBIF 2024), with a major presence in oilseed crops (Salisbury et al. 2018).

In Asia, the species presence in Turkey seems to be minor (Hedge 1965) and therefore its native status is unlikely there. It is considered a common weed in Iran (Hedge 1968), where it may be an archaeophyte rather than native; similarly, it is an old anthropogenous incomer that has been established in the Indian subcontinent (Khoshoo 1966). Isolated localities of casual introduction are known in many countries in the Northern Hemisphere, as far northwards as Finland (Suominen 1979).

In Europe outside the Mediterranean, the species has spread northwards already during the 17^th through 19^th centuries (Salisbury 1961), but remains mostly casual or showing a negative trend (e.g. McCollin and Geraghty (2015), Pyšek et al. (2022)), although being capable for long-term persistence under favourable local conditions, such as in its legendary place of presence, London (Trimen and Thiselton-Dyer 1869, Clapham et al. 1989).

The species can be a noxious weed in some areas, as in the south-western United States (Rollins 1980), where it also invades abandoned lands in deserts (Burgess et al. 1991).

Trading commodities around the Globe continues to contribute to the further expansion of S. irio, as indicated by a report from Southern Korea, where the species was recently introduced through a trading port (Kim et al. 2021). A similar introduction has been recorded earlier in Japan (Kawamata et al. 2018).

The species is widely distributed in Central Asia and has been recorded from Kyrgyzstan (Bondarenko 1974), Tajikistan (Yunusov 1978), Turkmenistan (Vasilczenko 1948) and Uzbekistan (Botschantzev and Vvedensky 1955). We have mapped its occurrence in Central Asia and neighbouring countries (Fig. 26) on the basis of herbarium specimens at ALTB, LE, MW, P, TASH and literature data (Vasilczenko 1948, Yunusov 1978).

Figure 26.  

Native and alien (not distinguished) distribution of Sisymbrium irio in Central Asia and neighbouring countries (those named in the map).

In Turkmenistan (Vasilczenko 1948), the species is relatively common in the mountainous area and has the same status as in Iran, i.e. likely an old archaeophyte, largely weedy. This part of the species distribution continuously extends from Iran and Afghanistan (Hedge 1968), except for the easternmost locality in the Kuhitang Mts. and the northernmost locality at the Caspian Sea, which are synanthropic.

In Uzbekistan, the species is found in several localities in the southern part (Hissar Mts.), from which it has been repeatedly collected since the 19^th century; the oldest specimen from Sherabad Town was collected in 1881 (Franchet 1883). Due to their early collection dates, all its southern localities have originated from introductions prior to the Russian expansion to the region, i.e. from the sources in Afghanistan, from which grain have been supplied (Panin 2017) to compensate for food shortage in southern Hissar (Iskandarov 2012). Grain immigration pathway remains active in modern times, as evident from recent observations in Buxoro Town and on fields near Boysun Town (Fig. 27), although its modern source is currently unclear.

Figure 27.  

A fallow field south of Boysun Town in Uzbekistan, abundantly covered by Sinapis arvensis, also hosted plants of Sisymbrium irio (photo by D. German, 13 April 2023).

In Tajikistan, the species is known only from two published observations, which were based on specimens collected near the southern country border in the 1960s (Yunusov 1978). Recently, S. irio was also mapped as present in western Tajikistan, Zeravshan River Valley (Nowak and Nobis 2020), but the background collections have not been verified.

In Kyrgyzstan, the only occurrence was reported by Bondarenko (1974) and accepted in the latest checklist (Lazkov and Sultanova 2011, Lazkov and Sultanova 2014). The report was based on a single specimen: “Maidantal, ascending along Ak-Buura River from Kojo-Kelan to Kayyingdy Pass”, 05.1913, Bronevski 154 (LE). This specimen was misidentified; it represents a flowering plant of Sisymbrium loeselii L. Moreover, Bondarenko (1974) misattributed its locality to the Fergana Range, thus misleading Sennikov and Tojibaev (2021) to include S. irio into their checklist of vascular plants of the Tian-Shan. The actual locality (Maidantal River, left tributary of Ak-Buura River) is situated in the Alay Range, which was explored by the botanical expedition of O. von Knorring in 1913 (von Knorring 1914).

Although we rejected the old record of S. irio in Kyrgyzstan, the species is reported from the country in the present contribution. There is another, obscure record of the species from rye fields in northern Kyrgyzstan, dated 5 May 2011 (Nowak et al. 2013), but we doubt its correct identity in the absence of publicly available herbarium specimens.

Alay-Turkestan.

Two individuals of the species were observed and collected by D.German in 2024 on a roadside in the central part of Kerben Town, Jalal-Abad Region (Fig. 28). Since the previous species occurrence in Kyrgyzstan (Bondarenko 1974) has been rejected as based on a misidentification, this finding is a new country record.

Figure 28.  

The confirmed alien record of Sisymbrium irio in Kyrgyzstan.

Neophyte.

The species has been recorded for the first time in 2024. Its first introduction may have gone unnoticed because of the ongoing flow of commodities from abroad, but the lack of earlier records suggests the rather recent arrival in the post-Soviet times.

Transport - Contaminant: Seed contaminant.

Three major pathways of introduction are known for the species. In Europe, it was most frequently found as a grain impurity (Suominen 1979, Rich 1991) or in wool waste (Pyšek 2005, Shimwell 2006). A recent, but seemingly minor means of introduction is soil contamination; the plant was found in containers in topsoil with imported ornamental plants in the Mediterranean trade (Hoste and Verloove 2010). In particular, this pathway was assumed in the latest report of S. irio from Siberia (Bolbotov et al. 2024).

In Kyrgyzstan, we can safely assume the species immigration with grain import. Further dispersal has not been observed.

Probably Uzbekistan, due to the trade within Central Asia.

As the plants were observed growing on a roadside without any direct connection with the source, their link with a particular commodity is uncertain. Sisymbrium irio is commonly introduced with wheat (e.g. Suominen (1979)), which may also be the case here, but its origin is uncertain. Wheat import has covered a third of the total consumption in Kyrgyzstan and this commodity has been recently imported mostly from Kazakhstan (Zorya et al. 2020) and, to a minor extent, from Russia, whereas S. irio is only a rare railway alien in Russia (Dorofeev 2002) and has never been reported from Kazakhstan (Abdulina 1999), so that the species immigration with grain from these countries is impossible. However, according to our observations, the species is present as a weed on wheat fields in Uzbekistan, from which some irregular import occurs, especially in border regions. Uzbekistan could be a likely origin of seed propagules of S. irio in Kyrgyzstan.

Casual.

The species persistence has not been observed. Its record in a populated place suggests casual introduction, with low chances for survival in this particular locality. However, future naturalisation is not excuded as the species exhibits a high capacity for naturalisation in semi-deserts (Rollins 1980, Rollins 1993) and its presence in Uzbekistan seems to be persistent.

Agriculture - no impact (so far, not recorded on fields, although recent surveys are lacking). Native ecosystems - no impact (not found outside populated places). Urban areas - minor impact (casual occurrence as a ruderal plant).

Increasing (inferred).

The high level of wheat import to Kyrgyzstan, which mostly occurs within the Central Asian region (Zorya et al. 2020), explains the recent introduction of S. irio to the country and demonstrates its potential for further spread with imported commodities.