Central province, Saudi Arabia

Flora of Riyadh - Central Province

The central region or the 'Najd' is characterized by hillocks, valleys (wadis), meadows ('raudhas'), salt pans('sabkhas'), gravel ('reg'), rocky ('hammada') and sandy deserts. The entire area is a large plateau which lies within a low precipitation area, often receive less than 100mm rain. An array of hillocks and notably the arch-shaped Tuwayq Mountain range (c. 1000m) that stretches about 800 km along the central region is the main landmark of this Province. Several wadis also present in the region. Among these Wadi Hanifa is the prominent one running for a length of about 100 km from north to south direction, passing along the western sides of Riyadh City. The area is devoid of any perennial streams, although there are a few underground aquifiers exist in the southern part of Riyadh.
Huge areas of sand dunes (mostly the extensions of Dahna sands) are present in the northern, eastern and southern borders. Isolated longitudinal dunes of 100km or more in length occur along the middle and western edges. The entire area fall within the Saharo-Arabian (Saharo-Sindian in a broad sense) phytochorion and therefore the vegetation is mainly dominated by annuals and drought resistant xeromorphs. Vegetation of rocky deserts are generally sparse due to the impermeability of water and its impenetrable surface to plant roots. Plant growth and seed deposits are largely confined to the periphery of the gravel areas, where fine soil accumulate over a considerable period and generate a habitat conducive for certain shallow rooted plants. Plateau and other deserts are also less favourable for plant growth due to exposure to wind and other evaporating factors. Vegetation in such areas are restricted to notches and crevices. Vegetation is virtually nil on hillocks except for a few grass species and some perennial plants. However the west facing slopes hold significant number of annuals and perennials. Wadis on the other hand, which receive additional supply of runoff water along with fine soil from the elevated places, are the real seat of the main vegetation. Acacias are the dominant group in such wadis. In depressions where the soil is composed of loam and silt, the vegetation is dominated by annuals. There are several raudhas in the region, most of which are located near sand dunes and are influenced by the vegetations of both sand-dunes and rocky habitats. Tree species are rare in the central region. Out of 70 tree species present in Saudi Arabia, the central region contains only Acacia gerrardii and A. raddiana, in wadis and a few stands of Ziziphus spina-christi, Maerua crassifolia, Moringa peregrina, Capparis decidua and Ficus palmata in open plains or in gullies or ravines of hilly areas. Common plants of some of the major habitats of the central region are as follows:
Valley (Wadi) Acacia gerrardii Acacia ehrenbergiana Acacia tottilis Lycium shawii Aizoon canariense Blepharis ciliaris Amaranthus viridis Arnebia hispidissima Alkanna orientalis Atriplex leucoclada Conyza bonariensis Xanthium strumarium Tripleurospermum auriculatum Convolvulus glomeratus Convolvulus oxyphyllus ssp. oxycladus Brassica tournefortii Zilla spinosa Cucumis prophetarum Stipa capensis Trigonella hamosa Cistanche phelypaea Rumex vesicarius Haplophyllum tuberculatum Scrophularia deserti Teucrium oliverianum Fagonia indica Tribulus terrestris Peganum harmala Calotropis procera Raudhats (Meadow) Amaranthus graecizans Asphodelus tenuifolius Arnebia hispidissima Lappula spinocarpos Heliotropium arbainense Bassia eriophora Chenopodium murale Anthemis deserti Achillea fragrantissima Calendula arvensis Centaurea pseudosinaica Filago desertorum Ifloga spicata Scorzonera intricata Zoegea purpurea Aaronsohnia factorovskyi Urospermum picroides Sonchus oleraceus Reichardia tingitana Convolvulus arvensis Sisymbrium irio Notoceras bicorne Cenchrus ciliaris Lolium rigidum Hordeum murinum Phalaris minor Schismus barbatus Trigonella anguina Trigonella hamosa Trigonella stellata Spergula fallax Astragalus corrugatus Medicago laciniata Malva parviflora Tripleurospermum auriculatum Open Plains (Plateau) Heliotropium bacciferum Trichodesma africanum Agriophyllum minus Bassia muricata Halothamnus bottae Cornulaca monocantha Helianthemum lippii Salsola imbricata Asteriscus heirochunticus Pulicaria jaubertii Scorzonera musillii Convolvulus pilosellifolius Convolvulus oxyphyllus ssp. oxycladus Ochradenus baccatus Farsetia aegyptiaca Moricandia sinaica Morettia parviflora Diplotaxis harra Erucaria hispanica Capsella bursa-pastoris Citrullus colocynthis Chrozophora oblongifolia Cenchrus ciliaris Pennisetum divisum Panicum turgidum Senna italica (Cassia italica) Rumex dentatus Fagonia bruguieri Sabkhah (Salt Pans) Anabasis setifera Halopeplis perfoliata Traganum nudatum Suaeda aegyptiaca Aeluropus lagopoides Tamarix nilotica Zygophyllum simplex Zygophyllum coccineum Juncus rigidus Cressa cretica Capparis spinosa Arthrocnemum macrostachyum Salicornia europaea Cyperus laevigatus Citrullus colocynthis Cleome amblyocarpa Fagonia bruguieri Peganum harmala Phragmites australis Imperata cylindrica Leptochloa fusca Sand Dunes Moltkiopsis ciliata Centropodia forsskalii Centropodia fragilis Cakile arabica Savignya parviflora Calligonum comosum Artemisia monosperma Cyperus conglomerates Stipagrostis drarii Plantago boissieri Plantago psammophila Scrophularia hypercifolia Silene villosa Savignya parviflora Plantago ciliata Stipagrostis plumosa Haloxylon persicum Anthemis deserti Astragalus schimperi Dipterygium glaucum Eremobium aegyptium Sporobolus spicatus Mountains Periploca aphylla Capparis cartilaginea Echinops spinosissimus Erodium deserti Lasiurus scindicus Erodium glaucophyllum Schimpera arabica Avena fatua Isatis lusitanica Brachypodium distachyum Hordeum murinum Hyparrhenia hirta Tetrapogon villosus Lavandula pubescens Salvia aegyptiaca Teucrium polium Plantago amplexicaulis Emex spinosa Caylusea hexagyna Ochradenus baccatus Themeda triandra		Mimosaceae Mimosaceae Mimosaceae Solanaceae Aizoaceae Acanthaceae Amaranthaceae Boraginaceae Boraginaceae Chenopodiaceae Compositae Compositae Compositae Convolvulaceae Convolvulaceae Cruciferae Cruciferae Cucurbitaceae Gramineae Leguminosae Orobanchaceae Polygonaceae Rutaceae Scrophulariaceae Labiatae Zygophyllaceae Zygophyllaceae Zygophyllaceae Asclepiadaceae Amaranthaceae Asphodelaceae Boraginaceae Boraginaceae Boraginaceae Chenopodiaceae