Hail       

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Topography

              The Hail (Hayil) region of Saudi Arabia, located between 250 35` and 290 00` N longitudes and 390 01` and 440 45` E latitudes, is an exposed complex of Precambrian igneous and metamorphic rocks. It is also a part of the vast phanerozoic formations that overlap the northern and eastern edge of the Arabian Shield.  The Hail region covers an area of 118,322 sq. km (= 445,684 sq. miles). It is named after the large Wadi Hail (formerly called Al-Odair valley) in the Shammar Mountain region and is bordered in the north by Al-Jauf and Northern Frontier Emirates, to the west by Tabuk and Medina Al-Munawarra regions, to the south by Qassim Province and to the east by Central and Eastern Provinces. The study area is characterized by several landscape units, such as isolated mountains, peneplains, escarpments, wadis and sand-seas. The Hail valley extends to the north-east through a narrower corridor linking the capital city with the Shamrah Mountain, whereas the Great Nafud desert with rolling sand dunes forms northern part of the Hail region.

 

The Shammar Mountains form a major feature of Hail region and consist of two great mountain ranges namely Aja, made up of granite and Salma composed of basalt. The entire region is about 1000 m high and the height of the mountains varies from 100-600 m. Jabal Aja which is situated between Hail town and the An Nafud desert is the largest mountain in the study area.  The principal part of Hail is An-Nafud desert, which covers about 64,000 sq. km and is composed of reddish sand and lies at an elevation of 900 m from sea level. The sands are stained red because of the iron oxide coating on the sand grains. The desert is believed to be the product of Quaternary episodes of increased Aeolian activity and is composed of 60-120 m high barchanoid and transverse dunes. Major parts of the desert are formed of sand dunes. However, interdunal depressions can also be observed with relatively thin sand cover. An-Nafud, the second largest desert in the Arabian Peninsula, is connected to the largest Arabian Desert known as Rub’a al Khali (the Empty Quarter) by Ad-Dahna belt which is separating the central Najd from Eastern Arabia.

            Hail Region was reported to be a relatively excellent area for pasturage. Over the years, due to intense grazing and unsustainable use of the region's resources, the area has changed into a less productive one with a few shrubs and trees (mainly Acacias) in wadis and foothills. However, the region's mountains housed a number of endemic and rare species, some of which are not present in any other part of Saudi Arabia.

 

Climate

             The weather system in the Hail Region is generally arid to extra arid. It is influenced by two main pressures, namely Siberian high in winter and tropical low in summer months. It is also influenced by Saudi Arabia’s unique topography; mountains in the west bordering the Red Sea and desert land in the interior (Najd) eastwards. The sun-rays, as in other parts of Saudi Arabia, are intense and seldom diffused by clouds. Summer temperatures typically rise as high as 500 C in the day time with diurnal variation of about 250 C. Winter temperatures hover around freezing at night especially at higher altitudes although the ground occasionally freezes and daytime temperatures nearly always reach 250 C in the sun. The wind in the Hail emirate comes from the north or northwest and is a great evaporative force hence causing immense physical damage. At certain times of the year, especially during spring, the wind builds up 4-5 days severe dust storms known as ‘Shamals’ in which air is full of grit (sand + silt) to a height of hundreds of meters. The rainfall is erratic and there is no regular pattern. The main source of precipitation in the region is from the winter cyclones originating from the Mediterranean Sea and eastern Atlantic Ocean. Although most of the precipitation of this region is from winter storms, summer storms from the south western region also have a very minor share in some years. Snow fall and hail storms are also reported during the winter months.

