This is the most common species of seagrass in the UAE. In the Arabian Gulf, there are large areas of this species in inshore areas and around most, if not all, islands in Abu Dhabi Emirate, from the Abu Dhabi Islands to Ra's Hanjurah, with a total area of c.55 km² estimated and representing c. 60% of seagrass bed content (EAD 2017); seagrass was found to be much more abundant in eastern Abu Dhabi, with the highest densities occurring north of Abu Dhabi Island around Al Samaliyah Island (EAD 2008). There is estimated to be around 4,000 km² of this species within Abu Dhabi Emirate (H.S. Das pers. comm. 2019). The species also occurs in Dubai Emirate, with records of extensive seagrass beds containing this species in the Jebel Ali area, particularly between Ras Hasyan and Ras Ghantoot, with their distribution primarily linked to areas of unconsolidated, deep sand (CBD 2016), and offshore from Jumeirah Beach. The species occurs eastwards to at least Umm Al Quwain. This species has a wide Indo-Pacific distribution. In the Pacific, it is found in southern Japan, Taiwan, the Philippines, Malaysia, Indonesia, throughout the Gulf of Thailand and along the coast of Vietnam and southern China. It occurs throughout insular Southeast Asia, northeast to the Northern Mariana Islands, Micronesia, and southeast to the Fiji Islands, as well as across northern Australia and the Great Barrier Reef. In the Indian Ocean, it is found from Geographe Bay in Western Australia extending across the Timor Sea, the south coast of Indonesia, and to the Andaman Sea and extending around the Bay of Bengal and around India to the Malabar Coast. It ranges from the Persian Gulf to the Red Sea, south to the east coast of South Africa to Madagascar and the islands of the western Indian Ocean.

Within the UAE, this species has been recently recorded from the Ru'us al-Jibal (Feulner 2011). It is thought to generally grow at high elevations within this area, between 1,200 and 1,350 m (Feulner 2011). Globally, this species' native range spans from Tunisia to Afghanistan (Board of Trustees, RBG Kew 2019).

This species is known from the Ru'us al-Jibal and from the Al Ain area (Jongbloed et al. 2003, Feulner 2011). It has been reported from elevations between sea level to around 800 m (Gupta 2013). Globally, this species is native to the Arabian Peninsula, India and the surrounding countries: Southeast Asia, Indonesia and northern Australia (Board of Trustees, RBG Kew 2018). It has been introduced to eastern Africa, Central America and northern South America (Board of Trustees, RBG Kew 2018).

This species has been recorded from the Ru'us al Jibal (Wadi Beh; Böer and Chaudhary 1999) and from the Hatta Hills in the Hajar Mountains, where it is rare (MEW 2010), and from the 'Olive Highlands' area (Feulner 2014). Chamberlain (1996): Recorded from Saudi Arabia and Yemen (N & S) but no specimens have been seen. Distributed widely across the temperate parts of Eurasia and northern Africa and introduced in America and Australia.

This is an occasional species that is found near groundwater in wadis or springs in the Hajar Mountains in the eastern UAE (Jongbloed et al. 2003). It is more common in the Hajar Mountains than in the Ru'us al-Jibal, where it is known from a single site ('Ayn as-Sih; Feulner 2011) in Oman. This plant species has a cosmopolitan global distribution (Board of Trustees, RBG Kew 2018).

Within the UAE, it is known to occur in Al Ain, Abu Dhabi, R'as al-Khaimah and Fujairah (Böer and Saenger 2006, Karim and Dakheel 2006). It has also been recorded from offshore islands of Abu Dhabi (Sakkir et al. 2017). Al Mehairbi et al. (2019) show its presence through the Hajar Mountains and in scattered localities, including in and around Abu Dhabi city, but do not show presence on the islands. The species is listed as an introduced landscape plant by MoCCaE (O. Al Shamsi pers. comm. 2018). Globally, the native range of this species spans across temperate, subtropical and tropical mountain areas (Board of Trustees, RBG Kew 2019).

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.

Within the UAE, this species occurs in coastal areas (Jongbloed et al. 2003), with the first record from Ras al-Khaimah beach (Böer and Chaudhary 1999). Brown and Sakkir (2004) report the species from Abu Dhabi Emirate, without details, and it is also known from plantations along the Fujairah coast. This is a circum-Mediterranean species, with a very wide biogeographical distribution that covers southern Europe, western Asia, North Africa and extends from the Arabian Peninsula to India (Euro+Med Plantbase 2006-2010). In the Mediterranean region it is very widespread, occurring in Spain, the Balearic Islands, France, Italy, Sicily, Sardinia, Croatia, former Yugoslavia, Albania, Greece (including Crete and the East Aegean Islands), Bulgaria, Turkey, Cyprus, Syria, Lebanon, Israel, Palestine, Jordan, Morocco, Algeria, Tunisia, Libya and Egypt.

This species occurs along both the western and eastern coastal areas of the UAE (Jongbloed et al. 2003, Al Meharibi et al. 2019) and in the Hajar Mountains (Feulner 2011). Western (1983) reported the species from across Abu Dhabi Island; Western found it in the outfall of a sewage treatment works, so it may persist in anthropogenic habitats, and presence on the island is shown by Al Meharibi et al. (2019). Globally this species occurs in North and East Africa, southern Europe north to the UK, around the Mediterranean basin, to Central and East Asia. It has been introduced to the Americas, southern Africa and to Oceania (Board of Trustees, RBG Kew 2018).