Nafud Al-Urayq protected area

Nafud Al-Urayq protected area – flora and vegetation

Topography

Nafud Al-Urayq is a narrow protected area, situated in the central part of Saudi Arabia. It is located between 24.750174-25.552082 N and 42.437837-42.580600 E with an area of 1641 km² and a perimeter of approximately 397 km. The area is composed of Quaternary aeolian sand overlying the crystalline rocks. The entire area, away from the dune part is well connected with road network of both asphalt and vehicular tracks, enabling the villagers to access the protected area from all sides, making it one of the difficult areas for monitoring. Two major wadis and their tributaries join at the northern edge of the area. During rainy season the water flows from west to east providing moisture and disseminules to the protected area, depressions remain filled with water for several weeks making the habitat covered with silt conducive for the growth of annuals. Although the entire area is covered by sands, small rock formations, hills or hillocks can be found on the entire eastern side just outside the main sand body. North eastern sides of the protected areas are also bordered by isolated rocky hillocks and inselbergs, mostly devoid of any vegetation.

Floristic Analysis

135 species belonging to 108 genera in 37 families have been recorded from the area. Among these, Poaceae (19 spp.) is the largest family followed by Asteraceae and Leguminosae with 19 and 11 species respectively. 16 families are represented by only one species each. Tree species are few in the surveyed area, represented by only 2 (1.5%) species, namely, Acacia raddiana and Tamarix aphylla. Herbs and subshrubs (perennial herbs) are the major categories with 63 (47.7%) and 38 (28.1%) species respectively, followed by perennial grasses and shrubs with 16 (11.9%) and 11(8.1%) species respectively. The share of annual grasses in the study area is insignificant, represented by only 5 (3.7%) species, such as Aristida adscensionis, Phalaris minor and Schismus barbatus. Since the protected area is located within the Saharo-Arabian phytogeographical zone, highest number of species comes from this zone. An approximate 43% (58 spp.) belong to this category, followed by 14 % (19 spp.) from Saharo-Arabian- Irano Turanian category. However, there are incursions of species from other phytogeographical zones such as, Mediterranean, Somalia Masai or Tropical regions.

Location of Nafud Al-Urayq An outline of the flora of Nafud Al-Urayq.

Life-form spectrum of Nafud Al-Urayq.

Vegetation map of Nafud Al-Urayq H. salicornicum community

Vegetation of Nafud Al-Urayq

The terrain of Nafud Al-Urayq is located in an extra arid zone and composed mainly of xeromorphic shrubs and herbs. Although the terrain falls within a arid phytogeographical zone, there are intrusions of species from other phytogeographical zones such as Acacias and Astragalus of Somalia Masai and Irano-Turanian zones respectively. Majority of species belonging to the Saharo-Arabian zone are annuals with either xeromorphic adaptations or live only for a short period. The duration of life of annuals in this area varies from year to year, depending upon the favourable conditions. If the area receives sufficient quantity of rain in a season, density and abundance of herbaceous flora are significantly high while in years of drought, only a few disseminules of the herbs could germinate and produce few flowers and seeds. Depending on the amount precipitation, the overall stature of these plants also varies from a retarded height to normal heights. Haloxylon persicum is the major component of Nafud Al-Urayq, dominating the northern half of the surveyed area, while Acacias (A. ehrenbergiana, A. raddiana and A. tortilis) and xeromorphic dwarf shrublets (Anvillea garcinii, Blepharis ciliaris, Gymnocarpos decander, Sclerocephalus arabicus, etc. dominate the hillocks and shallow depressions of the southern part. H. persicum is characteristic of the mobile dune area which is also home to a number of shrubs, subshrubs and herbs such as H. salicornicum, Moltkiopsis ciliata, Schismus barbatus, Plantago boissieri, etc. Calligonum comosum, a previously dominant population sharing with H. persicum in the northern and central part is now in a highly degraded state, majority of which are either dead or with a few live branches. Herbaceous flora and other grasses are usually found in depressions where silt and soil accumulates. Subshrubs and shrubs dominate the southern edge of the protected area, mostly found at foot hills or in crevices among hillocks. Haloxylon salicornicum community is mainly dominating in the southern parts and along the periphery of the northern half where the sand is less mobile. Non palatable tropical element, Calotropis procera and the common desert component Rhazya stricta are not prominent in the surveyed area, primarily due to the restrictions to the domesticated herbs. The palatable grass, Panicum turgidum dominates along the southern side, where it shares the habitat of A. ehrenbergiana, and A. tortilis and a number of annuals, such as Plantago spp., Brassica tourneforte, Centaurea pseudosinaica, Ifloga spicata, Anisosciadium lanatum, etc. 23 locations were selected as sample spots for recording the cover value of populations. An analysis of these values has shown that, the entire vegetation can be divided into 5 communities or vegetation groups, each located in specific habitat. Some species are widely distributed with appreciable abundance while others are with restricted distribution range. The characteristic communities are as follows:

Haloxylon salicornicum community: This community is highly scattered in the northern and southern part of Nafud Al-Urayq. It also dominates in the depressions and semi sabkha areas where rain water accumulates during rainy days. Other species equally dominant in this community are Pulicaria undulata and the non-palatable species Euphorbia retusa (Fig. 6) and E. dracunculoides. Major components of this community are: Ajuga arabica, Andrachne telephoides, Capparis spinosa, Citrullus colocynthis, Euphorbia retusa, E. dracunculoides, Haloxylon salicornicum, Pulicaria undulata

Haloxylon salicornicum-Pulicaria undulata community: dominates in the southern and northern edge of Nafud Al-Urayq, mostly composed of herbaceous flora along the periphery and edges of sand dunes. This community is usually found on low altitude sand dunes of southern sides and on sand sheets of the northern side with less mobile sand. It contains the highest diversity both in terms of abundance and density. Presence of Capparis spinosa along with Pulicaria undulata as a co-dominant species indicates the area as a shallow depression receiving excess quantity of silt and sand. Majority of species in this community other than the dominant ones are herbs except for a species such as Kohautia caespitose, Senna italica, etc. Low lying areas between dunes support a small population of A. ehrenbergiana. Major components of this community are: Acacia ehrenbergiana, Anisosciadium lanatum, Anthemis deserti, Arnebia hispidissima, Asphodelus tenuifolius, Atractylis carduus, Bassia muricata, Capparis spinosa, Cleome amblyocarpa, Eremobium lineare, Erodium laciniatum, Fagonia glutinosa, Farsetia stylosa, Horwoodia dicksoniae, Koelpinia linearis, Kohautia caespitosa, Launaea capitata, L. mucronata, Lotononis platycarpa, Malva parviflora, Neurada procumbens, Pergularia tomentosa, Plantago amplexicaulis, P. boissieri, P. ciliata, Pulicaria undulata, Reseda arabica, Savignya parviflora, Senna italica

Sabkha sub-community: This community is the smallest among all other prominent ones and therefore not significant in the study area. Distribution of this community is highly restricted, found only along the edges of water logged area. It is dominated by Tetraena propinqua associated with Haloxylon salicornicum. Other associated species in the community are: Cistanche phylepaea, Haloxylon salicornicum, Tamarix nilotica, Tetraena propinqua (=Zygophyllum migahidii)

Haloxylon salicornicum-Pulicaria undulata community. Sabkha sub community (Tetraena propinqua community)

Haloxylon persicum community: It is the largest community in Nafud Al-Urayq, covering majority of sandy areas. H. persicum, the keystone species of the area, is a large shrub, reaching a height of about 3 meters. This Irano Turanian species is an important component of the sand seas and its population often forms into an isolated ‘island’. Earlier villagers used to gather its branches to use as firewood. Other major species sharing this habitat are: Caltotropis procera, Centropodia forsskalei, Citanche phylepaea, Cyperus conglomeratus, Eremobium lineare, Haloxylon salicornicum, Moltkiopsis ciliata, Monsonia nivea, Polycarpaea repens, Polygala erioptera, Stipagrostis drarii.

Acacia raddiana-Panicum turgidum community: Sand dunes are absent in the southern part of the surveyed area. The terrain is rocky overlaid by a sheet of less mobile sand. Slopes of small hillocks are somewhat vegetated with subshrubs and shrubs such as Ephedra foliata, Lycium shawii, Hibiscus micranthus, Gymnocarpos decander while the flat wadi bed with a mixture of sand and silt support the growth annuals such as Launaea capitata, Savignya parviflora, Horwoodia dicksoniae citrullus colocynthis, Senecio flavus, Launaea spp. , etc. The population of Acacia raddiana is somewhat healthy, some reaching a height of about 6 meters and above, indicating less grazing. Major components of this community are : Acacia raddiana, Acacia tortilis, Aerva javanica, Aristida adscensionis, Asphodelus tenuifolius, Asteriscus heirochunticus, Blepharis ciliaris, Centarurea pseudosinaica, Centaurea bruguieri, Chrysopogon plumulosus, Citrullus colocynthis, Convolvulus oxyphyllus, Diplotaxis acris, Emex spinosa, Ephedra foliata, Eragrostis barrelieri, Haplophyllum, tuberculatum, Hibiscus micranthus, Hyparrhenia hirta, Launaea capitata, Launaea nudicaulis, Lycium shawii, Morettia parviflora, Panicum turgidum, Paronychia arabica, Pergularia tomentosa, Plantago ovata, Pulicaria incisa, Pulicaria undulata, Senecio flavus, Teucrium polium, .Zilla spinosa

