THE VASCULAR PLANTS OF ABU DHABI EMIRATE

Transcription

1 THE VASCULAR PLANTS OF ABU DHABI EMIRATE Gary Brown & Sabitha Sakkir Terrestrial Environment Research Centre Environmental Research & Wildlife Development Agency August 2004

2 THE VASCULAR PLANTS OF ABU DHABI EMIRATE Gary Brown & Sabitha Sakkir ISSUE SHEET Prepared and Dr Gary Brown submitted by: Sabitha Sakkir Checked and approved by: Issue Status: Purpose of Issue: Team Members: Authorised by: Ref.: John Newby Final Internal report, may be distributed externally Brown, Gary // Sakkir, Sabitha Assistant Secretary General for Science and Research (Habitat Restoration Project) REVISION SHEET Revision no. Date Affected Date Change By Pages Made version , 5, 6, G.Brown Authors addresses: Dr Gary Brown & Sabitha Sakkir, ERWDA, TERC, PO Box 45553, Abu Dhabi, UAE

3 THE VASCULAR PLANTS OF ABU DHABI EMIRATE Contents 1. Introduction Environmental Setting Climate Soils Landforms and major habitat types Vegetation and flora Vegetation Flora Biogeography Threats to the vegetation and flora Acknowledgements References Appendix 1: Checklist of the vascular flora of Abu Dhabi Emirate

4 The Vascular Plants of Abu Dhabi Emirate 1. Introduction Covering an area of ca km 2, Abu Dhabi is the largest of the seven Emirates that make up the United Arab Emirates (Figure 1). Scientific work on the flora of the region commenced only fairly recently, with one of the first comprehensive publications dealing with the vascular plants of the country being produced by Western (1989). The main objective of this report is to provide a provisional checklist of the vascular plant species for Abu Dhabi Emirate. This checklist will serve as a basis for further studies and activities, including ultimately the drawing up of a Red Data List, i.e. a list of species that are either threatened or potentially threatened. At present, there is sparse information on the threat status of plants in the Emirate, and in the country as a whole. In addition to providing a checklist of species, an attempt has been made to associate plant species with major habitat types. Although not complete, this information will serve several purposes, including to indicate the ecological requirements of plants, contribute to the development of Figure 1. Map of Abu Dhabi Emirate showing important towns and locations. AA = Al Ain, AD = Abu Dhabi island, AH= Al Hayer, JD = Jebel Dhanna, JH = Jebel Hafit, Mi = Mirfa, Mz =Medinat Zayed, RG = Ra s Ghanadha, Ru = Ruwais, Si = Sila a, Sw = Sweihan, Zi = Zirku

5 species management and recovery plans, provide direction to habitat restoration efforts and to generally enhance sciencebased conservation research. In short, this will place the Emirate in a better position to meets its commitments in respect of the Convention on Biological Diversity, specifically the Global Strategy for Plant Conservation. Apart from our own field studies, this checklist of species is based on work carried out by Western (1989), Jongbloed et al. (2000) and Jongbloed et al. (2003). Specimens of many species are stored in the ERWDA Herbarium. Due to the general paucity of available data, it is clear that information will need to be updated on a regular basis. We therefore welcome any information and constructive comments that can contribute to this process. 2. Environmental setting 2.1. Climate The climate of most of the region is hot and dry throughout most of the year, and according to the UNEP classification of drylands, can be regarded as hyperarid (Middleton & Thomas, 1997). Along a narrow coastal strip, climatic conditions are slightly less extreme, especially towards the north-east. Arid to semi-arid conditions occur in the Hajar Mountains in the far east of the country, but outside of Abu Dhabi Emirate. Temperatures are generally very high during the summer (May to October), with daytime values regularly exceeding 45 C. At night they rarely drop below 30 C. Winters are cooler, but even at night, temperatures below 5 C are uncommon. Mean annual temperatures are in the region of 27 C (Böer, 1997). Rainfall varies considerably throughout the Emirate, but the long-term annual mean is about 90 mm for most of the area, including Abu Dhabi island (see Böer, 1999). Slightly higher precipitation amounts are received towards the mountains in the east, with a mean of about 100 mm in Al Ain. The lowest rainfall (mean 46 mm) occurs in the west of the Emirate. In Bu Hasa (SW of Medinat Zayed), it was so low that it was not even properly recordable over a 12 year period. Even on the coast, mean precipitation for Jebel Dhanna was merely 46 mm over a 16-year period. Furthermore, seasonal variation in rainfall amounts is a pronounced feature. For instance, over a 23-year observation period ( ) in Al Ain, total annual rainfall ranged from 1 to 303 mm, (Böer, 1997)

6 Rainfall occurs mainly in the winter months, but is possible at any time of the year Soils Due to the harsh climatic conditions, natural soils consist mostly of the little-altered parent material. Sand sheets and sand dunes cover large expanses of the Emirate. Coastal sands are rich in calcium carbonate, as they are derived from marine organisms. Calcium-poor red sands on the other hand predominate in the interior. Towards the mountains, gravels and more rocky substrate become more apparent. Gravelly substrate also occurs in many north-western regions. Aeolionite exposures are scattered throughout the Emirate, especially in coastal areas. Sabkha is a characteristic feature of many coastal areas, often covering large areas. Inland sabkha is also found on many interdunal plains, especially in the Al Khatam and Liwa areas (Brown, 2004). Biological activity in the soils is very low, as they contain virtually no organic material. As a consequence, they are highly deficient in nitrogen, and are generally regarded as poor in terms of nutrient status. Natural soil salinity away from the coast is largely dependent on the proximity of the water table to the surface, and the extent to which flooding takes place after heavy rainfall. In some areas, soil salinity has increased in recent years due to unsuitable irrigation practices, ultimately leading to the abandonment of agriculture Landforms and major habitat types A large proportion of Abu Dhabi Emirate is covered by sand sheets and sand dunes, with extensive gravelly plains found in the north-west and north-east. Jebel Hafit, located to the south of Al Ain, is the only mountain to occur in the Emirate. Using satellite imagery to analyse the broad geomorphology of the Emirate, Böer & Gliddon (1997) distinguished six major geomorphological regions (Figure 2). These are: I. Al Khatam area II. Umm Al Zamul-Sweihan area III. Liwa IV. Western & Central Desert V. Al Ain region VI. The Gulf (coastal) region In general, these units are potentially of great practical use for identifying and interpreting the distribution patterns of plant - 6 -

