Desmidorchis flava occurs in Wadi Farfar, Wadi Sfai and Wadi Sahm (Olive Highlands) within the Hajar Mountains (Jongbloed et al. 2003, Feulner 2014, D. Aplin pers. comm. 2019). The estimated extent of occurrence (EOO) for this species 261 km². It is also known from Jebel Ghaweel in Oman. Globally this species occurs in Yemen, Oman, the UAE and Qatar (Board of Trustees, RBG Kew 2018).

This species occurs among rocks in the Hajar Mountains including the Wadi Wurayah National Park (Feulner 2016) and the Ru'us al-Jibal (Jongbloed et al. 2003, Feulner 2011, Gairola et al. 2017). It is considered to be widespread within this area (Feulner 2011). Typically, this species can be encountered at moderate elevations (Feulner 2011). Globally, this species occurs on the Arabian Peninsula (Board of Trustees, RBG Kew 2018).

This species occurs in the East of the country, especially on alluvial plains of the southern Hajar mountains (Jongbloed et al. 2003). It has been recorded in the Wadi Wurayah National Park (Feulner 2016) and also once in Ru'us al-Jibal mountains (Feulner 2011). Globally, this species occurs in the Middle East, Central Asia and India (Board of Trustees, RBG Kew 2019).

Within the UAE it has been recorded from the Hatta area, in the northeast of the country (Böer and Chaudhary 1999). Globally, the native range of this species spans from Hungary to Somalia and the western Himalayas (Board of Trustees, RBG Kew 2019).

There is little information available for this species in terms of distribution in the UAE, however, Tamarix aucheriana is considered to occur in saline areas within the country. Globally, this species is native to northern Africa and temperate Asia (Board of Trustees, RBG Kew 2019). Plants of the World Online doesn't list the UAE as a native country of occurrence for this species, and Norton et al. (2009) state that this species is not found in other Gulf States except for Qatar.

In the UAE, this species is widespread across the eastern half of the UAE, north of the Abu Dhabi-Al Ain road, although it is less common in the mountains (Jongbloed et al. 2003). It occurs in Jebel Hafeet (Wadi Tarabat; Sakkir and Brown 2014). The global range of this species is across northern and central parts of Africa, through the Arabian Peninsula to India (Board of Trustees, RBG Kew 2019). Plants of the World Online also lists occurrence in Ecuador as native.

In the UAE, this species was collected by M. Jongbloed from along the Dubai-Al Ain road (Jongbloed et al. 2003). The draft Red Data Book (MEW 2010) considered that all material identified as T. megistopterus is referable to T. pentandrus. Plants of the World Online (Board of Trustees, RBG Kew 2019) considers the species to be endemic to the Arabian Peninsula (Gulf States and Oman), whilst the African Plant Database (AFD 2019) considers it to also be present in north-east Africa.

The species was recorded for the UAE (as Tribulus bimucronatus var. inermis) by Böer and Chaudhary (1999) from the from the hills near Dibba, and the identity of the record requires confirmation. The global range of this species spans from north Africa (Morocco) and north-east Africa, through to the Arabian Peninsula (Saudi Arabia, Yemen, Qatar and the UAE; Board of Trustees, RBG Kew 2019).

Within the UAE, it is common and widespread throughout inland sandy regions across the entire country (Jongbloed et al. 2003). Globally, this species is native to countries within the Arabian Peninsula (Board of Trustees, RBG Kew 2019). According to the outcome of the UAE National Red List Workshop (15th-19th September 2019, Dubai), records of Tribulus omanense within the UAE are considered within Tribulus arabicus. This is due to the species material for T. omanense being described a year after T. arabicus by Hadidi, despite the identification appearing to use the same type material. T. omanense was described as occurring throughout the south of the UAE, in sandy areas.

Western (1991) considered this species to mostly occur in the Western Region bordering Qatar and Saudi Arabia, whilst MEW (2010) considered the species to be widespread along the Arabian Gulf coast and on sandy and gravelly plains in the northern Emirates. Jongbloed et al. (2003) show a coastal distribution in western and central areas, but extending inland to Jebel Hafeet and east to the east coast of the UAE. According to comments from the UAE National Red List Workshop (15^th-19^th September 2019, Dubai), here, we consider T. qatarensis to have a coastal distribution in addition to being a separate species to T. mandavillei and T. hamiensis. The species has been recorded for Jebel Hafeet (Stuart and Stuart 1998), however Brown et al. (2007) considered the subpopulation there to be distinct, as Zygophyllum cf. migahadii; Feulner (2014) considered the species present on Jebel Hafeet to be T. migahadii, but T. qatarensis to be present to the base of the mountain. Alzahrani and Albokhari (2017, 2018) give the global distribution as Saudi Arabia (eastern region and north-central areas), Qatar, Kuwait, Bahrain, United Arab Emirates, Oman, Socotra, Yemen and Iraq.