Southern Tihama

Plant diversity in Saudi Arabia Southwestern Tihama, Saudi Arabia
Home Topography Vegetation Flora Flora check-list Northern Tihama
	Southwestern Tihama is an approximately 800 km long coastal zone stretching from Jeddah in the north to Yemen border in south. It is narrow in the north and wide in the south. Topographically the region divided into a narrow shoreline, sand dunes, open plains, wadis and hillocks. Shore line is more or less fringed with many inlets and creeks mostly holding patches of Avicennia marina population. Shallow waters in these fringes (between 1 m to 300 m away from the sea-shore) are also home to a number of sea-grasses, some of them are found in relatively deeper waters (Enhalus acoroides and Thalassia hemprichii) while others are found in shallow waters (Cymodoca rotundata, Halodule australis, Halophila ovalis, H. stipulaceae). Narrow salt pans (Sabkhas) adjacent to the shoreline is a more or less continuous and holding a scattered vegetation, dominated by Suaeda vermiculata, Zygophyllum coccineum, Halopeplis perfoliata, Sporobolus spicatus, Aeluropus lagopoides, Cressa cretica, Tamarix nilotica, Zygophyllum simplex, Desmostachya bipinnata, Cyperus conglomeratus, etc. Northern part (Al-Birk, Quinfudah, Al-Lith) of the southern Tihama is narrow due to the projection of the crystalline basement to the west, at places, particularly in Qahama area, it reaches to the sea shore. Most of the coastal sides in this part of Tihama are steep. Vegetation in these areas are very significant. However, the plains composed of stones and pebbles are dominated by Limonium axillare, Panicum turgidum, Leptadenia pyrotechnica and Pennisetum divisum whereas in areas with more saline soil, the vegetation is dominated by Suaeda monoica, Halopeplis perfoliata and Salsola spinescens. Dunes and plains constitute some of the major land-forms in Tihama. Sand Dunes in the area are formed by the deposition of silt brought in by the flash floods and subsequent piling up of sand by wind. Major vegetation components of small dunes and plains are Acacia tortilis, A. ehrenbergiana, Suaeda monoica, Leptadenia pyrotechnica, Salvadora persica, Panicum turgidum, Pennisetum divisum, and Tephrosia purpurea whereas on deep sands, the vegetation is dominated by Odyssea mucronata, Capparis decidua, Dipterygium glaucum, Cadaba rotundifolia, Halopyrum mucronatum and Indigofera argentea. Dense thickets of Salvadora persica intermixed with Acacia ehrenbergiana are also common along the less mobile undulating sand dunes. These sand dunes and adjacent plains also hold a number of ephemerals during spring, dominated mainly by Zygophyllum simplex.


Major wadis originating from the escarpments dissect through the dune formations and end in the Red Sea. Over 20 wadis cut through the plains of Tihama coast and end in Red Sea. Among these wadis, Itwed, Baysh, Dhamad, Jazan and Khulab are considered important. These wadis account for a mean annual run off rate of 7.4m³/Sec. Wadis are generally dry for the whole year or for successive years. However, occasional spates develop during rainy days. At the point of origin of the wadis, vegetation is dominated by Acacia ehrenbergiana, Salvadora persica, Delonix elata, Tamarindus indica, Berchemia discolor, Imperata cylindrica, etc. while its adjacent areas and open plains are dominated by Hyphaene thebaica, Dobera glabra and Acacia spp. along with succulents like Caralluma retrospiciens, Sansevieria and Aloe officinalis. Along the wadi beds where there are stagnant waters the vegetation is dominated by semi aquatic plants such as Typha domingensis, Cyperus laevigatus, Phyla nodiflora, Bacopa monnieri, Eclipta alba, etc and aquatic plants such as Potamogeton nodosus, Najas gramminae, Marselia aegytiaca, etc.
		Eastern edge of Tihama region is characterized by hillocks, most of which rise from 150 to 250 m. Topography of these hillocks varies from rocky boulders to gravels with shallow runnels. Vegetation is sparse and scattered on the gentle slopes of the hills, mainly dominated by Acacia tortilis along with associated species such as Adenium obesum, Anisotes trisulcus, Acacia asak, Commiphora opobalsamum, Lycium shawii, Hibiscus micranthus, etc. Foot-hills and neighbouring plains are covered by gravels, pebbles and stones. Vegetation on these plains are also sparse, mainly inhabited by Dobera glabra, Caralluma retrospiciens, Aloe officinalis and Senna alexandrina. Climbers such as Pentropis spiralis, Ceropegia spp. and Cissus spp. are common in the plains, often seen festooned on Acacias. Most noticeable plant in this zone is the branched palm tree, Hyphaene thebaica interspersed with occasional trees like Maerua crassifolia and Ziziphus spina-christi. Flora of Southern Tihama consists of 346 species of higher plants in 68 families. Poaceae is the largest family followed by Leguminosae, Euphorbiaceae and Asteraceae.