Calligonum comosum-Haloxylon salicornicum community Haloxylon persicum community

Calligonum comosum-Haloxylon salicornicum community: The population of Caliigonum comosum is in a highly depauperate stage, majority of them are in a dying stage, primarily due to intensive wood cutting by nearby villagers prior to the declaration of the area as a protected one. Two types of flowers are seen in this population. However, individual plant maintains the colour of the fruits, either as red or yellow. This shrub is very popular throughout Arabian Peninsula for its excellent firewood which can be used as long and clear burning firewood with less smoke. Major part of this habitat contains mobile sand dunes and therefore contains fewer numbers of species. All species recorded under this community are purely psammophytes having adapted xeromorphic features. Dominant and associated species of this community are as follows: Calligonum comosum, Cistanche phylepaea, Cyperus conglomeratus, Eremobium lineare, Gisekia pharnaceoides, Haloxylon salicornicum, Moltkiopsis ciliata, Monsonia nivea, Morettia parviflora, Stipagrostis drarii

Species found in Nafud Al-Urayq

Population Cover: A=Abundant; L=Locally Abundant; R=Rare

Chorotype: SA= Saharo Arabian; SM= Somalia Masai; TR=Tropical; Med-SA= Mediterranean –Saharo Arabian; Paleotropic; SA-IT= Saharo Arabia-Irano Turanian; SA-SH= Saharo Arabia-Sahel; SA-SM= Saharo Arabian – Somalia Masai; SM-SH=Somalia Masai-Sahel

Distribution: Najd= Central Region; E= Eastern Province; N=Northern Region; SW=Southwestern Region; NW=Northwestern Region; S=Southern Region.

