INTRODUCTION
⌅Myers (1990)Myers N. 1990. The biodiversity challenge: expanded hot-spots analysis. Environmentalist 10: 243-256. has recognized the Mediterranean basin as one of the richest biodiversity hotspots in the world. In fact, it is currently considered the world’s second largest Biodiversity Hotspot (IUCN 2022IUCN 2022. The IUCN Red List of Threatened Species. Version 2021-3. Website: https://www.iucnredlist.org [accessed: 15 Mar. 2022].). Geographically, it extends over more than 30 nations and encompasses important terrestrial habitats including coastal dunes, temperate forests, garrigue, maquis, grasslands, wetlands, and semi-desert zones. Its position at the crossroads between Africa, Asia and Europe has contributed to the diversity of ecosystems in the Mediterranean basin spanning arid, temperate and tropical biogeographical regions, distinguishing the basin from the more homogeneous areas to the north and south (Blondel & Aronson 1999Blondel J. & Aronson J. 1999. Biology and wildlife of the Mediterranean region. University Press, Oxford.; Zahran 2010Zahran M.A. 2010. Afro-Asian Mediterranean coastal lands. In Gilbert, F. ed., Climate-Vegetation: 1-103. Springer, Dordrecht). Consequently, the edaphic, climatic and topographical intricacy of the Mediterranean basin makes it exceptionally rich in biodiversity. It has been reported to include more than 25,000 species of flowering plants (Lihová & al. 2004Lihová J., Tribsch A. & Stuessy T.F. 2004. Cardamine apennina: a new endemic diploid species of the C. pratensis group (Brassicaceae) from Italy. Plant Systematics and Evolution 245: 69 - 92.; Zahran 2010Zahran M.A. 2010. Afro-Asian Mediterranean coastal lands. In Gilbert, F. ed., Climate-Vegetation: 1-103. Springer, Dordrecht; Vargas 2020Vargas P. 2020. The Mediterranean floristic region: high diversity of plants and vegetation types. In Goldstein M.I. & DellaSala D.A. (eds.), Encyclopedia of the World’s Biomes vol. 3: 602-616. Elsevier, Ashland.).
Endemism is an integral component of plant diversity in the Mediterranean region. According to the Med-Checklist (2016)Med-Checklist. 2016. A critical inventory of vascular plants of the circum-mediterranean countries. Website: http://ww2.bgbm.org/mcl/home.asp [accessed: 16 Mar. 2022]., about 63.5% of the recorded native species are endemic to the region (Greuter 1991Greuter W. 1991. Botanical diversity, endemism, rarity, and extinction in the Mediterranean area: an analysis based on the published volumes of Med-Checklist. Botanika Chronika 10: 63-79.; Heywood 2002Heywood V. 2002. The future of floristics in the Mediterranean region. Israel Journal of Plant Sciences 50(sup1): 5-13.). A main feature of endemism in the Mediterranean basin is that 60% of the endemic species are narrow endemics, i.e., they have a restricted distribution to one particular area well-defined within a small part of the basin (Thompson & al. 2005Thompson J.D., Lavergne S., Affre L., Gaudeul M. & Debussche M. 2005. Ecological differentiation of Mediterranean endemic plants. Taxon 54: 967-976.). Many of them are restricted to a single or a few localities in sandy areas, isolated mountain ranges, or islands of unusual soil or rocky ground, therefore the Mediterranean flora is brimming with narrow endemic taxa compared to other regions (Blondel & al. 2010Blondel J., Aronson J., Bodiou J.Y. & Boeuf G. 2010. The Mediterranean region: biological diversity in space and time. Oxford University Press, Oxford.; Zahran 2010Zahran M.A. 2010. Afro-Asian Mediterranean coastal lands. In Gilbert, F. ed., Climate-Vegetation: 1-103. Springer, Dordrecht).
