Sisymbrium irio L., 1753

Sisymbrium irio L., 1753 View in CoL

Sisymbrium irio L. View in CoL , Sp. Pl. 2: 659 (1753).

Distribution

Native distribution

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.

Secondary distribution

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).

Distribution in Central Asia

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 View Figure 26 ) on the basis of herbarium specimens at ALTB, LE, MW, P, TASH and literature data ( Vasilczenko 1948, Yunusov 1978).

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 View Figure 27 ), although its modern source is currently unclear.

In Tajikistan, the species is known only from two published observations, which were based on specimens collected near the southern country border in the 1960 s ( 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.

Distribution in Kyrgyzstan

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 View Figure 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.

Ecology

Semi-deserts in the native distribution area; cultivated and abandoned lands, a variety of disturbed grounds in the secondary distribution area.

Biology

Sisymbrium irio is an annual or over-wintering herb ( Clapham et al. 1989).

The species is self-pollinating ( Khoshoo 1966). It has a quick development cycle and is capable of producing numerous small seeds, which are easy to disperse. The species exists on several ploidy levels (diploid, triploid, tetraploid, hexaploid and octoploid) ( Khoshoo 1955), which may facilitate its dispersal to different habitats and climate zones ( Khoshoo 1965).

Notes

The species can be confused with Sisymbrium loeselii , which differs from S. irio by petals (5) 6–8 mm long (vs. 2.5–3.5 (4) mm long) and hispid (vs. soft) pubescence, when present ( Yunusov 1978, Zhou et al. 2001, Al-Shehbaz 2015).

Introduction to Kyrgyzstan

Period of introduction

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.

Pathways of introduction

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.

Source of introduction

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.

Invasion status

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.

Evidence of impact

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).

Trend

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.