Floristic components of the Southern Tihama
Acanthaceae Anisotes trisulcus Barleria bispinosa Barleria hochstetteri Barleria prionites Blepharis ciliaris Hypoestes forsskaolii Ruellia patula Aizoaceae Aizon canariense Zaleya pentandra Trianthema crystallina Trianthema portulacastrum Trianthema triquetra Trianthema sheilae Zaleya pentandra Aloeaceae Aloe officinalis Amaranthaceae Achyranthes aspera Aerva javanica Aerva lanata Amaranthus graecizans Amaranthus hybridus Amaranthus lividus Amaranthus sparganiocephalus Amaranthus spinosus Amaranthus viridis Celosia trigyna Digera muricata Pupalia lappacea Anacardiaceae Combretum molle Apocynaceae Adenium obesum Asclepiadaceae Calotropis procera Caralluma retrospiciens Caralluma subulata Ceropegia aristolochioides Ceropegia tihamana Cetropegia variegata Duvalia velutina Glossonema boveanum Leptadenia pyrotechnica Pentatropis nivalis Arecaceae Hyphaene thebaica Phoenix caespitosa Phoenix dactylifera Aristolochiaceae Aristolochia bracteolata Boraginaceae Arnebia hispidissima Echium rauwfolii Heliotropium ararbainense Heliotropium bacciferum Heliotropium digynum Heliotropium europaeum Heliotropium longiflorum Heliotropium pterocarpum Heliotropium zeylanicum Trichodesma africanum Brassicaceae Farsetia longisiliqua Farsetia stylosa Morettia phileana Schouwia purpurea Sisymbrium erysimoides Sisymbrium irio Asphodelaceae Asphodelus fistulosus Burseraceae Commiphora Kataf Commiphora myrrha Commiphora opoblasamum Cactaceae Opuntia dellenii Opuntia ficus-indica Campanulaceae Campanula edulis Capparaceae Cadaba glandulosa Cadaba longifolia Capparis decidua Cadaba rotundifolia Capparis spinosa Cleome brachycarpa Cleome gynandra Cleome viscosa Dipterygium glaucum Gynandropsis gynandra Maerua crassifolia Maerua oblongifolia Chenopodiaceae Chenopodium album Chenopodium fasiculosum Cornulaca ehrenbergii Suaeda aegyptiaca Suaeda monoica Suaeda vermiculata Halopeplis perfoliata Salsola spinescens Commelinaceae Commelina africana Commelina albicans Commelina forsskalei Compositae Centaurea schimperi Conyza bonariensis Conyza dioscorides Echinops sp. Eclipta alba Launaea intybacea Launaea mucronata Launaea nudicaulis Launaea procumbens Onopordon ambiguum Parthenium hysterophorus Pluchea dioscoridis Pulicaria petiolaris Pulicaria somalensis Pulicaria undulata Reichardia tingitana Sonchus oleraceus Tridax procumbens Verbesina enceolioides Xanthium strumarium Convolvulaceae Convolvulus glomeratus Convolvulus prostrates Cressa cretica Ipomoea carnea ssp. fistulosa Operculina turpethum Seddera virgata Cucurbitaceae Citrullus colocynthis Coccinea grandis Cucumis prophetarum Momordica balsamina Cymodoceaceae Cymodocea rotundata Cymodocea serrulata Halodule uninervis Cyperaceae Cyperus alternifolius ssp. flabelliformis Cyperus articulatus Cyperus conglomeratus Cyperus laevigatus Cyperus rubicundus Cyperus rotundifolius Schoenus nigricans Dracaenaceae Sansevieria ehrenbergii Euphorbiaceae Acalypha fruticosa Acalypha indica Andrachene aspera Chrozophora oblongifolia Clutia lanceolata Croton bonplandianus Euphorbia cactus Euphorbia chamaesyce Euphorbia cuneata Euphorbia granulata Euphorbia hirta Euphorbia indica Euphorbia schimperiana Jatropha curcas Jatropha glauca Jatropha pelargonifolia Phyllanthus maderaspatensis Ricinus communis Gentianaceae Enicostemma axillare Geraniaceae Geranium trilophum Pelargonium multiflorum Hydrocharitaceae Halophila ovalis Thalassia hemprichii Hypericaceae Hypericum hircinum Lamiaceae Ocimum americanum Ocimum forsskolei Otostegia fruticosa ssp. schimperi Teucrium oliverianum Leguminosae Acacia melifera Acacia abyssinica Acacia asak Acacia ehrenbergiana Acacia etbaica Acacia gerrardii Acacia laeta Acacia oerfota Acacia seyal Crotalaria microphylla Crotalaria senegalensis Cyamopsis tetragonoloba Indigofera argentea Indigofera articulata Indigofera colutea Indigofera oblongifolia Indigofera spinosa Loganychium farctum Lotus