Generally, islands (Whittaker & Fernández-Palacios 2007Whittaker R.J. & Fernández-Palacios J.M. 2007. Island Biogeography ed. 2. Oxford University Press, Oxford.; Kier & al. 2009Kier G., Kreft H., Lee T.M., Jetz W., Ibisch P.L., Nowicki C., Mutke J. & Barthlott W. 2009. A global assessment of endemism and species richness across island and mainland regions. Proceedings of the National Academy of Sciences 106: 9322-9327.) and coastal ecosystems are richer in plant endemism than inland areas (Abdelaal & al. 2020Abdelaal M., Fois M., Fenu G. & Bacchetta G. 2020. Biogeographical characterisation of Egypt based on environmental features and endemic vascular plants distribution. Applied Geography 119: a102208.). A characteristic feature of this region is the spatial isolation, where there are several islands, peninsulas, and high mountains (Vargas 2020Vargas P. 2020. The Mediterranean floristic region: high diversity of plants and vegetation types. In Goldstein M.I. & DellaSala D.A. (eds.), Encyclopedia of the World’s Biomes vol. 3: 602-616. Elsevier, Ashland.). Over 10,000 islands (and islets) are distributed across the Mediterranean Basin. Good examples are Sicily and Sardinia, which are the largest islands in the region, followed by Cyprus, Crete, Aegean Islands, Corsica, and Balearic Islands. Altitudinal taxa isolation is also remarkable. Hence, plate collisions between the three main peninsulas (Iberian, Italian, and Balkan) and the European plate in the Tertiary period resulted in mountains rising to around 2000 m elevation over southern Europe (Heywood 2002Heywood V. 2002. The future of floristics in the Mediterranean region. Israel Journal of Plant Sciences 50(sup1): 5-13.; Vargas 2020Vargas P. 2020. The Mediterranean floristic region: high diversity of plants and vegetation types. In Goldstein M.I. & DellaSala D.A. (eds.), Encyclopedia of the World’s Biomes vol. 3: 602-616. Elsevier, Ashland.). In addition, the region encompasses the Atlas, the largest mountain range in north Africa, which was uplifted in the Miocene as a result of orogenic movements (Babault & al. 2008Babault J., Teixell A., Arboleya M.L. & Charroud M. 2008. A late Cenozoic age for long-wavelength surface uplift of the Atlas Mountains of Morocco. Terra Nova 20: 102-107.). Further, with the exception of land proximity on the straits of Gibraltar and Tunisia-Sicily, the Mediterranean Sea’s east-west orientation itself has been a substantial geographical barrier for plant dispersal between north Africa and Europe (Rodríguez-Sánchez & Arroyo 2011Rodríguez-Sánchez F., Arroyo J. 2011. Cenozoic climate changes and the demise of Tethyan laurel forests: Lessons for the future from an integrative reconstruction of the past. Climate Change. Ecology and Systematics 78: 280.; Vargas 2020Vargas P. 2020. The Mediterranean floristic region: high diversity of plants and vegetation types. In Goldstein M.I. & DellaSala D.A. (eds.), Encyclopedia of the World’s Biomes vol. 3: 602-616. Elsevier, Ashland.). Consequently, most narrow endemics are found in southern Europe and north Africa either on islands or medium-high mountains (Vargas 2020Vargas P. 2020. The Mediterranean floristic region: high diversity of plants and vegetation types. In Goldstein M.I. & DellaSala D.A. (eds.), Encyclopedia of the World’s Biomes vol. 3: 602-616. Elsevier, Ashland.). Most parts of the Mediterranean basin have a high-level of rare and endemic taxa with small populations, the majority of which are endangered by many threats including fire, land use changes, habitat conversion and degradation (Cowling & al. 1996Cowling R.M., Rundel P.W., Lamont B.B., Arroyo M.K. & Arianoutsou M. 1996. Plant diversity in Mediterranean-climate regions. Trends in Ecology & Evolution 11: 362-366.; Rundel & al. 2018Rundel P.W., Arroyo M.T., Cowling R.M., Keeley J.E., Lamont B.B., Pausas J.G. & Vargas P. 2018. Fire and plant diversification in Mediterranean-climate regions. Frontiers in Plant Science 9: 851.). In fact, climatic instability and long-term change may also play roles in generating endemism, both by creating novel ecological opportunities for speciation and by producing shifting patterns of habitat fragmentation that are conducive to allopatric speciation, followed in some cases by secondary contact and hybridization (Harrison & Noss 2017Harrison S. & Noss R. 2017. Endemism hotspots are linked to stable climatic refugia. Annals of Botany 119: 207-214. and references therein).