 

Vegetation         

            It is evident from the studies that the entire sparse vegetation in the mountains  are influenced by the floras of Mediterranean countries, whereas the vegetation in the An Nafud sand seas and in the open plains and wadis are related to the floras of Saharo Arabian and Irano-Turranean phytogeographical regions. Though the vegetation of various landscape units are clearly distinguished in most places, the borders between units in certain areas (such as in the north-east and south-east of the study area) are difficult to demarcate because of overlapping. Rhus tripartita is one of the major components of the vegetation of the mountains followed by Ficus palmata. Other important perennials include Cymbapogon commutatus, Periploca aphylla, Gomphocarpus sinaicus, Pergularia tomentosa, Blepharis ciliaris and Trichodesma spp.. The east facing mountainous sides are somewhat steep and generally dovoid of any appreciable number of species. Nevertheless, species such as Rhus tripartita, Aerva javanica, Cenchrus ciliaris, Ephedra foliata and Astragalus spinosa forms into small communities in shades and crevices. The shaded areas of the mountains on the north western parts, on the other hand, have a richer floristic composition. Although the vegetation is spread over the shaded areas, majority of plants can be seen along the ravines and ditches where sand and silt accumulate during rainy season. Representative plants in these areas include: Noaea mucronata, Heliathemum kahiricum, Gymnocarpos decandrum, Ballota undulata, Silene schweinfurthia Paracaryum rugulosum, etc.

 

            At lower altitudes the terrain is composed of large boulders and gravels. Vegetation in this part is dominated by Ochradenus baccatus, Zoegea purpurea, Aerva javanica, Pennisetum setaceum, Astragalus spinosus, Teucrium polium, Lycium shawii, Fagonia indica, etc., whereas in the foothills Haloxylon salicornicum is dominant among the shrublet category, which is associated with Zilla spinosa, Rhanterium epapposum, Astragalus sieberi, etc.

 

            The wadi system in the Hail Region, in general, is part of the Wadi Rimah drainage. Acacia gerrardii is the major component dominating in these wadis, along with occasional shrubs such as Lycium shawii, Ochradenus baccatus, Rhazya stricta, Convolvulus oxyphyllus, Zilla spinosa, Senna italica, Pulicaria undulata, Rhanterium epappsoum, etc. Some of the previous studies categorized the vegetation of An-Nafud desert into four groups. They are annual vegetation cover, Haloxylon persicum-Artemisia monosperma-Stipagrostis drarii community, Calligonum comosum-Artemisia monosperma-Scrophularia hypercifolia community and ecotone communities. The ecotone community is further divided into Hamada-Calligonum-Piturathos triradiatus-Scrophularia community and Ranterium-Calligonum-Pituranthos-Scrophularia community.  These communities have remarkable representation in sand dunes such as lower dune and upper dune or middle dune areas. However, Calligonum-Artemisia-Scrophularia community is the most widely spread plant groups in the entire Nafud area.

 

            Majority of species in the Hail region are annuals. The representation of trees is insignificant, represented by only 1%. Members of Composite dominate the flora (Asteraceae-63 species) followed by Gramineae (Poaceae –33 species), Cruciferae (Brassicaceae – 27 species) and Leguminosae (Fabaceae - 20 species). 24 families are monotypic. The largest genus in the flora is Plantago (Plantaginaceae) with 10 species, followed by Astragalus (Leguminosae) with 9 species.   

Flora of Hail Region

 

ACANTHACEAE
Blepharis ciliaris
(L.) B.L. Burtt.

AIZOACEAE
Aizoon canariense L.  
Mesembryanthemum nodiflorurn
L.
 

AMARANTHACEAE 

Aerva javanica (Burm.f.) Juss. ex Schultes

Agathophora alopecuroides (Del.) Fenzl

Atriplex dimorphostegia Kar. & Kir.

Bassia muricata (L.) Asch.

Chenopodium murale L.

Halocnemum strobilaceum (Pallas) M. Bieb.

Halothamnus iraqensis Botsch.  

Haloxylon persicum Bunge ex Boiss.

Haloxylon salicornicum (Moq.) Bunge 

Noaea mucronata (Forssk.) Asch. & Schweinf.

Salsola cyclophylla Baker

Salsola imbricata Forssk.

Salsola tetrandra Forssk. 

Suaeda aegyptiaca (Hasselq,) Zoh.

Suaeda vermiculata  Forssk.

 

AMARYLLIDACEAE 
Allium atroviolaceum
Boiss.
Allium sinaiticum
Boiss.
Allium sindjarense
Boiss. & Hasskn.

Allium stamineum Boiss.