Chenopodiaceae Compositae Compositae Compositae Compositae Compositae Compositae Compositae Compositae Compositae Compositae Compositae Compositae Convolvulaceae Cruciferae Cruciferae Gramineae Gramineae Gramineae Gramineae Cruciferae Papilionaceae Papilionaceae Papilionaceae Papilionaceae Papilionaceae Papilionaceae Malvaceae Asteraceae Boraginaceae Boraginaceae Chenopodiaceae Chenopodiaceae Chenopodiaceae Chenopodiaceae Cistaceae Chenopodiaceae Asteraceae Asteraceae Asteraceae Convolvulaceae Convolvulaceae Resedaceae Brassicaceae Brassicaceae Brassicaceae Brassicaceae Brassicaceae Brassicaceae Cucurbitaceae Euphorbiaceae Poaceae Poaceae Poaceae Caesalpiniaceae Polygonaceae Zygophyllaceae Chenopodiaceae Chenopodiaceae Chenopodiaceae Chenopodiaceae Gramineae Tamaricaceae Zygophyllaceae Zygophyllaceae Juncaceae Convolvulaceae Capparaceae Chenopodiaceae Chenopodiaceae Cyperaceae Cucurbitaceae Capparaceae Zygophyllaceae Zygophyllaceae Gramineae Gramineae Gramineae Boraginaceae Poaceae Poaceae Brassicaceae Brassicaceae Polygonaceae Asteraceae Cyperaceae Poaceae Plantaginaceae Plantaginaceae Scrophulariaceae Caryophyllaceae Brassicaceae Plantaginaceae Poaceae Chenopodiaceae Asteraceae Papilionaceae Capparaceae Brassicaceae Poaceae Asclepiadaceae Capparaceae Asteraceae Geraniaceae Poaceae Geraniaceae Brassicaceae Poaceae Brassicaceae Poaceae Poaceae Poaceae Poaceae Lamiaceae Lamiaceae Lamiaceae Plantaginaceae Polygonaceae Resedaceae Resedaceae Poaceae		*Acacia ehrenbergiana* *Rhanterium epapposum* *Lycium shawii* Cenchrus ciliaris
Flora of the Central Region (Riyadh and Qassim Provinces). A provisional list of species of the Central Region ACANTHACEAE Blepharis ciliaris AIZOACEAE Aizoon canariense Aizoon hispanicum Sesuvium sesuvioides Zaleya pentandra AMARANTHACEAE Aerva javanica Amaranthus albus Amaranthus graecizans Amaranthus hybridus Arnaranthus lividus Amaranthus viridis AMARYLLIDACEAE Pancratium tortuosum ANACARDIACEAE Rhus tripartita APOCYNACEAE Rhazya stricta ASCLEPIADACEAE Calotropis procera Glossonema varians Gomphocarpus fruticosus Gomphocarpus sinaicus Leptadenia pyrotechnica Odontanthera radians Pergularia tomentosa Periploca aphylla ASPHODELACEAE Asphodelus tenufolius Asphodelus refractus BORAGINACEAE Alkanna orientalis Anchusa aegyptiaca Anchusa italica Anchusa milleri Arnebia decumbens Arnebia hispidissima Arnebia linearifolia Arnebia tinctoria Echium arabicum Gastrocotyle hispida Heliotropium aegyptiacum Heliotropium arbainense Heliotropium bacciferum Heliotropium curassavicum Heliotropium digynum Heliotropium strigosum Lappula sinaica Moltkiopsis ciliata Trichodesma africanum var. africanum CAPPARACEAE Capparis decidua Capparis sinaica Capparis spinosa Cleome amblyocarpa Cleome arabica Cleome gynandra Cleome noeana Cleome noeana ssp. brachystyla Cleome rupicola Dipterygium glaucum Maerua crassifolia CARYOPHYLLACEAE Arenaria foliacea Arenaria serpyllfolia Cometes surattensis Dianthus deserti Gymnocarpos decander Gypsophila capillaris Herniaria hirsuta Loeflingia hispanica Paronychia arabica Polycarpaea repens Polycarpaea robbairea Pteranthus dichotomus Silene apetala Silene arabica Silene colorata var. oliveriana Silene conoidea Silene villosa Spergula fallax Spergularia bocconei Spergularia