7 Figure 2. The six major geomorphological regions of Abu Dhabi Emirate recognised by Böer & Gliddon (1997). species in the Emirate. For this reason, they are retained, and should any refinement be necessary, this can be carried out when sufficient data have been collected. Four major landform classes (sand sheets, gravel plains, saline flats and mountains) were used to develop a simplified landform classification system for Abu Dhabi Emirate and adjacent areas (Böer & Gliddon, 1997). These major classes were further divided into a number of subclasses. However, this categorisation has proved unsatisfactory for a number of reasons, not least because certain landform types are missing, and also because of the terminology, which is not always consistent with standard usage. More appropriate to the needs of conservation work is a list of major habitat types, which combine landform, broad vegetation types and dominant soil characteristics. We are presently compiling such a list for the Emirate. Due to the current lack of data of sufficient quality to assign many plant species to the detailed categories used in the list of major habitat types, a modified, more general version has been adopted for this report (see Appendix 1), differentiating eight main categories, as well as a ninth to provide information on the distribution status of - 7 -

8 plants on offshore islands, where data are particularly scanty (see Appendix 1). The nine categories are: 1. Coastal habitats 2. Sabkha 3. Sand sheets, dunes and mega dunes 4. Alluvial and interdunal plains 5. Mountains, rocky terrain and wadis 6. Inland water habitats 7. Oases, farmland, plantations 8. Urban habitats 9. Offshore islands Coastal habitat types encompass a wide variety of different habitats, including mudflats, lagoons, sandy and rocky beaches, coastal cliffs, coastal plains, sand sheets and low dunes. All are influenced to a certain degree by elevated salinity levels in the substrate, with the exception of coastal sand sheets and low dunes, where salinity is not always a determining environmental factor. Coastal white sands, a highly distinct habitat type (Figure 3), are also included here. Sabkha is developed in both coastal areas and inland on interdunal plains. In this highly saline environment, plant species, almost invariably halophytes, tend to be limited to the margins of it, or on thin layers of sand that accumulate locally on the surface (Figure 4, see also Brown, 2004). Figure 3. Coastal white sands are species-rich habitats of outstanding conservation value. The tall grass in the foreground is Halopyrum mucronatum (see also Figure 10), known only from several locations in Abu Dhabi Emirate, here near Ra s Ghanadha

9 Figure 4. Coastal sabkha is often devoid of vegetation (background), but where there is a thin veneer of sand on the surface, halophytes, in this case Halopeplis perfoliata (Chenopodiaceae), can form extensive stands. Figure 5. Dunes cover a substantial percentage of Abu Dhabi Emirate. One of the most common species found in such habitats is the sedge Cyperus conglomeratus

10 15), the latter particularly in some eastern regions. Figure 6. Dipterygium glaucum (Capparaceae) is a widespread dwarf shrub found on sand sheets and dunes. Sand sheets, dunes (Figure 5) and megadunes occupy by far the largest land area of the Emirate, and are usually colonised by dwarf shrubs (Figure 6, see also Figure 16), graminoids, or even trees (see Figure As a broad and convenient generalisation, it is possible to differentiate between alluvial and interdunal plains. Alluvial plains are developed over large expanses in the east of the Emirate towards the Hajar Mountains, and have a coarse gravelly to rocky substrate. They are also found in some western parts, especially towards the coast, where the substrate tends to be somewhat finer. Interdunal plains are developed between the numerous dune fields in many parts of the Emirate. In the context of this report, this category refers to non-saline (at best slightly saline) plains, Figure 7. Haloxylon salicornicum (Chenopodiaceae) is a characteristic dwarf shrub of interdunal plains and low sand dunes, especially in the northern half of the Emirate

11 as sabkha, which is also developed on some interdunal plains (especially in the Liwa, Al Khatam areas), is treated separately under Sabkha. The category Mountains, rocky terrain and wadis covers the rocky mountain slopes of Jebel Hafit, but also Tertiary jebels (rocky exposures characteristic of some coastal and inland areas), escarpments, large areas of aeolionite, etc. Wadis are generally associated with Jebel Hafit (Figure 8), although some large wadi beds extend into the plains, especially in the vicinity of Al Ain. Some oases are natural landscape features, others are distinctly anthropogenic, but due to their floristic similarities, they are treated as one category together with plantations and agricultural land. Urban habitats refers specifically to anthropogenic types commonly associated with larger towns and cities, such as parks, roadside verges, etc. As already mentioned, offshore islands, which encompass most of the habitat types listed above, are treated in a separate category. Figure 8. Acacia tortilis (Mimosaceae) is the physiognomically dominant species of alluvial plains and rocky slopes in the eastern part of the Emirate, such as here in Wadi Tarabat (Jebel Hafit)

12 Figure 9. Euphorbia larica (Euphorbiaceae) is restricted to alluvial plains and rocky slopes in the eastern part of the Emirate, and is common on Jebel Hafit. 3. Vegetation and flora 3.1. Vegetation The vegetation of the UAE, as with the Arabian Peninsula in general, has received relatively little attention. Initial or partial attempts to classify the vegetation of the Emirate have been carried out by Western (1989), Roshier et al. (1996) and Böer & Gliddon (1997). Useful as they are, they remain incomplete, and a more rigorous approach is required taking the whole country and if possible adjacent regions into consideration. The lack of knowledge on the vegetation can possibly be attributed to a number of reasons, including general problems associated with regions with sparse vegetation cover, the paucity of suitable indicator species for classification, the lack of experts, problems in the past with accessibility to many parts of the desert and also the climate. For instance, the vegetation may appear dead in dry years, when it is in fact dormant, but species in a state or dormancy can be extremely difficult to identify without experience. Also, annual species and short-lived perennials can remain as seed in the ground for decades, germinating and producing visible plants only under favourable rainfall conditions. These species are even more difficult to record

13 In general, vegetation cover is sparse due to the harsh environmental conditions. Cover values for most inland vegetation types are less than 5 %, usually ranging from 1 to 2 % Flora On the basis of present information, obtained from a variety of sources as well as our own fieldwork, the UAE is home to around 800 species of higher plants which are either native or have become naturalised. Of these, roughly 400 species are known for Abu Dhabi Emirate, and they represent 255 genera and 62 families. Apart from ferns and the genus Ephedra, all native plants are angiosperms. In terms of species number, the best represented families are the Poaceae (69), Fabaceae (34), Asteraceae (28) and Chenopodiaceae (27). Some families with fewer species, such as the Cyperaceae (e.g. Cyperus conglomeratus), Mimosaceae (e.g. Acacia tortilis, Prosopis cineraria), Verbenaceae (e.g. Avicennia marina) and Zygophyllaceae (e.g. Zygophyllum qatarense) are of particular ecological significance due the dominance of individual representatives in the vegetation. Figure 10. The Poaceae (true grasses) are the most species-rich family in the Emirate, but some species, such as Halopyrum mucronatum (see also Figure 3), are very rare and local. Taxonomic confusion surrounds a number of groups in the Emirate and region as a whole. Examples of more common critical groups in Abu Dhabi Emirate include the genera Tamarix, Tribulus and Zygophyllum. Only detailed research by specialists will help shed light on the true status of these taxa. Some footnotes are given in the species list (Appendix 1) where there are marked contrasts to prevailing opinions. Most perennial species in the flora of Abu Dhabi are xerophytes, i.e. plants that can

