In the UAE, this species is known from the Hajar Mountains and from the Mazyad Oasis close to Jebel Hafeet (Jongbloed et al. 2003, M. Jongbloed pers. comm. 2019). Globally, the species occurs as a native species throughout most of Africa and around the Mediterranean basin, and has been very widely introduced across Asia and to the Americas (Board of Trustees, RBG Kew 2019). It is not listed as occurring in the UAE by Plants of the World Online, and is also considered doubtful for Oman.

This species is recently reported for the UAE, with records from Fujairah (Wadi Ham dam), Ras Al Khaimah (Wadi Al Qowr dam, Wadi Al Mansab dam, Wadi Al Mudaynah dam, Wadi Shawkah dam, Wadi Al Qasheesh dam, and Wadi Sfini dam) (Mahmoud et al. 2016). The native range is of this species is given as tropical and subtropical Old World by Plants of the World Online (Board of Trustees, RBG Kew 2019). Mahmoud et al. (2016) give the native range as Eurasia and Africa, stating that the species has become widespread in tropical, subtropical and warm-temperate areas worldwide (El-Hamidi et al. 1967). Regionally, it has been recorded in Saudi Arabia, Oman, Yemen and Socotra, as well as the UAE (Mahmoud et al. 2016).

The species was recorded for the UAE in 1996 from an unknown locality (Böer and Eschmann-Grupe 1996), however it was long mistaken for other taxa, and it is now considered to be widespread in the mountain areas of the UAE where standing water is present. Globally, this species occurs from Africa to temperate Eurasia (Board of Trustees, RBG Kew 2019). According to Plants of the World Online, this species is not native to the UAE (Board of Trustees, RBG Kew 2019). The UAE is also not listed as a country of occurrence on the most recent Red List Assessment for this species (Mani 2014).

In the UAE, the species along central and eastern parts of the Arabian Gulf coast, including offshore islands, along the east coast, and from Jebel Hafeet (Jongbloed et al. 2003). The species also occurs in inland saline marshes (MEW 2010) and in irrigated areas within urban areas (Perry 2008). This is a Mediterraneo-Touranian (Mediterranean basin and Iran) species. It is widespread from West Africa to Central Asia and the Indian subcontinent; also found in southern parts of Europe, including Sicily, Karpathos, Crete, Cyprus and Malta.

The species is common and widespread in the Hajar Mountains in eastern UAE (Jongbloed et al. 2003). Feulner (2011) records the species from a single native site ('Ayn as-Sih, wadi al-'Ayn) in the Ru'us al-Jibal, however this locality is in Oman. The species is also considered native to Abu Dhabi Emirate (S. Sakkir pers. comm. 2018), but the distribution there is uncertain, and its use as an ornamental plant in Abu Dhabi city is also reported. The species is listed as an introduced plant by MoCCaE (O. Al Shamsi pers. comm. 2019) and Al Mehairbi et al. (2019). The species is considered to be native from West and Central Asia to temperate East Asia, although only the 'Gulf States' is referred to, not the UAE specifically (Board of Trustees, RBG Kew 2019). GRIN (2019) cite only Saudi Arabia in the Arabian Peninsula; the true native distribution is obscure (CABI 2019).

Within the UAE, this species has been recorded from Abu Dhabi and Digdaga, in addition to along the Dibba to Khor Fakkan road (Jongbloed et al. 2003) and in Hatta. It is suggested to have a very localised distribution along the east coast, although G. Feulner does not know this species from this area (G. Feulner pers. comm. 2019). Its maximum EOO was initially estimated to be 2,709 km² when including a locality at Ras al-Khaimah, however, when excluding this locality (as this species presence is currently uncertain here), the EOO estimate is 812 km². There are considered to be less than ten locations according to the major threats to this species. Its native range spans across the temperate northern hemisphere in addition to South America (Board of Trustees, RBG Kew 2019).

The origin and distribution of this species in the UAE requires confirmation. The species is only listed, without details, in Jongbloed et al. (2003), while G.R. Feulner (in lit. MEW 2010) comments that the species is not found in natural wetland sites (e.g. wadi pools) in the UAE, only in dam reservoirs, scrapes, and in artificial ponds. Globally, this species is native to Africa, the Mediterranean, the Arabian Peninsula and Iran (Board of Trustees, RBG Kew 2019). Whilst Plants of the World Online includes the UAE in the global distribution of the species, the current global assessment of this species excludes the UAE, only including Yemen within the Arabian Peninsula.

Within the UAE, it has been recorded from the dam at Khor Fakkan, in the Emirate of Fujairah (Böer and Chaudhary 1999). It is also known from dams in Hatta and Al Manama. In the Arabian Peninsula, it occurs in other countries including Saudi Arabia (Chaudhary 2001), Oman (Miller and Morris 1988), Yemen (Wood 1997) and Socotra (Miller and Morris 2004), however, the draft Red List assessment of this species for the Arabian Peninsula (A. Patzelt and S.G. Knees) does not list the UAE in its distribution, and the origin of the species in the UAE requires confirmation, given its occurrence in anthropogenic sites. Globally, this species is widespread across cosmopolitan areas of North and South America, Europe, Asia, Africa and Australasia (Board of Trustees, RBG Kew 2019).

Within the UAE, Jongbloed et al. (2003) reported this species from a small number of scattered locations in the eastern UAE (Abu Dhabi, Al Ain, Ras al Khaimah). Survey data from the Sharjah Seedbank & Herbarium show additional scattered records (Hatta, coastal Ras al-Khaimah and eastern Sharjah). Feulner (2016) reported this species from Wadi Wurayah National Park (pools at the base of the Wadi Wurayah waterfall and along the wadi above), an area that is intensively used by tourists; the origin of the species here requires confirmation. The species has an enormous global distribution in temperate and subtropical regions (Board of Trustees, RBG Kew 2018).

This species was first described for the UAE (Wadi Bih, Ras Al Khaimah) in 1999 (Böer and Chaudhary 1999) but a specimen was actually collected earlier, in 1980 (<a href=""http://data.rbge.org.uk/herb/E00361435"">RBG Edinburgh Herbarium</a>: ""Jabal Ruwaydah, at head of Wadi Sidakh; north-facing limestone hillside, 500 m""). The native range is Greece, the southern and eastern Mediterranean, through the Arabian Peninsula, to southern central China (Board of Trustees, RBG Kew 2019).