diandra Spergularia marina Stellaria media CERATOPHYLLACEAE Ceratophyllum demersum CHENOPODIACEAE Agathophora alopeuroides Anabasis lachnantha Agriophyllum minus Anabasis setifera Arthrocnemum macrostachyum Atriplex dimorphostegia Atriplex leucoclada var. inamoena Bassia arabica Bassia eriophora Bassia indica Bassia muricata Beta vulgaris ssp. maritima Chenopodium album Chenopodium ambrosioides Chenopodium murale Chenopodium opulifolium Chenopodium praetericola Cornulaca aucheri Cornulaca ehrenbergii Halocharis sulphurea Halopeplis perfoliata Halothamnus bottae Halothamnus iraqensis Haloxylon persicum Haloxylon salicornicum Noaea mucronata Salicornia europaea Salsola cyclophylla Salsola imbricata Salsola jordanicola Salsola schweinfurthii Salsola spinescens Salsola tetrandra Salsola villosa Salsola volkensii Seidlitzia rosmarinus Suaeda aegyptiaca Suaeda vermiculata Traganum nudatum CISTACEAE Helianthemum kahiricum Helianthemum ledifolium Helianthemum lippii Helianthemum salicifolium Helianthemum sessilflorum COMMELINACEAE Commelina africana COMPOSITAE Aaronsohnia factorovskyi Achillea fragrantissima Anthemis deserti Anthemis pseudocotula Anthemis scrobicularis Anvillea garcinii Artemisia judaica Artemisia monosperma Artemisia sieberi Asteriscus graveolens Asteriscus hierochunticus Atractylis cancellata Atractylis carduus Bidens biternata Blumea bovei Calendula arvensis Carthamus nitidus Centaurea pseudosinaica Conyza bonariensis Echinops erinaceus Echinops mandavillei Eclipta alba Filago desertorum Flaveria trinervia Gymnarrhena micrantha Ifloga spicata Koelpinia linearis Lactuca dissecta Lactuca inermis Lactuca sp. aff. sativa Launaea angustfolia Launaea capitata Launaea mucronata Launaea nudicaulis Launaea procumbens Leontodon laciniatus Matricaria aurea Picris cyanocarpa Picris radicata Pulicaria arabica Pulicaria crispa Pulicaria glutinosa Pulicaria jaubertii Reichardia tingitana Rhanterium epapposum Scorzonera intricata Scorzonera musilii Scorzonera tortuosissima Senecio flavus Senecio glaucus Sonchus oleraceus Symphyotrichum squamatum Tripleurospermum auriculatum Urospermum picroides Verbesina encelioides Xanthium strumarium Zoegea purpurea CON VOLVULACEAE Convolvulus arvensis Convolvulus austroaegyptiacus Convolvulus buschiricus Convolvulus fatmensis Convolvulus glomeratus Convolvulus infantispinosus Convolvulus oxyphyllus ssp. oxycladus Convolvulus pilosellifolius Convolvulus prostratus Cressa cretica Cuscuta campestris Cuscuta pedicellata Cuscuta planiflora Ipomoea aquatica Ipomoea cairica CRUCIFERAE Anastatica hierochuntica Brassica juncea Brassica oleracea Brassica rapa Brassica tournefortii Cakile arabica Capsella bursa-pastoris Carrichtera annua Coronopus didymus Diplotaxis acris Diplotaxis erucoides Diplotaxis harra Eremobium aegyptiacum ssp. lineare Eruca sativa Erucaria hispanica Farsetia aegyptia Farsetia burtoniae Farsetia linearis Horwoodia dicksoniae Isatis lusitanica Lepidium aucheri Lepidium draba Lepidium sativum Malcolmia africana Matthiolta longipetala Morettia canescens Morettia parviflora Notoceras bicorne Raphanus sativus Savignya parvtflora Schimpera arabica Schouwia purpurea Sinapis arvensis Sisymbrium erysimoides Sisymbrium irio Zilla spinosa CUCURBITACEAE