14 Figure 11. Leptadenia pyrotechnica (Asclepiadaceae) is a good example of a perennial shrub which soon loses its leaves to reduce transpirational water-loss. Photosynthesis is carried out by the whip-like branches. Figure 13. Cistanche tubulosa (Orobanchaceae) is a common parasite in the northern part of the Emirate. Its host plants include various chenopods and Zygophyllum qatarense. Figure 12. Cynomorium coccineum (Cynomoriaceae) is a widespread parasite, particularly in coastal areas

15 grow in very dry conditions and are able to withstand long periods of drought. Typical adaptations include the ability to store large amounts of water in their stems and leaves (succulents), waxy, reflective leaves, reduction of leaf size to avoid water loss through transpiration (see Figure 11) and deep-rooting systems. Halophytes (plants that are adapted morphologically and/or physiologically to grow in salt-rich soils and salt-laden air) and psammophytes (plants adapted to grow in loose, often nutrientpoor sand) are also important elements of the flora. Desert annuals, i.e. plants that complete their life-cycle rapidly during periods when conditions are favourable for growth and reproduction, surviving extended periods of drought as seed, are typical stress-evaders, and constitute a significant part of the flora of the Emirate. In contrast, hygrophytes (plant that are adapted morphologically and / or physiologically to growing in water or very wet environments) are barely represented. There are only several parasitic plant species in the Emirate, and two of these are shown in Figures 12 and 13. The relationship between the occurrence of certain dominant perennial desert plants and soil parameters, such as salinity, grain size and surface hardness, has been investigated by Böer & Sargeant (1998). Some of these species are undoubtedly useful indicators of specific soil conditions, but more in-depth studies are required Biogeography A first phytogeographical division of the Middle East was produced by Zohary (1973), which more recently has been slightly modified (Léonard, 1989). In accordance with the latter author, Abu Dhabi Emirate lies within the Saharo-Sindian regional zone. This phytochorion can be further divided into two subzones, which, however, are not sharply delimited. The Nubo-Sindian local centre of endemism is restricted to a narrow coastal belt in the Emirate, whereas inland areas fall within the Arabian regional subzone. The Nubo- Sindian phytochorion corresponds to the Sudanian region of Zohary (1973), whereas the Arabian regional subzone covers largely the same area as Zohary's Saharo- Arabian region. Typical genera of the Arabian regional subzone include, amongst others, Medicago, Ononis, Spergularia and Silene. These are largely derived from a Mediterranean stock, with Astragalus, Calligonum and various chenopods as Irano-Turanian derivatives

16 Figure 14. Lasiurus scindicus (Poaceae) occurs mainly in coastal areas, occasionally further inland such as near Jebel Hafit. Characteristic of the Nubo-Sindian local centre of endemism, which is well developed in the east of the Emirate, extending some way inland, is a xero-tropical vegetation in which trees play an important role. In Abu Dhabi Emirate and eastern Arabia in general, Acacia tortilis is a prominent element restricted to this region. Other characteristic taxa include Calotropis procera, Capparis spp., Cleome spp., Cymbopogon spp., Halopeplis perfoliata, Indigofera spp., Lasiurus scindicus (Figure 14), Launaea spp., Leptadenia pyrotechnica (see Figure 11), Panicum turgidum, Pennisetum divisum, Periploca aphylla, Salvadora persica and Tephrosia spp. Figure 15. Prosopis cineraria ( ghaf ) is a good example of an Omano-Makranian element, and is restricted to the eastern part of the UAE. In Abu Dhabi, it occurs mainly on low sand dunes, especially in the Sweihan - Al Hayer - Al Ain - Al Khatam area

17 Figure 16. Haloxylon persicum (Chenopodiaceae) is of considerable biogeographical interest, as the species is restricted to a narrow coastal belt immediately to the south and south-west of Abu Dhabi island. The stands here, covering an area of ca km 2, are of outstanding conservation value (see Aspinall & Hellyer, 2003; Brown & Böer, 2004). Furthermore, many taxa in the Emirate show floristic links to the Makran in southern Iran and also to Pakistan. These are referred to as Omano-Makranian elements (Kürschner, 1986). The natural western distribution limits of a number of these species are the Hajar Mountains, including Jebel Hafit. Good examples include Gaillonia aucheri, Physorrhynchus chamaerapistrum, Pseudogaillonia hymenostephana and Tephrosia apollinea. Others, for example, Prosopis cineraria ('ghaf' - Figure 15), have managed to extend their natural range slightly further westwards, not quite reaching Abu Dhabi Island. Cornulaca aucheri, Salsola drummondii and Sphaerocoma aucheri occur as far west as the Saudi Arabian border, or even beyond. Within the Emirate, even away the mountains, there are subtle differences in the climatic conditions which have a marked effect on the distribution of plant species. The flora of coastal white dunes is a good example, which becomes increasingly poorer in species from Dubai to Abu Dhabi island. This is probably due to a slight decrease in rainfall and possibly marginally higher winter temperatures towards the south-west

18 4. Threats to the vegetation and flora The majority of the population of Abu Dhabi lives in the larger towns and cities. Extensive tracts of the natural desert environment are therefore virtually uninhabited. However, this does not mean that there have been no anthropogenic impacts in these areas. Böer (1999) has highlighted those factors that are the prime cause of habitat loss and degradation in the Emirate. Overgrazing by ever-expanding livestock numbers has had a serious effect on the natural vegetation, as underlined by Böer & Norton (1996), with palatable species such as perennial grasses and dwarf shrubs being particularly badly hit. In combination with the recent cycle of dry years, some of these species are likely to become severely reduced in their population size for years. A good example of a former dominant species in the north-eastern part of the Emirate that has all but disappeared from its primary habitat due to overgrazing is Rhanterium epapposum, a species of sand sheets (see Western, 1989). The decline of this and other species has not been without repercussions, as they often fulfil important ecological roles. In the case of Rhanterium, the plants stabilise sand sheets and therefore prevent certain aspects of desertification, in particular soil erosion. Furthermore, other species, especially insects, that are associated with, or even dependent on the plants are also likely to have suffered declines in their populations. Conversely, there has been an increase in non-palatable species such as Zygophyllum qatarense and Rhazya stricta. Communities dominated by these perennials tend to be less diverse. The recent trend towards forestry and agricultural development has also had negative impacts, both directly and indirectly, on the natural environment in some areas. Apart from the direct effects of habitat loss and fragmentation, groundwater abstraction and the ensuing lowering of the groundwater table have had serious consequences for the natural vegetation locally, leading, for instance, to the death of ghaf (Prosopis cineraria) trees. Coastal areas have suffered enormously in recent years, mostly from massive development. Urgent action is required to protect some of the larger remaining areas with intact vegetation from ultimate destruction