ANACARDIACEAE 
Rhus tripartita
(Urica) Grande
 

ANNONACEAE

Annona squamosa L.

 

APIACEAE / UMBELLIFERAE

Anisosciadium isosciadium Bornm.

Anisosciadium lanatum Boiss.

Deverra triradiata ssp. triradiata (Hochst.) Aschers
Ferula communis
var. communis L.
Foeniculum vulgare
Mill.
Pimpinella puberula
(DC.) Boiss.

 
APOCYNACEAE

(including subfamily- Asclepiadoideae)

Gomphocarpus sinaicus Boiss.

Pergularia daemia (Forssk.) Chiov.

Pergularia tomentosa L.

Periploca aphylla Decne

Rhazya stricta Decne

 

BORAGINACEAE

Alkanna orientalis (L.) Boiss.

Anchusa milleri Willd.
Arnebia decumbens (Vent.) Coss. & Kral
Arnebia hispidissima
(Lehm.) DC.
Arnebia linearifolia
DC. 
Buglossoides arvensis
(L.) I.M. Johnston
Echium horridum
Batt.
Gastrocotyle hispida
(Forssk.) Bunge
Heliotropium bacciferum
Forssk. .
Heliotropium digynum
(Forssk.) Asch. 
Heliotropium ramosissimum
(Lehm.) DC.
Heterocaryum szovitsianum
(Fisch. & Mey) A. DC.
Lappula spinocarpos
ssp. ceratophora (Popov.) Y.J. Nasir
Moltkiopsis ciliata
(Forssk.) I.M. Johnston

Trichodesma africanum var. africanum (L.) R.Br.
 

BRASSICACEAE /CRUCIFERAE

Alyssum homalocarpum (Fischer & Meyer) Boiss.

Anastatica hierochuntica L.

Arabidopsis erisymoides Hedge & Kit Tan

Brassica tournefortii Guan.

Cakile arabica Velen. & Bornm.

Diplotaxis acris (Forssk.) Boiss.

Diplotaxis erucoides (L.) DC.

Eremobium aegyptiacum ssp. lineare (Del.) Boiss.

Farsetia aegyptia Turra

Farsetia burtoniae Oliver.

Farsetia stylosa R.Br.

Hirschfeldia incana (L.) Lagr.

Horwoodia dicksoniae Turril

Isatis lusitanica L.

Lepidium aucheri Boiss.

Maresia pygmaea (Del.) O. Schulz

Matthiola arabica Boiss.

Matthiola longipetala (Vent.) DC.

Morettia canescens Boiss.

Morettia parviflora Boiss.

Moricandia sinaica (Boiss.) Boiss.

Notoceras bicorne (Aiton f.) Amo

Raphanus sativus L.

Savignya parviflora (Del.) Webb

Schimpera arabica Hochst. & Steudel

Sisymbrium irio L..

Zilla spinosa (L.) Prantl.

 
CAPPARACEAE  
Capparis spinosa
var. mucronifolia  (L.) Boiss.

Cleome amblyocarpa Barr. & Murb.
 

CAPRIFOLIACEAE
Valerianella oxyrhyncha
Fisch. & Mey
 

CARYOPHYLLACEAE
Arenaria foliacea
Trurril 

Dianthus cyri Fisch & C.A. Mey.
Gymnocarpos decander
Forssk.
Gypsophila capillaris
(Forssk.) C. Christ.
Gypsophila viscosa
Murray
Herniaria hemistemon
J. Gay
Herniaria hirsuta
L.
Loeflingia hispanica
L.
Paronychia arabica
(L.) DC.
Paronychia chlorothyrsa
Murb.
Petrorhagia cretica
(L.) P. Ball & Heywood
Polycarpaea repens
(Forssk.) Aschers. & Schweinf.
Polycarpaea robbairea
(Kuntze) Greauter & Burdet
Polycarpon tetraphyllum
(L.) L.
Pteranthus dichotomus
Forssk.
Sclerocephalus arabicus
Boiss.

Silene apetala Willd.
Silene arabica
Boiss.
Silene linearis
Decne.

Silene villosa Forssk. 
Spergula fallax (Lowe) Krause
Spergularia diandra
(Guss.) Heldr. & Sart.
 