Citrullus colocynthis Cucumis prophetarum CYNOMORIACEAE Cynomorium coccineum CYPERACEAE Cyperus alternfolius ssp. flabelliformis Cyperus conglomeratus Cyperus laevigatus Cyperus rotundus Schoenus nigricans DIPSACACEAE Scabiosa olivieri Scabiosa palaestina EPHEDRACEAE Ephedra alata Ephedra foliata EUPHORBIACEAE Andrachne aspera Chrozophora oblongifolia Chrozophora tinctoria Euphorbia dracunculoides Euphorbia granulata Euphorbia hirta Euphorbia peplus Ricinus communis FRANKENIACEAE Frankenia pulverulenta GERANIACEAF Erodium cicutarium Erodium glaucophyllum Erodium laciniatum Erodium pulverulentum Monsonia nivea GRAMINEAE Aegilops kotschyi Aeluropus lagopoides Aristida adscensionis Arundo donax Avena fatua Brachiaria deflexa Brachypodium distachyum Bromus spp. Centropodia forsskalii Centropodia fragilis Cutandia memphitica Cynodon dactylon Dactyloctenium aegyptium Danthoniopsis barbata Desmostachya bipinnata Dichanthium annulatum Echinochloa colona Enneapogon desvauxii Eragrostis barrelieri Eragrostis cilianensis Eragrostis ciliaris Hyparrhenia hirta Imperata cylindrica Lasiurus scindicus Leptochloa fusca Lolium rigidum Lolium temulentum Ochthochloa compressa Oropetium capense Panicum antidotale Panicum coloratum Panicum repens Panicum turgidum Paspalidium desertorum Paspatum vaginatum Pennisetum divisum Pennisetum setaceum Schismus arabicus Schismus barbatus Setaria plicatilis Setaria verticillata Sorghum halepense Stipa capensis Stipagrostis drarii Stipagrostis hirtigluma Stipagrostis obtusa Stipagrostis plumosa Stipagrostis raddiana Stipagrostis uniplumis Tetrapogon villosus Themeda triandra Tragus berteronianus Tragus racemosus Tricholaena teneriffae				HYACINTHACE Dipcadi erythraeum IRIDACEAE Gynandiris sisyrinchium JUNCACEAE Juncus rigidus LABIATAE Ajuga arabica Ballota undulata Lavandula coronopifolia Lavandula pubescens Marrubium vulgare Salvia aegyptiaca Salvia deserti Salvia spinosa Teucrium oliverianum Teucrium polium Teucrium popovii LEGUMINOSAE Acacia ehrenbergiana Acacia gerrardii var. gerrardii Acacia gerrardii var. najdensis Acacia tortilis Acacia tortilis ssp. raddiana Alhagi graecorum Astragalus annularis Astragalus bombycinus Astragalus fatmensis Astragalus hamosus Astragalus kahiricus Astragalus palaestinus Astragalus sieberi Astragalus sparsus Astragalus spinosus Astragalus tribuloides Astragalus vogelii Hippocrepis constricta Hippocrepis unisiliquosa ssp. bisiliqua Indigofera spinosa Lotus halophilus Medicago laciniata Medicago laciniata var. brachyacantha Medicago minima Medicago monspeliuca Medicago orbicularis Melilotus indicus Onobrychis ptolenzaica Prosopis farcta Prosopis julflora Prosopis koelziana Retama raetam Rhynchosia minima var. minima Senna alexandrina Senna italica Senna occidentalis Taverniera aegyptiaca Tephrosia purpurea ssp. apollinea Tephrosia purpurea ssp. leptostachya var leptostachya Trifolium retusum Trigonella anguina Trigonella foenum-graecum Trigonella hamosa Trigonella stellata Vermifrux abyssinica LEMNACEAE Lemna perpusilla LILIACEAE Gagea reticulata LYTHRACEAE Lawsonia inermis MALVACEAE Althaea ludwigii Hibiscus micranthus Malva parviflora Malva verticillata Malvastrum coromadelianum Senra incana MENISPERMACEAE Cocculus pendulus MOLLUGINACEAE Gisekia