19 Acknowledgements We would like to thank ERWDA management for support of this work. Dr. Richard Perry (ERWDA) kindly commented on a draft version of this manuscript. We are also grateful to Dr. Abdul Nasser Al Gifri (Zayed Complex for Herbal Research and Traditional Medicine (ZCHRTM)) for information on a number of species and access to the ZCHRTM Herbarium. We are also grateful to Rashid Al Mansouri for expert desert driving. References Aspinall, S. & Hellyer, P. (2003): Abu Dhabi s Dew Forest. - Tribulus 13: Böer, B. (1997): An introduction to the climate of the United Arab Emirates. - Journal of Arid Environments 35: Böer, B. (1999): Ecosystems, anthropogenic impacts and habitat management techniques in Abu Dhabi. - Paderborner Geographische Studien 12: Böer, B. & Gliddon, D. (1997): The geography and land forms of Abu Dhabi. - ERWDA Internal Research Report pp. Böer, B. & Norten, J. (1996): Vegetation rehabilitation in an enclosure in Abu Dhabi. - Fresenius Environmental Bulletin 5: Böer, B. & Sargeant, D. (1997): Desert perennials as plant and soil indicators in Eastern Arabia. - ERWDA Internal Research Report pp. Brown, G. (2004): The sabkha vegetation of the UAE. - In: Sabkha Ecosystems Vol. 3. Tasks for Vegetation Science. Kluwer, Dordrecht. In press. Brown, G. & Böer, B. (2004): Major terrestrial habitat types, vegetation and flora of the UAE. - In: Natural Emirates. In press. Deil, U. (2000): Halophytic vegetation along the Arabian coast - azonal or linked to climatic zones? - Phytocoenologia 30: Jongbloed, M., Western, R.A. & Böer, B. (2000): Annotated check-list of plants in the U.A.E. - Zodiac Publishing, Dubai. 91 pp. Jongbloed, M.V.D, Feulner, G.R., Böer, B. & Western, A.R. (2003): The Comprehensive Guide to the Wildflowers of the UAE. - ERWDA, Abu Dhabi. 576 pp. Kürschner, H. (1986): Omanisch-makranische Disjunktionen: Ein Beitrag zur pflanzengeographischen Stellung und zu den florengenetischen Beziehungen Omans. - Botanische Jahrbücher für Systematik 106: Mandaville, J.P. (1990): Flora of Eastern Saudi Arabia. - Kegan Paul International. 482 pp. Middleton, N. & Thomas, D. (1997): World Atlas of Desertification. - UNEP/Arnold. 182 pp. Raunkiaer, C. (1934): The Life Forms of Plants and Statistical Plant Geography. - Clarendon Press, Oxford. Roshier, D.A., Böer, B.B. & Osborne, P.E. (1996): Vegetation of Abu Dhabi and a preliminary classification of its plant

20 associations. - In: Osborne, P.E. (ed.): Desert Ecology of Abu Dhabi. Pisces Publications. pp Western, A.R. (1989): The Flora of the United Arab Emirates An Introduction. - United Arab Emirates University. 188 pp. Zohary, M. (1973): Geobotanical Foundations of the Middle East. - Gustav Fischer Verlag, Stuttgart. 739 pp

21 Appendix 1. Checklist of the vascular flora of Abu Dhabi Emirate. The list contains all native and naturalised species currently known to occur in Abu Dhabi Emirate. Abbreviations of life-forms (in accordance with Raunkiaer, 1934) and habitats are given at the end. Species Life-form Habitat Coa Sab Dun Pla Roc Wat Oas Urb Off Acanthaceae 1 Blepharis ciliaris (L.) B.L. Burtt Ch x 2 Peristrophe paniculata (Forssk.) Brummit Th x Adiantaceae 3 Chelianthes sp. He x Aizoaceae 4 Aizoon canariense L. Th x x x 5 Mesembryanthemum nodiflorum L. Th x 6 Sesuvium portulacastrum L. Ch x 7 Sesuvium sesuvioides (Fenzl) Verde Ch x 8 Sesuvium verrucosum Raf. Ch x 9 Zaleya pentandra (L.) C. Jeffrey Th / Ch x x Amaranthaceae 10 Achyranthes aspera L. Ch x 11 Aerva javanica (Burm. f.) Juss. ex Schul. Ch x x 12 Amaranthus albus L. Th x 13 Amaranthus graecizans L. Th x 14 Amaranthus hybridus L. Th x x 15 Amaranthus spinosus L. Th x 16 Amaranthus viridis L. Th x 17 Digera muricata (L.) Mast. Th x

22 Species Life-form Habitat Coa Sab Dun Pla Roc Wat Oas Urb Off Apiaceae 18 Ammi majus L. Th x x 19 Ducrosia anethifolia (DC.) Boiss. Ch x x x Apocynaceae 20 Nerium oleander L. Ph x x 21 Rhazya stricta Decne. Ch x x Arecaceae 22 Nanorrhops ritchieana (Griffith) Aitch. Ch x 23 Phoenix dactylifera L. Ph x x Aristolochiaceae 24 Aristolochia bracteolata Lam. Ch / Th x x Asclepiadaceae 25 Calotropis procera (Aiton) W.T. Aiton Ph x x 26 Caralluma arabica N.E. Br. Ch x 27 Glossonema varians (Stocks) J.D. Hook. Th / He x 28 Leptadenia pyrotechnica (Forssk.) Decne. Ph x x x 29 Pentatropis nivalis (J.F. Gmel.) Li x 30 Pergularia tomentosa L. Li x x x 31 Periploca aphylla Decne. Ch x Asphodelaceae 32 Asphodelus tenuifolius (Cav.) Baker Ge x x Asteraceae 33 Anvillea garcinii (Burm. f.) DC. Ch x x 34 Asteriscus hierochunticus (Michon) Wik. Th x