CISTACEAE

Helianthemum kahiricum Del.
Helianthemum lippii
(L.) Doum.- Cours.
 

COLCHICACEAE

Colchicum ritchii R.Br.
 

COMPOSITAE /ASTERACEAE

Aaronsohnia factorovskyi Warb. & Eig.

Acantholepis orientalis Less. 
Achillea fragrantissima (Forssk.) Schi.- Bip.. 
Anthemis deserti Boiss.

Anthemus edumea Eig.
Anthemis melampodina Del.
Anthemis pseudocotula Boiss.
Anthemis scrobicularis Yavin 
Anthemis sheilae Ghafoor & Al-Turki
Anvillea garcinii (Burm.f.) DC.
Anvillea radiata Coss. & Durr.
Artemisia judaica L. 
Artemisia monosperma Del.
Artemisia sieberi Besser    
Atractylis cancellata L.
Atractylis carduus (Forssk.) C. Christ.
Atractylis mernephthae Aschi. Schweinf.
Calendula tripterocarpa
Rupr.
Carthamus nitidus
Boiss.
Carthamus oxyacantha
M. Bieb..
Centaurea ammocyanus
Boiss.
Centaurea bruguierana
ssp. berlangerana
Centaurea eryngioides
Lam.
Centaurea mesopotamica
Bornm.
Centaurea pseudosinaica
Czerp.
Centaurea scoparia
Sieb. ex. Spreng.
Centaurea sinaica
DC.
Conyza bonariensis
(L.) Cronq.
Crepis kotschyana
(Boiss.) Boiss.
Echinops glaberrimus
DC.
Echinops hystrichoides
Kit-Tan
Filago desertorum
Pomel
Gymnarrhena micrantha
Desf.
Ifloga spicata
(Forssk.) Sch.- Bip.
Koelpinia linearis
Pallas
Lasiospermum brachyglossum
DC.
Launaea angustifolia
ssp. arabica (Boiss.) H. Lindb.
Launaea capitata
(Spreng.) Dandy
Launaea fragilis
(Asso.) Pau
Launaea mucronata
(Forssk.) Muschl.
Launaea nudicaulis
(L.) Hook.f.
Leontodon laciniatus
(Bertol) Widder
Leysera leyseroides
(Desf.) Maire
Osteospermum vaillantii
(Decne.) Norlindh

Pallaenis heirochuntica (Michon) Greater
Phagnalon schweinfurthii
var. androssovii (B.Fedtch.) Qaiser & Lack.
Picris babylonica
Hand-Mazz.
Picris cyanocarpa
Boiss.
Pulicaria incisa
ssp. incisa (Lam.) DC.
Reichardia tingitana 
(L.) Roth.
Rhanterium epapposum
Oliv.
Scorzonera intricata
Boiss.
Scorzonera papposa
DC.
Scorzonera schweinfurthii
Boiss.

Scorzonera syriaca Boiss. & Bl.
Scorzonera tortuosissima
Boiss.
Senecio flavus
(Decne.) Sch.-Bip. ex A. Rich.
Senecio glaucus
L.
Senecio vulgaris
L.
Sonchus asper
(L.) Hill.
Tripleurospermum auriculatum
(Boiss.) Rech. f.

Zoegea purpurea Fresen.

 

CONVOLVULACEAE

Convolvulus oxyphyllus ssp. oxycladus Rech. f.
Convolvulus pilosellifolius
Desr.
Cuscuta planiflora
Tenore

CRASSULACEAE
Crassula alata (Viv.) Berger

Umbilicus horizontalis (Guss.) DC.

 

CUCURBITACEAE

Citrullus colocynthis (L.) Schrader

 

CYNOMORIACEAE  
Cynomorium coccineum L.

 

CYPERACEAE
Cyperus conglomeratus Rottb. 

Cyperus macrorrhizus Nees

Scirpoides holoschoenus (L.) Sojak

DIPSACACEAE
Scabiosa olivieri Coult.  