Family	*Species*	Lifeform	Population Cover	Habitat	Chorotype	Distribution in Saudi Arabia
Acanthaceae	Blepharis ciliaris	Herb	L	Foothills and Slopes	SA-SH	Najd, E, N, SW, S
Amaranthaceae	Aerva javanica	Subshrub/	L	Slopes of Hillocks	Paleotropic	Najd, E, N, SW, NW, S
	Bassia muricata	Herb	L	Foothills	SA-IT	Najd, E, N,
	Halothamnus iraqensis	Subshrub	R	Slopes of hills	SA	Najd, E, N
	Haloxylon persicum	Shrub	A	Sand dunes	IT	Najd, E, N
	Haloxylon salicornicum	Subshrub	A	Sand sheets	SA	Najd, N, E, SW, NW
Apiaceae	Anisosciadium lanatum	Herb	L	Foothills and Slopes	SA	Najd, N, E, NW
Apocynaceae	Calotropis procera	Shrub	L	Depressions, open plains	SM-SH	Najd, E, N, SW, NW, S
	Glossonema boveanum ssp. boveanum	Subshrub	R	Foothills and Slopes	SM-SH	Najd, N, NW
	Glossonema variens	Subshrub	R	Foothills and Slopes	SM-SH	Najd, E, N, NW
	Pergularia tomentosa	Subshrub	R	Foothills and Slopes	SM-SH	Najd, E, N, S
Asphodelaceae	Asphodelus refractus	Herb	R	Depressions	SA	Najd, E, N, SW, NW, S
	Asphodelus tenuifolius	Herb	A	Depressions	SA-SH	Najd, E, N, SW, NW, S
Asteraceae	Anthemis deserti	Herb	L	Depressions	SA	Najd, E, N, NW
	Anvillea garcinii	Subshrub	L	Foothills and Slopes	SA	Najd, E, N, NW
	Asteriscus heirochunticus	Herb	L	Foothills and Slopes	SA	Najd, E, N, S
	Atractylis carduus	Herb	L	Foothills and Slopes	SA	Najd, E, N
	Centaurea bruguieriana	Herb	L	Foothills and Slopes	SA	Najd, E, N
	Centaurea pseudosinaica	Herb	L	Foothills and Slopes	SA	Najd, E, N, SW, NW, S
	Centaurea sp.	Herb		Foothills and Slopes	SA	Najd, E, S
	Echinops polyceras	Subshrub	R	Foothills and Slopes	IT	Najd, N
	Filago desertorum	Herb	A	Depressions	SA-IT	Najd, E, N
	Ifloga spicata	Herb	A	Foot hills, hill slopes, Depressions	SA	Najd, E, N
	Koelpinia linearis	Herb	L	Foothills and Slopes	SA-IT	Najd, E, N
	Launaea capitata	Herb	A	Open plains, depressions	SA	Najd, E, N, SW, NW, S
	Launaea mucronata	Herb	L	Foothills and Slopes	SA	Najd, E, N, SW, NW, S
	Launaea nudicaulis	Herb	L	Foothills and Slopes	SA	Najd, E, N, SW, NW, S
	Picris babylonica	Herb	A	Foothills and Slopes	SA-IT	Najd, E, N
	Pulicaria incisa	Subshrub	R	Foothills and Slopes	SA	Najd, E, N, NW
	Pulicaria undulata	Subshrub	A	Open plains	SA-SM	Najd, E, N, SW, NW, S
	Rhanterium epapposum	Subshrub	L	Open plains	SA	Najd, E, N, NW
	Senecio flavus	Herb	L	Slopes of Hillocks	SA	Najd, E, N, NW
Boraginaceae	Anchusa sp.	Herb	R	Slopes of Hillocks	SA	Najd, E, N, SW, NW
	Arnebia hispidissima	Herb	A	Open plains	SA	Najd, E, N, SW, NW, S
	Heliotropium bacciferum	Subshrub	L	Open plains	SA-SH	Najd, E, N, SW, NW, S
	Heliotropium digynum	Subshrub	A	Sand dunes	SA	Najd, E, N, NW
	Moltkiopsis ciliata	Subshrub	A	Sand dunes	SA	Najd, E, N, NW, S
	Trichodesma africanum	Subshrub	L	Slopes of Hillocks	SA-SH	Najd, E, N, SW, NW, S
Brassicaceae	Brassica tourneforte	Herb	R	Slopes of Hillocks	Med-SA	Najd, E, N
	Diplotaxis acris	Herb	R	Slopes of Hillocks	SA	Najd, E
	Diplotaxis harra	Herb	R	Slopes of Hillocks	SA	Najd, E
	Eremobium lineare	Herb	A	Sand dunes	SA	Najd, E, N, NW
	Farsetia aegyptiaca	Subshrub	L	Slopes of Hillocks	SA-SH	Najd, E, N, SW, NW, S
	Farsetia stylosa	Subshrub	L	Slopes of Hillocks	SA-SH	Najd, E, N, SW, NW, S
	Horwoodia dcksoniae	Herb	L	Foot hills	SA	Najd, E, N
	Morettia parviflora	Subshrub	L	Slopes of Hillocks	SM	Najd, E, N