23 Species Life-form Habitat Coa Sab Dun Pla Roc Wat Oas Urb Off 35 Atractylis carduus (Forssk.) C. Chr. Th x x x 36 Carthamus oxycanthus M. Bieb. Th x 37 Carthamus tinctorius L. Th x 38 Centaurea pseudosinaica Czerep. Th x x 39 Conyza bonariensis (L.) Cronq. Th x 40 Echinops sp. (a) He x 41 Filago desortorum Pomel Th x 42 Flaveria trinervia (Spreng.) Mohr Th x x 43 Gymnarrhena micrantha Desf. Th x 44 Helichrysum glumaceum DC. Ch x 45 Helichrysum makranicum (Rech. f. & Esfand.) Rech. f. He x 46 Ifloga spicata (Forssk.) Willd. Th x 47 Iphiona aucheri (Boiss.) A. Anders Ch x x 48 Iphiona horrida Boiss. Ch x 49 Iphiona scabra Decne. Ch x 50 Koelpinia linearis Pall. Th x x x 51 Launaea capitata (Spreng.) Dandy Th x 52 Launaea mucronata (Forssk.) Muschl. Ch x 53 Launaea nudicaulis (L.) Hook. f. Ch x 54 Launaea procumbens (Roxb.) Ram. & Raj. Ch x x 55 Launaea spinosa (Forssk.) Sch. Bip. Ch x 56 Phagnalon viridifolium Decne. Ch x 57 Pluchea dioscoridis (L.) DC. Ch x 58 Pseudognaphalium luteoalbum (L.) H. & B. Ch x 59 Pulicaria edmondsonii Gamal-Eldin Ch x 60 Pulicaria glutinosa Jaub. & Spach Ch x x 61 Pulicaria undulata (L.) C.A. Meyer Ch x 62 Reichardia tingitana (L.) Roth Ch x 63 Rhanterium epapposum Oliv. Ch x x x 64 Scorzonera tortuosissima Boiss. Ch x 65 Senecio flavus (Decne.) Sch. Bip. Th x

24 Species Life-form Habitat Coa Sab Dun Pla Roc Wat Oas Urb Off 66 Senecio glaucus L. ssp. coronopifolius (Maire) Al. Th x 67 Sonchus oleraceus L. Th x 68 Urospermum picroides (L.) F.W. Schmidt Th x 69 Vernonia arabica F.G. Davies Ch x Avicenniaceae 70 Avicennia marina (Forssk.) Vierh. Ph x Boraginaceae 71 Arnebia hispidissima (Lehm.) DC. Th x x 72 Echiochilon jugatum I.M. Johnst. Ch x 73 Echiochilon persicum (Burm. f.) I.M. Johnst. Ch x 74 Echiochilon thesigeri I.M. Johnst. Ch x 75 Heliotropium bacciferum Forssk. Ch x x x x 76 Heliotropium calcareum Stocks. Ch x x x 77 Heliotropium curassavicum L. Ch x 78 Heliotropium digynum (Forssk.) Ch x 79 Heliotropium lasiocarpum Fisch. & Mey. Th x 80 Moltkiopsis ciliata (Forssk.) I.M. Johnst. Ch x x 81 Trichosdesma enetotrichum R.R. Mill Th x Brassicaceae 82 Anastatica hierochuntica L. Th x x x 83 Brassica tournefortii Gouan Th x 84 Capsella bursa-pastoris (L.) Medik. Th x 85 Cardaria draba (L.) Desv. Th x 86 Coronopus didymus (L.) Sm. Th x x 87 Diplotaxis harra (Forssk.) Boiss. Th x 88 Eremobium aegyptiacum (Spreng.) Boiss. Th x 89 Eruca sativa Mill. Th x

25 Species Life-form Habitat Coa Sab Dun Pla Roc Wat Oas Urb Off 90 Farsetia aegyptia Turra Ch x 91 Farsetia linearis Decne. ex Boiss. Ch x x x 92 Farsetia longisiliqua Decne. Ch x 93 Farsetia stylosa R. Br. Th / Ch x x 94 Malcomia africana (L.) R. Br. Ch x 95 Morettia parviflora Boiss. Th x x 96 Physorrhynchus chamaerapistrum Boiss. Ch x x 97 Rorippa palustris (L.) Besser Th x 98 Savignya parviflora (Delile) Webb Th x x x 99 Sisymbrium erysimoides Desf. Th x x Caesalpiniaceae 100 Senna italica Mill. Ch x x x Capparaceae 101 Capparis cartilaginea Decne. Ch x x 102 Capparis spinosa L. Ch x x 103 Cleome amblyocarpa Barr. & Murb. Th / Ch x x 104 Cleome austroarabica D.F.C. & Lam. ssp. muscatensis D.F.C. & Lam. Ch x 105 Cleome brachycarpa Vahl ex DC. Ch x x 106 Cleome noeana Boiss. Th / Ch x 107 Cleome rupicola Vicary Ch x x 108 Dipterygium glaucum Decne. Ch x x Caryophyllaceae 109 Cometes surattensis L. Th x 110 Dianthus cyri Fisch. & C.A. Mey. Th x 111 Gymnocarpos decandrus Forssk. Ch x x 112 Gypsophila bellidifolia Boiss. Th x x

26 Species Life-form Habitat Coa Sab Dun Pla Roc Wat Oas Urb Off 113 Herniaria hemistemon J. Gay Th x x x 114 Paronychia arabica (L.) DC. Th x x 115 Polycarpaea repens (Forssk.) Asch. & Sch. Ch x x x 116 Polycarpaea spicata Wight ex Arn. Th x x 117 Sclerocephalus arabicus Boiss. Th x x x 118 Silene arenosa C. Koch Th x 119 Silene villosa Forssk. Th x 120 Spergula fallax (Lowe) E.H.L. Krause Th x x x 121 Spergularia diandra (Guss.) Boiss. Th x 122 Spergularia marina (L.) Bessler Th x x 123 Sphaerocoma aucheri Boiss. Ch x x x 124 Stellaria media (L.) Vill. Th x Chenopodiaceae 125 Agriophyllum minus Fisch. & C.A. Mey. Th x x 126 Anabasis setifera Moq. Ch x x x 127 Arthrocnemum macrostachyum (Moric.) K. Koch Ch x 128 Atriplex leucoclada Boiss. Ch x 129 Bassia muricata (L.) Asch. Th / Ch x 130 Beta vulgaris L. Th x 131 Bienertia cycloptera Bunge ex Boiss. Th x x 132 Chenopodium album L. Th x 133 Chenopodium murale L. Th x x x 134 Cornulaca arabica Botsch. (b) Ch x 135 Cornulaca aucheri Moq. Th / Ch x 136 Cornulaca monacantha Delile Ch x x x 137 Halocnemum strobilaceum (Pall.) M. Bieb. Ch x 138 Halopeplis perfoliata (Forssk.) Bun ex As. Ch x x 139 Halothamnus bottae Jaub. & Spach Ch x x 140 Haloxylon persicum Bunge Ph x