EPHEDRACEAE 
Ephedra alata Decne.
Ephedra foliata
Boiss. ex C.A. May

 

EUPHORBIACEAE
Acalypha fruticosa var. fruticosa Forssk.
Andrachne aspera Spreng. 
Euphorbia arabica Hochst. & Wteyd,

Euphorbia granulata var. granulata Forssk.

Euphorbia helioscopia L.
Euphorbia peplus
L.
Euphorbia retusa
Forssk.
Euphorbia schimperiana
Scheele
Euphorbia serpens
Kunth
 

 

 

 

FRANKENIACEAE 

Frankenia revoluta Forssk.
 

GENTIANACEAE 
Centaurium pulchellum (SW.) Druce
 

GERANIACEAF 
Erodium ciconium (L,) L'Her
Erodium glaucophyllum
(L,) L'Her
Erodium laciniatum var. laciniatum
(Cav.) Willd.
Erodium laciniatum
var.. pulverulentum (Cav.) Willd.

Erodium oxyrhynchum var. oxyrhynchum M. Bieb.
Geranium biuncinatum
Kokwaro
Geranium mascatense
Boiss.
Geranium molle
L.
Monsonia nivea
(Decne.) Decne. ex Webb.
 

IRIDACEAE  

Moraea sisyrinchium (L.) Ker Gawl.
 

JUNCACEAE
Juncus bufonius L.

 

 LAMIACEAE  / LABIATAE                 
Ballota undulata
(Sieb. ex Fresen.) Benth.
Lallemantia royleana
(Benth.) Benth.
Lavandula pubescens
Decne.
Micromeria imbricata
(Forssk.) C. Christens.
Salvia deserti
Decne.
Salvia lanigera
Poir.
Salvia spinosa
L.
Teucrium oliverianum
Ging. ex Benth.
Teucrium polium
L.

 

LEGUMINOSAE .
Astragalus atropilosus
(Hochst.) Bunge
Astragalus bombycinus
Boiss.
Astragalus collenettiae
Hedge & Podl..
Astragalus hamosus
L.
Astragalus kahiricus
DC.
Astragalus schimperi
Boiss.
Astragalus sieberi
DC.

Astragalus spinosus (Forssk.) Muschl.
Astragalus tribuloides
Del.
Hippocrepis areolata
Desv.
Hippocrepis unisiliquosa
ssp. bisiliqua (Forssk.) Bornm.
Lotononis platycarpa
(Viv.) Pichi.- Serm. .
Medicago laciniata
var. laciniata (L.) Mill.
Onobrychis ptolemaica
(Del.) DC.
Ononis sicula
Guss..
Prosopis juliflora
(SW.) DC.  
Senna italica Miller.
Trigonella stellata Forssk.
Vicia monantha Retz. 

LILIACEAE

Gagea reticulata (Pall.) J.A. & J. H. Schultes
 

MALPIGHIACEAF  
Caucanthus edulis Forssk.

MALVACEAE
Althaea ludwigii
L.
Hibiscus micranthus
L.
Malva parviflora
L.

 

MORACEAE
Ficus palmata
Forssk.

 

NEURADACEAE  
Neurada procumbens L.

 

NITRARIACEAE
Peganum harmala
L.

 

NYCTAGINACEAE  

Commicarpus arabicus Meikle
 

OROBANCHACEAE

Cistanche phelypaea (L.) Cout.


PAPAVERACEAE
Fumaria parviflora
Lam.
Hypecoum pendulum
L.
Roemeria hybrida
ssp. dodecandra (Forssk.) E. A. Durande & Barratte.
 

PLANTAGINACEAE

Antirrhinum orontium L.

Kickxia acerbiana (Boiss.) Tackh. & Boulos

Kickxia aegyptiaca (L.) Nab.

Linaria haelava (Forssk.) Del.

Plantago afra L.

Plantago amplexicaulis Cav.

Plantago boissieri Hausskn. & Bornm.

Plantago ciliata Desf.

Plantago coronopus L.

Plantago cylindrica Forssk.

Plantago ovata Forssk.

Plantago psammophila Agnew & Chalabi-Ka'bi

Veronica anagallis-aquatica ssp. anagallis-aquatica L.