	Savignya parviflora	Herb	L	Foot hills and depressions	SA	Najd, E, N
	Schimpera arabica	Herb	L	Slopes of Hillocks	SA	Najd, E, N, SW, NW, S
	Zilla spinosa	Herb	L	Foot hills	SA	Najd, E, N, SW, NW
Capparaceae	Capparis spinosa	Shrub	A	Depressions	Med-SA	Najd, E, N
	Cleome amblyocarpa	Herb	L	Depressions	SA-SM	Najd, E, N, SW, NW, S
Caryophyllaceae	Gymnocarpos decander	Subshrub	L	Slopes of Hillocks	SA	Najd, E, N, NW
	Paronychia arabica	Herb	L	Depressions	SA	Najd, E, N
	Polycarpaea repens	Subshrub	A	Sand dunes	SA-SM	Najd, E, N, NW
	Sclerocephalus arabicus	Subshrub	L	Slopes of Hillocks	SA	Najd, E, N, NW, S
	Silene villosa	Herb	A	Sand dunes	SA	Najd, E, N, NW
	Spergula fallax	Herb	L	Depressions	SA	Najd, E, N, NW, S
Cistaceae	Helianthemum lippii	Subshrub	R	Slopes of Hillocks	SA-SM	Najd, E, N, NW
Convolvulaceae	Convolvulus buschiricus	Subshrub	R	Slopes of Hillocks	SA	Najd, E, N, NW, S
	Convolvulus oxyphyllus ssp. oxycladus	Subshrub	R	Open plains	SA	Najd, E, N, NW, S
	Convolvulus pilosellifolius	Subshrub	L	Depressions	IT	Najd, E, N, NW, S
Cucurbitaceae	Citrullus colocynthis	Subshrub	A	Depressions	SA	Najd, E, N, SW, NW, S
Cynomoriaceae	Cynomorium coccineum	Subshrub	R	Sand dunes	Med-IT-SA	Najd, E, N
Cyperaceae	Cyperus conglomeratus	Subshrub	A	Sand dunes	SA	Najd, E, N, NW
Ephedraceae	Ephedra foliata	Shrub	R	Slopes of Hillocks	SA-IT	Najd, E, N, SW, NW, S
Euphorbiaceae	Andrachne telephioides	Subshrub	L	Depressions	Med-IT	Najd, E, N
	Euphorbia dracunculoides	Subshrub	A	Depressions	SA	Najd, E
	Euphorbia granulata	Subshrub	A	Open plains, depressions	SA-SM	Najd, E, N, SW, NW, S
	Euphorbia retusa	Subshrub	A	Depressions	SA	Najd, E, N, NW
Fabaceae	Acacia raddiana	Tree	A	Open plains, wadi channels	SM	Najd, E, N
	Acacia ehrenbergiana	Shrub	L	Open plains, wadi channels	SM	Najd, E, N, NW
	Acacia tortilis	Shrub	L	Open plains, wadi channels	SM	Najd, E, N, SW, NW, S
	Astragalus caprinus	Herb	R	Depressions	SA-IT	Najd, E, N
	Astragalus schimperi	Herb	L	Depressions	SA-IT	Najd, E, N
	Astragalus tribuloides	Herb	L	Depressions	SA-IT	Najd, E, N, NW
	Astragalus spinosus	Subshrub	L	Depressions	SA-IT	Najd, E, N
	Lotononis platycarpos	Herb	A	Open plains, Sand sheets	SA-SM	Najd, E, N, NW
	Medicago laciniata	Herb	L	Depressions, slopes of hillocks	SA	Najd, E, N, NW, S
	Senna italica	Subshrub	L	Open plains	SM	Najd, E, N, SW, NW, S
	Tephrosia purpurea	Subshrub	R	Open plains Slopes of hills	SM	Najd, E, N, SW, NW, S
Geraniaceae	Erodium laciniatum	Herb	L	Open plains	Med	Najd, E, N, SW, NW, S
	Monsonia heliotropoides	Herb	R	Open plains	SM	Najd, E, NW
	Monsonia nivea	Herb	A	Sand dunes	SA-SM	Najd, E, N
Lamiaceae	Ajuga arabica	Subshrub	L	Depressions	IT	Najd, N
	Salvia deserti	Subshrub	R	Slopes of hills	SA	Najd, E, N, NW, S
	Teucrium polium	Subshrub	R	Slopes of hills	Med-IT	Najd, E, N, NW
Liliaceae	Gagea sp.	Herb	R	Open plains	Med-SA	Najd, E, N
Malvaceae	Althaea ludwigii	Herb	L	Depressions	SA	Najd, E, N, SW, NW, S
	Hibiscus micranthus	Shrub	L	Slopes of hills	Paleotropic	Najd, E, N, SW, NW, S
	Malva parviflora	Herb	L	Depressions	Med-IT	Najd, E, N, SW, NW, S
Molluginaceae	Gisekia pharnaceoides	Herb	A	Open plains, sand sheets	TR	Najd, E, NW, S
Neuradaceae	Neurada procumbens	Herb	A	Sand sheets	SA	Najd, E, N, NW