27 Species Life-form Habitat Coa Sab Dun Pla Roc Wat Oas Urb Off 141 Haloxylon salicornicum (Mo.) Bun. ex Boiss. Ch x x x 142 Salicornia europaea L. Th x 143 Salsola arabica Botsch. (c) Ch x 144 Salsola cyclophylla Baker Ch x 145 Salsola drummondii Ulbr. Ch x x x 146 Salsola imbricata Forssk. Th / Ch x x x x x 147 Salsola rubescens Franch. Ch x x x x 148 Salsola schweinfurthii Solms-Laub. Ch x 149 Salsola tetrandra Forssk. Ch x 150 Seidlitzia rosmarinus Ehrenb. ex Bunge Ch x x x 151 Suaeda aegyptiaca (Hassel.) Zoh. Th / Ch x x x 152 Suaeda vermiculata Forssk. ex J.F. Gmel. Ch x x x Cistaceae 153 Helianthemum kahiricum Delile Ch x 154 Helianthemum lippii (L.) Dum. Cours. Ch x x x x x Convolvulaceae 155 Convolvulus acanthocladus Boiss. Ch x 156 Convolvulus arvensis L. Ch x x 157 Convolvulus cephalopodus Boiss. Ch x x 158 Convolvulus glomeratus Choisy Ch x 159 Convolvulus pilosellifolius Desr. Ch x x 160 Convolvulus prostratus Forssk. Ch x x 161 Convolvulus virgatus Boiss. Ch x x x 162 Cressa cretica L. Ch x x x 163 Cuscuta planiflora Ten. Li (P) x x x 164 Ipomoea aquatica Forssk. Th x

28 Species Life-form Habitat Coa Sab Dun Pla Roc Wat Oas Urb Off Cucurbitaceae 165 Citrullus colocynthis (L.) Schrad. Th / He x 166 Cucumis prophetarum L. Th x x Cynomoriaceae 167 Cynomorium coccineum L. Ch (P) x x x Cyperaceae 168 Bolboschoenus maritima (L.) Palla Ge x x 169 Cladium mariscus (L.) Pohl Ge x 170 Cyperus arenarius Retz. Ge x x 171 Cyperus conglomeratus Rottb. Ge x 172 Cyperus laevigatus L. Ge x 173 Cyperus rotundus L. Ge x x x 174 Fimbrystilis sp. (d) He x Ephedraceae 175 Ephedra foliata Boiss. ex C.A. Mey. Li x x Euphorbiaceae 176 Chrozophora oblongifolia (Delile) Spreng. Ch x x 177 Euphorbia granulata Forssk. Th x x x 178 Euphorbia helioscopia L. Th x 179 Euphorbia heterophylla L. Th x 180 Euphorbia hirta L. Th x 181 Euphorbia indica Lam. Th x 182 Euphorbia larica Boiss. Ch x x 183 Euphorbia peplus L. Th x 184 Euphorbia prostrata Ait. Th x 185 Euphorbia serpens Kunth Th x 186 Phyllanthus rotundifolius Willd. Th x

29 Species Life-form Habitat Coa Sab Dun Pla Roc Wat Oas Urb Off 187 Ricinus communis L. Ph x x Fabaceae 188 Alhagi graecorum Boiss. Ph x x 189 Argyrolobium roseum (Cam.) Jaub. & Spach. Th x x 190 Astragalus annularis Forssk. Th x x 191 Astragalus eremophilus Boiss. Th x 192 Astragalus hauarensis Boiss. Th x 193 Astragalus schimperi Boiss. Th x 194 Crotalaria aegyptiaca Benth. Ch x x x 195 Crotalaria persica (Burm. f.) Merrill Ch x 196 Hippocrepis areolata Desv. Th x x 197 Hippocrepis constricta Kunze Th x x x 198 Indigofera arabica Burm. f. Ch x x x 199 Indigofera argentea L. Ch x 200 Indigofera articulata Gouan Ch x 201 Indigofera caerulea Roxb. Ch x 202 Indigofera colutea (Burm. f.) Merrill Ch x 203 Indigofera intricata Boiss. Ch x 204 Indigofera oblongifolia Borssk. Ch x x 205 Lotononis platycarpa (Viv.) Pic.-Serm. Th x x x 206 Lotus garcinii DC. Ch x 207 Lotus halophilus Boiss. & Spruner Th x x 208 Lotus sp. (e) Ch x 209 Medicago laciniata (L.) Mill. Th x 210 Medicago polymorpha L. Th x 211 Melilotus alba Medik. Th x 212 Melilotus indica (L.) All. Th x 213 Ononis serrata Forssk. Th x 214 Rhynchosia minima (L.) DC. Ch x

30 Species Life-form Habitat Coa Sab Dun Pla Roc Wat Oas Urb Off 215 Rhynchosia schimperi Hochst. & Boiss. Ch x 216 Taverniera glabra Boiss. Ch x x 217 Taverniera lappacea (Forssk.) DC. Ch x 218 Taverniera spartea (Burm. f.) DC. Ch x 219 Tephrosia apollinea (Delile) DC. Ch x x x 220 Tephrosia nubica (Boiss.) Baker Ch x x 221 Tephrosia uniflora Pers. Ch x 222 Trigonella hamosa L. Th x x Frankeniaceae 223 Frankenia pulverulenta L. Th x x x Geraniaceae 224 Erodium laciniatum (Cav.) Willd. Th x x 225 Erodium malacoides (L.) L'Hér. Th x 226 Geranium mascatense Boiss. Th x x 227 Monsonia heliotropioides (Cav.) Boiss. Ch x 228 Monsonia nivea (Decne.) Webb Ch x x Hydrocharitaceae 229 Halophila stipulacea (Forssk.) Aschers Ch x Juncaceae 230 Juncus rigidus Desf. Ge x x Lamiaceae 231 Lavandula subnuda Benth. Ch x 232 Leucas inflata Benth. Th x 233 Salvia aegyptiaca L. Th / Ch x