PLUMBAGINACEAE

Limonium lobatum (L.f.) Chaz.

 

POACEAE /GRAMINEAE
Aegilops kotschyi Boiss.
Aristida adscensionis
L.
Avena fatua
L.

Avena sterilis ssp. sterilis L.
Brachypodium distachyum
(L.) Beauv.

Bromus danthoniae Trin.

Bromus fasciculatus Presl.

Bromus sericeus Drobov.

Cenchrus ciliaris L.

Cenchrus pennisetiformis Hochst. & Stedudel ex Steudel

Centropodia forsskaolii (Vahl) Cope

Centropodia fragilis (Guinet & Sauvage) Cope

Cutandia memphitica (Sprengel) K. Richter

Cynodon dactylon (L.) Pers.

Enneapogon desvauxii P. Beauv.

Enneapogon persicus Boiss.

Eragrostis minor Host

Hyparrhenia hirta (L.) Stapf

Lamarckia aurea Moench

Pennisetum orientale L.C. Rich

Pennisetum setaceum (Forssk.) Chiov.

Polypogon monspeliensis (L.) Desf.

Rostraria cristata (L.) Tzvelev

Rostraria pumila (Desf.) Tzvelev

Schismus barbatus (L.) Thell.

Sorghum halepense (L.) Pers.

Stipa capensis Thunb.

Stipagrostis drarii (Tackh. de Wint.

Stipagrostis hirtigluma (Steudel. ex Trin.) & Rupr.) de Wint.
Themeda triandra
Forssk.
Tragus racemosus
(L.) All.
Tricholaena teneriffae
 (L.f.) Link.
Trisetaria chaudharyana
H. Scholz
 

POLYGALACEAE  
Polygala abyssinica R. Br.
Polygala erioptera
DC. 
Polygala negevensis
Danin
 

POLYGONACEAE  
Calligonum comosum
L'Her.
Rumex pictus
Forssk.
Rumex vesicarius
L.

PORTULACACEAE

Portulaca oleracea L.

 

PRIMULACEAE  
Anagallis arvensis var. arvensis L.

 

PTERIDOPHYTES

  

ACROSTICHACEAE

Acrostichum aureum L.

 

ADIANTACEAE

Cheilanthes coriacea Decne.

Cheilanthes villea (Aiton) Domin
 

RESEDACEAE
Caylusea hexagyna (Forssk.) M. L. Green
Ochradenus arabicus
Chaudhary, Hillocat & A.G. Miller
Ochradenus baccatus
Del.
Reseda arabica
Boiss.

RHAMNACEAE  

Ziziphus spina-Christi var. spina-Christi (L.) Willd. 

RUBIACEAE
Callipeltis cucullaris 
(L.) Stev.
Crucianella membranacea
Boiss.
Galium aparine
L.
Galium setaceum Lam.
Pterogaillonia calycoptera
(Decne.) Lincz.
 

RUTACEAE

Haplophyllum tuberculatum (Forssk.) A. Juss.
 
SOLANACEAE
Datura metel
L.
Hyoscyamus muticus
L.
Hyoscyamus pusillus
L.
Lycium shawii
Roem. & Schult.
Solanum nigrum
L.
 

TAMARICACEAE
Tamarix aphylla
(L.) Karst.


THYMELACEAE
Thymelaea mesopotamica
(C. Jeffrey) B. Peterson

URTICACEAF
Forsskaolea tenacissima
L.
Parietaria alsinifolia
Del.

XANTHORRHOEACEAE
Asphodelus tenuifolius
Cav.

Asphodelus refractus Boiss.

Asphodelus viscidulus Boiss.
 

ZYGOPHYLLACEAE
Fagonia bruguieri
DC.
Fagonia glutinosa
Del.

Fagonia olivieri DC.

Tetraena simplex (L.) Beier & Thulin
Tribulus terrestris
var. terrestris L.

Zygophyllum propinquum ssp. migahidii (Hadidi) J. Thomas & Chaudh.

 

Written, designed and maintained by Dr. Jacob Thomas Pandalayil, Dept. of Botany & Microbiology, King Saud University, Riyadh, Saudi Arabia