Orobanchaceae	Cistanche phelypaea	Subshrub	L	Sand dunes	SA-IT	Najd, E, N
Plantaginaceae	Plantago amplexicaulis	Herb	L	Slopes of hills	SA	Najd, E, N, SW, NW, S
	Plantago boissieri	Herb	A	Sand dunes, sand sheets	SA	Najd, E, N, NW
	Plantago cilata	Herb	A	Depressions and sand sheets	SA	Najd, E, N
	Plantago ovata	Herb	A	Depressions and sand sheets	SA-IT	Najd, E, N
Poaceae	Aristida adscensionis	Annual	A	Sand dunes	SA	Najd, E, N, NW
	Aristida funiculata	Perennial	L	Sand dunes	SA	Najd, E, N
	Brachypodium distachyon	Annual grass	L	Slopes of hills	Med-IT-SA	Najd, E, N, NW, S
	Cenchrus ciliaris	Perennial grass	L	Slopes of hills	TR	Najd, E, N, SW, NW, S
	Centropodia forsskalii	Perennial	A	Sand dunes	SA-IT	Najd, E, N
	Chrysopogon plumulosus	Perennial	R	Slopes of hills	SA-SM	Najd, E, N, NW, S
	Cynodon dactylon	Perennial	A	Slopes of hills, depressions	TR	Najd, E, N, SW, NW, S
	Enneapogon desvauxii	Perennial	L	Slopes of hills	SA-IT	Najd, E, N
	Eragrostis barrelieri	Perennial	L	Slopes of hills	Med-SA	Najd, E, N, SW, NW, S
	Hyparrhenia hirta	Annual	L	Slopes of hills	Med-IT-SA	Najd, E, N
	Lolium persicum	Annual	R	Slopes of hills, depressions	IT	Najd, E, N, SW, NW, S
	Ochthochloa compressa	Perennial	L	Slopes of hills	SA-IT	Najd, E
	Panicum turgidum	Perennial	A	Open plains, foot hills	SA-SM	Najd, E, N, SW, NW, S
	Phalaris minor	Annual	L	Depressions	Med-IT	Najd, E, N, NW
	Schismus barbatus	Annual	L	Depressions	SA-IT	Najd, E, N
	Stipagrostis ciliata	Perennial	R	Sand dunes	SA	Najd, E, N, NW
	Stipagrostis drarii	Perennial	A	Sand dunes	SA	Najd, E, N, NW, S
	Stipagrostis hirtigluma	Perennial	R	Sand dunes	SA
	Stipagrostis obtusa	Perennial	L	Sand dunes	SA-IT	Najd, E, N
	Stipagrostis plumosa	Perennial	A	Sand dunes	SA-IT	Najd, E, N
	Tetrapogon villosus	Perennial	L	Slopes of hills	SA-SM	Najd, E
Polygalaceae	Polygala erioptera.	Subshrub	R	Slopes of hills	SA-SM	Najd, E, N, SW, NW
Polygonaceae	Calligonum comosum	Shrub	L	Sand dunes	SA-IT	Najd, E, N
	Emex spinosa	Herb	L	Depressions	Med-SA	Najd, E, N, SW, NW, S
	Rumex vesicarius	Herb	L	Slopes of hills, Depressions	SA	Najd, E, N, SW, NW, S
Polypodiaceae	Cheilanthus sp.	Subshrub	R	Moist hill slopes	SA-IT	Najd, E, N, SW, NW
Resedaceae	Ochradenus baccatus	Shrub	L	Slopes of hills	SA-SM	Najd, E, N, SW, NW, S
	Reseda arabica	Herb	R	Depressions	SA	Najd, E
Rubiaceae	Kohautia caespitosa	Subshrub	R	Slopes of hills	SA-SM	Najd, E, N, SW, NW, S
Rutaceae	Haplophyllum tuberculatum	Subshrub	L	Open plains	SA	Najd, E
Solanaceae	Lycum shawii	Shrub	L	Foot hills	SA-SH	Najd, E, N, SW, NW, S
Tamaricaceae	Tamarix aphylla	Tree	R	Abandoned farms	SM	Najd, E, N, SW, NW, S
	Tamarix nilotica	Shrub	L	Saline area/sabkha	SA	Najd, E, N, SW, NW, S
Urticaceae	Forsskaolea tenacissima	Subshrub	L	Slopes of hills	SA-SM	Najd, E, N, SW, NW, S
Zygophyllaceae	Fagonia bruguieri	Subshrub	A	Slopes of hills	SA	Najd, E, N, SW, NW, S
	Fagonia glutinosa	Subshrub	A	Sand sheets	SA	Najd, E, N, NW, S
	Seetzenia lanata	Herb	L	Sand sheets	SM	Najd, E
	Tetraena propinqua	Subshrub	A	Saline area/sabkha	SA	Najd, E, N, NW
	Tribulus terrestris var. terrestris	Herb	L	Depressions, hill slopes	Paleotropic	Najd, E, N, SW, NW, S

Site conceived and maintained by Dr. Jacob Thomas, Dept. of Botany & Microbiology, King Saud University, Riyadh,

Saudi Arabia.