31 Species Life-form Habitat Coa Sab Dun Pla Roc Wat Oas Urb Off 234 Salvia macilenta Boiss. Ch x x 235 Salvia spinosa L. He x 236 Teucrium stocksianum Boiss. Ch x Liliaceae 237 Dipcadi biflorum Ghaz. Ge x x 238 Dipcadi erythraeum Webb & Berth. Ge x x Lythraceae 239 Lawsonia inermis L. Ph x x Malphigiaceae 240 Acridocarpus orientalis A. Juss. Ph x Malvaceae 241 Abutilon pannosum (Forst. f.) Schlecht. Ch x 242 Althaea ludwigii L. Th x 243 Hibiscus micranthus L. Ch x 244 Malva parviflora L. Th x x x x Menispermeaceae 245 Cocculus pendulus (J.R. & G. Forst.) Diels Li x Mimosaceae 246 Acacia ehrenbergiana Hayne Ph x x 247 Acacia nilotica (L.) Willd. ex Delile Ph x x 248 Acacia tortilis (Forssk.) Hayne Ph x x x 249 Prosopis cineraria (L.) Druce Ph x x x 250 Prosopis farcta (Banks & Sol.) Mac. Ch x x

32 Species Life-form Habitat Coa Sab Dun Pla Roc Wat Oas Urb Off 251 Prosopis juliflora (Sw.) DC. Ph x x x Molluginaceae 252 Limeum arabicum Friedr. Ch x 253 Limeum obovatum Vicary Th x x x Moraceae 254 Ficus johannis Boiss. ssp. johannis Ph x Moringaceae 255 Moringa peregrina (Forssk.) Fiori Ph x Neuradaceae 256 Neurada procumbens L. Th x x x Nyctaginaceae 257 Boerhavia elegans Choisy Ph x Orobanchaceae 258 Cistanche tubulosa (Schenk) Wight Ge (P) x x 259 Orobanche sp. Ge (P) x Oxalidaceae 260 Oxalis corniculata L. Th x x Plantaginaceae 261 Plantago amplexicaulis Cav. Th x 262 Plantago boissieri Hausskn. & Bornm. Th x x 263 Plantago ciliata Desf. Th x x x 264 Plantago ovata Forssk. Th x

33 Species Life-form Habitat Coa Sab Dun Pla Roc Wat Oas Urb Off Plumbaginaceae 265 Dyerophytum indicum (Gib. ex Wig.) Kun. Ch x 266 Limonium axillare (Forssk.) Kuntze Ch x x 267 Limonium carnosum (Boiss.) O. Kuntze Ch x x Poaceae 268 Aeluropus lagopoides (L.) Trin. He x x x 269 Aeluropus littoralis (Gouan) Parl. He x 270 Aristida abnormis Chiov. Th x 271 Aristida adscensionis L. Th x x 272 Arundo donax L. Ch x x x 273 Avena fatua L. Th x 274 Avena sterilis Gill & Magne Th x 275 Brachiaria ramosa (L.) Stapf Th x 276 Brachiaria reptans (L.) Gard. & C.E. Hub. Th x x 277 Cenchrus ciliaris L. He x x x x 278 Cenchrus echinatus L. Th x 279 Cenchrus pennisetiformis Hochst. & Steud. Th x x 280 Cenchrus setigerus Vahl. He x x x 281 Centropodia forsskaolii (Vahl) Cope Th / He x 282 Centropodia fragilis (Guin. & Sauv.) Cope He x 283 Chloris barbata Swartz Th x x 284 Chloris gayana Kunth. He / Ge x 285 Chloris virgata Swartz Th x 286 Coelachyrum brevifolium (Benth.) Bor Th x 287 Coelachyrum piercii (Benth.) Bor He x 288 Cymbopogon commutatus (Steud.) Stapf He x 289 Cymbopogon schoenanthus (L.) Spreng. He x

34 Species Life-form Habitat Coa Sab Dun Pla Roc Wat Oas Urb Off 290 Cynodon dactylon (L.) Pers. Ge x x x 291 Dactyloctenium aegyptium (L.) P. Beauv. Th x x x 292 Dactyloctenium scindicum Boiss. Ge x 293 Dichanthium annulatum (Forssk.) Stapf. He x 294 Dichanthium foveolatum (Delile) Roberty He x x x 295 Digitaria sanguinalis (L.) Scop. Th x x 296 Echinochloa colona (L.) Link Th x x 297 Echinochloa crus-galli (L.) P. Beauv. Th x x 298 Eragrostis barrelieri Daveau Th x x x 299 Eragrostis cilianensis (All.) Vign. Th x x 300 Eragrostis ciliaris (L.) R. Br. Th x x 301 Eragrostis papposa R. & J. Steud. Th x 302 Eragrostis pilosa (L.) P. Beauv. He x 303 Eragrostis tenella (L.) P. Beauv. Th x x 304 Halopyrum mucronatum (L.) Stapf Th x 305 Hordeum glaucum Steud. Th x 306 Hyparrhenia hirta (L.) Stapf He x x 307 Imperata cylindrica (L.) Beauv. He x x 308 Lasiurus scindicus Henrard He x x 309 Latipes senegalensis Kunth He x 310 Lolium rigidum Gaudin Th x 311 Ochtochloa compressa (Forssk.) Hilub He x 312 Panicum antidotale Retz. He x 313 Panicum turgidum Forssk. He x x x 314 Paspalum vaginatum Sw. Ch x 315 Pennisetum divisum (J.F. Gmel.) Henrard He x x x 316 Pennisetum setaceun (Forssk.) Chiov. He x 317 Phalaris minor Retz. Th x 318 Phragmites australis (Cav.) Trin. ex Steud. He / Ge x x 319 Poa annua L. Th x

35 Species Life-form Habitat Coa Sab Dun Pla Roc Wat Oas Urb Off 320 Polypogon monspeliensis (L.) Desf. Th x x x 321 Rostraria cristata (L.) Tzvelev Th x 322 Saccharum griffithii Munro ex Benth. Ch x 323 Saccharum ravennae (L.) Murr. Ch x 324 Schismus barbatus (L.) Thell. Th x x 325 Setaria verticillata (L.) P. Beauv. Th x 326 Setaria viridis (L.) P. Beauv. Th x 327 Sphenopus divaricatus (Gouan) Reichb. Th x 328 Sporobolus ioclados (Nees ex Trin.) Nees Ge x x 329 Sporobolus spicatus (Vahl) Kunth Ge x x x x 330 Stipa capensis Thunb. Th x x x 331 Stipagrostis ciliata (Desf.) de Winter He x x x 332 Stipagrostis obtusa (Delile) Nees (f) He x 333 Stipagrostis paradisea (Edgew.) de Winter He x 334 Stipagrostis plumosa (L.) Mun. ex T. And. He x x x 335 Stipagrostis sokotrana (Vierh.) de Winter He x 336 Stipagrostis sp. (g) He x 337 Tetrapogon villosus Desf. He x 338 Tragus racemosus (L.) All. Th x 339 Tricholaena teneriffae (L. f.) Parl. He x 340 Triraphis pumilio R. Br. Th x x Polygalaceae 341 Polygala erioptera DC. Th x 342 Polygala irregularis Boiss. Th / Ch x Polygonaceae 343 Calligonum comosum L'Her. Ph x x 344 Calligonum crinitum Boiss. ssp. arabicus (Sos.) Sos. Ph x 345 Emex spinosa (L.) Campd. Th x x x