pharnaceoides Glinus lotoides Limeum arabicum Limeum obovatum Mollugo cerviana MORACEAE Ficus cordata ssp. salicifo1ia Ficus palmata MORINGACEAE Moringa peregrina NEURADACEAE Neurada procumbens NYCTAGINACEAE Boerhavia elegans ssp. elegans Boerhavia elegans ssp. stenophylla OLEACEAE Jasininum grandiflorum var. floribundum ORCHIDACEAE Zeuxine strateumatica OROBANCHACEAE Cistanche phelypaea Orobanche aegyptiaca Orobanche cernua var. cernua OXALIDACEAE Oxalis corniculata PALMAE Phoenix dactylifra PAPAVERACEAE Glaucium corniculatum Hypecoum pendulum Papaver rhoeas Roemeria hybrida ssp. dodecandra PLANTAGINACEAE Plantago afra Plantago amplexicaulis Plantago amplexicaulis ssp. bauphula Plantago boissieri Plantago ciliata Plantago coronopus Plantago cylindrica Plantago lanceolata Plantago major Plantago maris-mortui Plantago ovata Plantago psammophila PLUMBAGINACEAE Limonium thounii POLYGALACEAE Polygala negevensis Polygala schwartziana POLYGONACEAE Calligonum comosum Emex spinosa Polygonum aviculare Rheum palaestinum Rumex conglomeratus Rumex dentatus Rumex pictus Rumex vesicarius PORTULACACEAE Portulaca grandiflora Portulaca oleracea POTAMOGETONACEAE Potamogeton nodosus Potamogeton pectinatus Potamogeton perfoliatus PRIMULACEAE Anagallis arvensis var. arvensis Samolus valerandi RANUNCULACEAE Adonis dentata Delphinium orientale RESEDACEAE Caylusea hexagyna Ochradenus arabicus Ochradenus baccatus Oligomeris linifolia Reseda arabica Reseda aucheri var. bracteata Reseda decursiva Reseda lutea Reseda muricata RHAMNACEAE Ziziphus nummularia Ziziphus spina-Christi var. inermis Ziziphus spina-Christi var. spina-Christi RUBIACEAE Galium aparine Kohautia caespitosa var. caespitosa Pterogaillonia calycoptera RUPPIACEAE Ruppia maritima RUTACEAE Haplophyllum tuberculatum SALVADORACEAE Salvadora persica SCROPHULARIACEAE Aptosimum pumilum Bacopa monnieri Kickxia aegyptiaca Kickxia pseudoscoparia Linaria haelava Linaria tenuis Schweinfurthia pterosperma Scrophularia deserti Scrophularia hypercifo1ia SOLANACEAE Datura innoxia Datura stramonium Hyoscyamus pusillus Lycium dasystemum Lycium shawii Solanum nigrum Solanum villosum Withania somnifera TAMARICACEAE Tamarix aucheriana Tamarix aphylla Tamarix nilotica (T. senegalensis) Tamarix passerinoides var. macrocarpa TILIACEAE Corchorus depressus Corchorus olitorius TYPHACEAE Typha domingensis UMBELLIFERAE Anisosciadium lanatum Coriandrum sativum Cuminum cyminum Deverra tortuosa Deverra triradiata ssp. musilii Ducrosia anethifolia Foeniculum vulgare Pimpinella cretica var. arabica Pycnocycla tomentosa Torilis arvensis URTICACEAF Forsskaolea tenacissima Parietaria alsinifolia Urtica pilulifera Urtica urens ZYGOPHYLLACEAE Fagonia bruguieri Fagonia glutinosa Fagonia indica Fagonia ovalifolia ssp. qatarensis Nitraria retusa Peganum harmala Seetzenia lanata Tetraena alba Tetraena coccinea Tetraena decumbens Tetraena hamiensis Tetraena mandaville Tetraena propinqua Tetraena simplex Tribulus bimucronatus Tribulus kaiseri Tribulus macropterus Tribulus macropterus var. arabicus Tribulus macropterus var. collenetteae Tribulus parvispinus Tribulus pentandrus Tribulus terrestris var. robustus Tribulus terrestris var. terrestris

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