Included here are deserts of the Arabian Peninsula including Rub’ al Khali, the Great Nafud, and the crescent-shaped Dahna desert, together with the Sinai Peninsula, Hadramawt, Asir and most of Yemen.

Anabasis articulata Desert Scrub

Shrublands usually dominated by Anabasis articulata occupy a variety of desert types including hammadas (i.e. landforms made up of rolling or sloping plateaus or hillsides covered with stones of various sizes) and gravel substrates. They occupy some of the most extreme deserts in this zone where annual rainfall rarely exceeds 100 mm and can be found, for example, in the Sinai, Judean, Negev and Edom deserts. Other locally dominant or sub-dominant species include Cornulaca monacantha, Gymnocarpus decander, Halogeton alopecuroides, Hammada scoparia, Notoceras bicorne, Salsola pachoi, Stipa obtusa and Thymelaea hirsuta. Associated endemic or near endemic species include Astragalus spinosa (Fabaceae), Fagonia sinaica (Zygophyllaceae), Hammada negevensis (Chenopodiaceae), Verbascum letourneuxii (Scrophulariaceae) and Zilla spinosa (Brassicaceae).

Zygophyllum dumosum Desert Scrub

These shrublands are characteristic of various hammada type terrains particularly in the mountainous parts of the Sinai, the Negev and also parts of the Judean Desert. It may be found on hammada with a fairly well developed layer of chalky-loamy soil beneath a covering of flint-stones or on hammada with rocky outcrops and poor soil. In addition to the endemic Zygophyllum dumosum (Zygophyllaceae) other characteristic species include Allium desertorum, Asparagus stipularis, Astractylis phaeolepis, Bellevalia desertorum, Colchicum tunicatum, Diplotaxis acris, Fagonia mollis, Farsetia aegyptiaca, Lappula spinocarpos, Muscari inconstrictum, Odontospermum pygmaeum, Ranunculus asiaticus var. tenuilobus, Scabiosa aucheri, Scilla hanburyi, Tetrapogon villosus, while some of the associated endemic or near endemic taxa are Plantago phaeostoma  (Plantaginaceae), Reaumuria hirtella var. palestina (Tamaricaceae) and Reseda stenostachya (Resedaceae).

Ziziphus nummularia Desert Scrub

Vegetation dominated Ziziphus nummularia is characteristic of fine textured soils (rodat) and can be seen, for example, in north and central Qatar. Other commonly associated perennials include Acacia tortilis, Corchorus depressus, Lycium shawii, Salvia aegyptiaca and Zygophyllum qatarense. Species such as Capparis spinosa, Ephedra foliata and Ochradenus buccatus are locally abundant and the latter two can be very conspicuous in some of the protected rodat. Less common is the scandent shrub Cocculus pendulus, but in certain places (e.g. Al-Karrarah and Al-Wabrah) it has been observed climbing over Ziziphus trees. After heavy rain robat areas are often flooded, but just a few weeks later a luxuriant covering of ephemeral is likely to occur. Typical species include Aizoon canariense, Althea ludwigii, Anastatica hierochuntica, Asteriscus pygmaeus, Astragalus tribuloides, Emex spinosus, Eragrostis ciliaris, Malva parvifolia, Phalaris paradoxa, Plantago amplexicaulis, Schismus barbatus, Spergula fallax, Spergularia bocconi, Trachynia distachya and Trigonella stellata. Ephemeral are also often common in the shadow of Ziziphus trees. These trees can accumulate large mounds of water-borne and wind-borne sediment, which can further protect stands of ephemerals.

Acacia tortilis Desert Scrub

Vegetation dominated by Acacia tortilis is widespread in Qatar, for example, particularly in shallow depressions. It is also found scattered on the hozoom, but absent from the sabkhas and dune fields. In the northern and central areas Zygophyllum quatarense is also prominent while in southern areas the grass Panicum turgidum is the second most prominent species. Depending on location other associated species include Astragalus tribuloides, Atractylis carduus, Convolvulus deserti, Corchorus depressus, Eleusine compressa, Eragrostis ciliaris, Fagonia bruguiera, Francoeria crispa, Glossonema edule, Heliotropium bacciferum, Herniaria hemistemon, Lotononis platycarpa, Lycium shawii, Monsonia heliotropioides, Polycarpaea repens and Stipa capensis.