36 Species Life-form Habitat Coa Sab Dun Pla Roc Wat Oas Urb Off 346 Rumex dentatus L. Th / Ch x x 347 Rumex pictus Forssk. Th x 348 Rumex vesicarius L. Th x Portulacaceae 349 Portulaca olereaca L. Th x x 350 Portulaca quadrifida L. Th x Ranunculaceae 351 Ranunculus muricatus L. Th x Resedaceae 352 Ochradenus arabicus Chd., Hill. & Mill. Ch x x 353 Ochradenus aucheri Boiss. Th / Ch x 354 Ochradenus baccatus Del. He x 355 Oligomeris linifolia (Vahl) J.F. Macbr. Th x x x 356 Reseda arabica Boiss. Th x 357 Reseda aucheri Boiss. Th x x x Rhamnaceae 358 Ziziphus nummularia (Bur. f.) Wig. & Arn. Ch x 359 Ziziphus spina-christi (L.) Willd. Ph x x Rhizophoraceae 360 Rhizophora mucronata Lamk. Ph x Rubiaceae 361 Gaillonia aucheri (Guill.) Jaub. & Spach Ph x x 362 Galium setaceum Lam. Th x 363 Kohautia caespitosa Schinzl. Th / Ch x x x

37 Species Life-form Habitat Coa Sab Dun Pla Roc Wat Oas Urb Off 364 Pseudogaillonia hymenostephana Lin. Ch x Rutaceae 365 Haplophyllum tuberculatum (For.) A. Juss. Ch x x Salvadoraceae 366 Salvadora persica L. Ph x x x Sapindaceae 367 Dodonaea viscosa Jacq. Ph x Scrophulariaceae 368 Anticharis arabica Endl. Th x 369 Bacopa monnieri (L.) Pennell Ch x x 370 Lindenbergia arabica (Moore) Hartl Ch x 371 Lindenbergia indica O. Kuntze Ch x 372 Schweinfurthia papilionacea (Bur. f.) Boiss. Th x x 373 Scrophularia deserti Delile Ch x x Solanaceae 374 Lycium shawii Roem. & Schult. Ph x x x 375 Nicotiana plumbaginifolia Viv. Th x 376 Physalis minima L. Th x 377 Solanum nigrum L. Th x Tamaricaceae 378 Tamarix aphylla (L.) Karst. Ph x 379 Tamarix aucheriana (Decne.) Baum (h) Ph x 380 Tamarix mannifera (Ehrenb.) Bunge (h) Ph

38 Species Life-form Habitat Coa Sab Dn Pla Roc Wat Oas Urb Off 381 Tamarix nilotica (Ehrenb.) Bunge Ph x 382 Tamarix ramossissima Ledeb. (h) Ph x Tiliaceae 383 Corchorus depressus (L.) Stocks. Ch x x x 384 Corchorus trilocularis L. Th x 385 Grewia erythraea Schweinf. Ph x Typhaceae 386 Typha domingensis Pers. He x x Urticaceae 387 Forsskaolea tenacissima L. Th x x x x Verbenaceae 388 Phyla nodiflora (L.) Greene Ch x x 389 Vitex agnus-castus L. Ph x x Zygophyllaceae 390 Fagonia bruguieri DC. Ch x x x 391 Fagonia indica Burm. f. Ch x x x 392 Fagonia ovalifolia Hadidi Th x x 393 Seetzenia lanata (Willd.) Bullock Ch / He x x x 394 Tribulus arabicus Hosni s.l. (incl. T. omanense) Ch x x 395 Tribulus macropterus Boiss. Th x x 396 Tribulus pentandrus Forssk. Ch x x 397 Tribulus terrestris L. Th / Ch x x x x 398 Zygophyllum migahidii Hadidi (i) Ch x 399 Zygophyllum qatarense Hadidi (j) Ch x x x x x 400 Zygophyllum simplex L. Ch x x x x x x

39 Notes (a) Echinops sp. is listed for Jebel Hafit by Stuart & Stuart (1998). (b) Cornulaca arabica is probably a separate species from C. monacantha (c) A species which appears to be Salsola arabica was found by G. Brown on coastal sands west of Jebel Dhanna. (d) This common species in lawns (for instance in Abu Dhabi city) is possibly F. ferruginea (L.) Vahl. (e) An unidentifiable, possibly undescribed species of Lotus was found on Zirku in early 2004 by G. Brown, possibly the same species as Lotus sp. in Jongbloed (2003). (f) Stipagrostis obtusa is possibly S. foexiana (M. & W.) de Winter. (g) This species is possibly S. multinervia Scholz. (h) Tamarix species determined according to Mandaville (1990). (i) Zygophyllum migahidii is a distinct species which occurs in Jebel Hafit and offshore islands (e.g. Arzanah). (j) According to Deil (2000), Zygophyllum mandavillei Hadidi occurs only in southern Arabia. The widespread species occurring on interdunal plains in Abu Dhabi is best treated as Z. qatarense (see Brown, 2004). The status of the following species in Abu Dhabi Emirate is unclear: Erodium glaucophyllum (L.) L'Hér. Erodium neuradifolium Delile Stipagrostis hirtigluma (Steud. ex Trin. & Rupr.) de Winter Tribulus mollis Del.: A specimen closely fitting the description of this species was found in Dhafra. However, it is possible that it is an unknown variant of another Tribulus species. Habitats Life-Forms (in accordance with Raunkiaer, 1934) Coa Coastal saline habitats Ph Phanerophyte (woody perennial, perennating buds > 50 cm above the soil surface) Sab Sabkha Ch Chamaephyte (perennial, perennating buds distinctly above the soil surface, but < 50 cm ) Dun Inland sand sheets, dunes and mega-dunes He Hemicryptophyte (perennial, perennating buds on the soil surface) Pla Alluvial and interdunal plains Ge Geophyte (perennial, with subterranean storage tissues) Roc Mountains, rocky terrain and wadis Th Therophyte (annual plants which survive the unfavourable season as seed) Wat Inland water habitats Li Liana (vine-like plant which requires another plant species for support) Oas Oases, farmland and plantations (P) Parasite Urb Urban habitats Off Offshore islands