arabicus Pithecellobium dulce Prosopis juliflora Rhynchosia pulverulenta Senna alexandrina Senna italica Senna occidentalis Sesbania leptocarpa Tephrosia nubica Tephrosia purpurea Tephrosia purpurea ssp. apollinea Tephrosia Uniflora Vicia sativa Vigna aconitifolia Vigna amabensis Loganiaceae Nuxia oppositifolia		Loranthaceae Loranthus curviflorus Lythraceae Lawsonia inermis Malpighiaceae Caucanthus edulis Malvaceae Abutilon bidentatum Abutilon fruticosum Abutilon hirtum Abutilon pannosum Althaea ludwigii Hibiscus micranthus Malva parviflora Senra incana Sida ovata Meliaceae Azadirachta indica Melia azaderach Menispermaceae Cocculus pendulus Molluginaceae Corbichonia decumbens Glinus lotoides Mollugo cerviana Moraceae Ficus vasta Nyctaginaceae Boerhavia diffusa Commicarpus grandiflorus Commicarpus plumbagineus Oleaceae Jasminum grandiflorum ssp. floribundum Orchidaceae Eulophia petersii Orobanchaceae Orobanche cernua Oxalidaceae Oxalis corniculata Pandanaceae Pandanus odoratissimus Papaveraceae Argemone ochroleuca Pedaliaceae Pedalium murex Sesamum alatum Sesamum indicum Plumbaginaceae Limoniium axillare Limonium cylindrifolium Poaceae/Gramineae Aeluropus lagopoides Aeluropus massauensis Aristida adscensionis Aristida funiculata Aristida mutabilis Brachiaria deflexa Brachiaria leersioides Cenchrus ciliaris Cenchrus echinatus Cenchrus setigerus Chloris barbata Chloris virgata Chrysopogon plumulosus Cynodon dactylon Dactyloctenium aegyptium Dactyloctenium aristatum Dactyloctenium scindicum Desmostachya bipinnata Dichanthium annulatum Dichanthium foveolatum Digitaria velutina Echinochloa colona Echinochloa pyramidalis Enneapogon lophotichus Enneapogon schimperanus Eleusine africana Eragrostis barrelieri Eragrostis ciliaris Eragrostis papposa Eriochloa fatmensis Halopyrum mucronatum Hyparrhenia hirta Lasiurus scindicus Leptochloa fusca Melinis repens Ochthochloa compressa Odyssea mucronata Panicum antidotale Panicum coloratum Panicum turgidum Paspalidium desertorum Pennisetum setaceum Pennisetum villosum Phragmites australis Piptatherum olciformis Poa sinaica Saccharum spontaneum Schoenefeldia gracilis Setaria ciliaris Setaria verticillata Sorghum bicolor Sporobolus consimilis Sporobolus ioclados Sporobolus spicatus Stipagrostis hirtigluma Stipagrostis plumosa Stipagrostis plumosa Tetrapogon cenchriformis Tetrapogon tenellus Tetrapogon villosus Themeda triandra Tragus berteronianus Tragus racemosus Tricholaena teneriffae Polygalaceae Polygala erioptera Polygonaceae Rumex vesicarius Portulacaceae Portulaca oleracea Portulaca quadrifida Potamogetonaceae Potamogeton nodosus Primulaceae Anagalis arvensis Pteridophytes Cheilanthus coriacea Marselia aegyptiaca Resedaceae Ochradenus baccatus Reseda decursiva Reseda muricata Rhamnaceae Ziziphus spina-christi Rhizophoraceae Rhizophora mucronata Salvadoraceae Dobera glabra Salvadora persica Scrophulariaceae Bacopa monnieri Craterostigma pumilum Schweinfurthia pterosperma Scoparia dulcis Striga hermonthica Verbascum nubicum Solanaceae Datura ferox Datura innoxia Dataura stramonium Physalis acuminata Physalis peruviana Solanum albicaule Solanum dubium Solanum glabrata var. sepicula Solanum incanum Solanum sepicula Solanum surattense Solanum villosum Withania somnifera Tamaricaceae Tamarix aphylla Tamarix macrocarpa Tamarix nilotica Tiliaceae Corchorus depressus Corchorus olitorius Corchorus trilocularis Typhaceae Typha domingensis Typha elephatiana Urticaceae Forsskaolea tenacissima Verbenaceae Avicennia marina Chascanum marrubifolium Phyla nodiflora Vitaceae Cissus quadrangularis Cissus rotundifolius Zygophyllaceae Fagonia bruguieri Fagonia indica Tribulus parvispinus Tribulus pentandrus Tribulus terrestris Tribulus terrestris var. inermis Zygophyllum album Zygophyllum coccineum Zygophyllum hamiense Zygophyllum simplex
Written and maintained by Dr. Jacob Thomas, Dept. of Botany & Microbiology, King Saud University, Riyadh, Saudi Arabia.