Zygophyllum qatarense Desert Scrub

Zygophyllum qatarense is one of the most common plant species in its namesake area of Qatar and vegetation dominated by this species is widespread in this area. It is particularly abundant in the shallow depressions on the rocky plateau of southern Qatar, where the habitat is subject to both wind and water erosion. Here the most common associates are Acacia tortilis, Aizoon canariense, Anastatica hierochuntia, Aristida abnormis, Corchorus depressus, Euphorbia granulata, Francoeuria crispa, Glossonema edule, Helianthemum lippii, Heriaria hemistemon, Launaea capitata, Scrophularia deserti, Stipa capensis, Tribulus terrestris and Trigonella stellata. Zygophyllum qatarense is extremely tolerant of draught and high temperates, which is helped by seasonally changes in the morphology, anatomy and physiology of its leaves. It is host to two striking parasitic plants - Cistanche tubulosa (desert broomrape) of the Orobanchiaceae family and Cynomorium coccineum of the Cynomoriaceae family. The latter is or was common on the island of Malta where it is know as Maltese mushroom despite the fact that it is a flowering plant and not a fungus.

Cornulaca monacantha Dwarf Scrub

Deep sandy soils mainly deposited by wind provide the main habitat for vegetation dominated by Cornulaca monacantha. The main areas include the sand accumulations west of Umm Bab and in the long runnels adjacent to the Emirates’ Road. In the Umm Bab area the main associates include Maltkiopsis ciliata, Panicum turgidum, Stipagrostis plumosa and Zygophyllum qatarense, but in the latter area Leptadenia pyrotechnica becomes one of the main associates.

Desert Dwarf Scrub on Gypsum

In soft chalky areas fairly rich in gypsum such as parts Jebel Ataqa and Jebel Eqma (Sinai) the vegetation is characterized by sparsely often widely spaced dwarf shrubs dominated by Salsola tetrandra. In other areas, such in the Judean Desert, these chalky habitats are dominated by other dwarf shrubs, such as Chenolea arabica, Reamuria hirtella, Suaeda asphaltica, or the endemic Hammada negevensis (Chenopodiaceae). Other endemic or near endemic species associated with this habitat include Centaurea negevensis (Asterceae), Fagonia sinaica (Zygophyllaceae), Moricandia sinaica (Brassicaceae) and Nasturtiopsis arabica (Brassicaceae).

South Arabian Acacia-Commiphora Bushland

These bushlands often dominate at low altitudes. Several associated shrubs, such as Adenium arabicum, Anisotes trisulcus, Grewia tembensis, Maerua oblongifolia and Acalypha fruticosa, can also be found in abundance. Other important plants include Carissa edulis, Clutia lanceolata, Otostegia fruticosa, Ricinus communis, Rumex nervosus, Solanum incanum, Solanum schimperianum and species of Commiphora. The herbaceous flora includes Anagallis arvensis, Conyza stricta, Evolvulus alsinoides, Pennisetum setaceum, Themeda triandra and species of Chenopodium.

South Arabian Succulent Euphorbia Scrubland

These xeromorphic succulent scrublands often interspersed with xeromorphic, open grasslands, occur in a well developed belt extending from the southern Asir and Yemen highlands eastward into the uplands of the Habramawt. The vegetation is typically dominated by various succulent Euphorbias, although their species composition varies according factors such as altitude and degree of exposure. The main species include several endemics or near endemics such as Euphorbia ammak, E. balsamifera subsp. adenensis, E. fruticosa, E. hadramautica, E. inarticulata and E. parciramulosa (Euphorbiaceae). Associated characteristic succulents include Kleinia odora and Sarcostemma viminale (Asteraceae), and various endemic species like Aloe yemenica (Liliaceae), Caralluma cicatricosa and Ceropegia rupicola (Asclepiadaceae). A number of succulent climbers of the genus Cissus (Vitaceae) may be present, and strange pachycaulous trees like Adenium obesum (Apocynaceae) and Adenia venenata (Passifloraceae). Other associated endemic or near endemic species includes Caralluma plicatiloba (Asclepiadaceae), Dracaena serrulata (Dracaenaceae) and Endostemmon tereticaulis (Lamiaceae).

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