The borderlines of the Mediterranean coastal strip in Egypt were modified by Boulos (1999-2005)Boulos L. 1999-2005. Flora of Egypt vols. 1-4. Al-Hadara Publishing, Cairo. to be stretched from the border with Libya, near Sallum, to Port Said. However, to the authors’ best knowledge, very few publications are available in the literature addressing the presence of a Mediterranean territory from Rosetta to Rafah. The last two decades witnessed intensive studies in the west Mediterranean coastal land, to cope with the devastation associated with the urbanization in this coastal strip (e.g., Halmy 2012Halmy M.W.A. 2012. Environmental risk assessment for habitats of the Egyptian northwestern coastal desert. Ph.D.dissertation, University of Idaho, Idaho.; Halmy & al. 2015aHalmy M.W.A., Gessler P.E., Hicke J.A. & Salem B.B. 2015a. Land use/land cover change detection and prediction in the north-western coastal desert of Egypt using Markov-CA. Applied Geography 63: 101-112., 2015bHalmy M.W., Gessler P.E. & Heneidy S.Z. 2015b. Implications of human induced changes on the distribution of important plant species in the northwestern coastal desert of Egypt. Renewable Energy and Sustainable Development 1: 243-263.; Halmy & Gessler 2015Halmy M.W.A. & Gessler P.E. 2015. The application of ensemble techniques for land-cover classification in arid lands. International Journal of Remote Sensing 36: 5613-5636.; Halmy 2019Halmy M.W.A. 2019. Assessing the impact of anthropogenic activities on the ecological quality of arid Mediterranean ecosystems (case study from the northwestern coast of Egypt). Ecological Indicators 101: 992-1003.; Halmy & al. 2019Halmy M.W.A., Fawzy M., Ahmed D.A., Saeed N.M. & Awad M.A. 2019. Monitoring and predicting the potential distribution of alien plant species in arid ecosystem using remotely-sensed data. Remote Sensing Applications: Society and Environment 13: 69-84.). It is unfortunate to report that Egypt had already lost over one hundred kilometers of its Mediterranean territory due to climate change, and human activities, especially the establishment of tourist summer resorts. As a result, it is now difficult to find any traces of the natural vegetation reported earlier in this region (El-Hadidi & Hosni 2000El-Hadidi M. & Hosni H. 2000. Conservation and threats. In El-Hadidi M.N. (ed.), Flora Aegyptiaca 1: 105-180. Palm Press, Cairo. ; Halmy 2012Halmy M.W.A. 2012. Environmental risk assessment for habitats of the Egyptian northwestern coastal desert. Ph.D.dissertation, University of Idaho, Idaho.; Halmy & al. 2015aHalmy M.W.A., Gessler P.E., Hicke J.A. & Salem B.B. 2015a. Land use/land cover change detection and prediction in the north-western coastal desert of Egypt using Markov-CA. Applied Geography 63: 101-112., 2015bHalmy M.W., Gessler P.E. & Heneidy S.Z. 2015b. Implications of human induced changes on the distribution of important plant species in the northwestern coastal desert of Egypt. Renewable Energy and Sustainable Development 1: 243-263.; Halmy 2019Halmy M.W.A. 2019. Assessing the impact of anthropogenic activities on the ecological quality of arid Mediterranean ecosystems (case study from the northwestern coast of Egypt). Ecological Indicators 101: 992-1003.; Halmy & al. 2019Haslam S.M., Sell P.D. & Wolseley P.A. 1977. A Flora of the Maltese Islands. Malta University Press, Msida.).
Djamali & al. (2012)Djamali M., Brewer S., Breckle S.W. & Jackson S.T. 2012. Climatic determinism in phytogeographic regionalization: a test from the Irano-Turanian region, SW and Central Asia. Flora-Morphology, Distribution. Functional Ecology of Plants 207: 237-249. indicated that Egypt is not part of the Mediterranean climate nor of the Mediterranean biogeographic region, due to the lack of any native arboreal Mediterranean taxa in Egypt. However, Wickens (1977)Wickens G.E. 1977. Some of the phytogeographical problems associated with Egypt. Cairo University Herbarium 7/8: 223-230. argued for the possibility of the presence of steppe maquis vegetation of the Ceratonia-Pistacion lentisci alliance (described by Zohary 1973Zohary M. 1973. Geobotanical foundations of the Middle East. G. Fischer, Stuttgart.) along the Egyptian Mediterranean coast, which is considered an evidence of the presence of a Mediterranean territory in Egypt. Moreover, Egypt is so close to floristically Mediterranean rich areas both to the west (Cyrenaic) and to the east, which could be an interesting place to study the interaction among the Mediterranean, the Tropical and the Saharo-Sindic floristic contingents. Therefore, it would play an interesting role as a melting pot among three (if not four if we consider also the Turanic contingent) floristic regions. The currently available data provide enough evidence for extending the Mediterranean territory in Egypt from Sallum, on the Egyptian-Libyan border, to Rafah, on the Egyptian-Palestinian border, as was elucidated by Zahran & al. (1985)Zahran M.A., El-Demerdash M.A. & Mashaly I.A. 1985. On the ecology of the deltaic coast of the Mediterranean Sea, Egypt. General survey. Proceeding of fourth Egyptian Botanical Society 4: 1392-1407..
Egypt has a long history in vegetation research, dating back to 1930s. Several regional studies on vegetation communities and floristic composition have been conducted. However, a compiled complete classification overview and a vegetation map of the Mediterranean region are still lacking. Consequently, this study aims to provide an authenticated database of the Mediterranean endemic plants of Egypt, analyze the checklist in terms of floristic diversity, geographical distribution, life forms, growth forms, flowering times and dispersal types.
MATERIAL AND METHODS
⌅Dataset and study area delimitation
⌅The biogeographical regionalization of the study area was defined within Geographical Information Systems (GIS) framework using ArcMap 10.1 software (ESRI 2012ESRI (Environmental Systems Resource Institute) 2012. ArcGIS Desktop Sofware, Release 10. Redlands, CA, USA.), where a vector file of the biogeographical regionalization of the study area was created by converting the already published map by Good (1974)Good R. 1974. The geography of flowering plants ed. 4. Longman, London. into a polygon vector shapefile to enhance the quality of future analyses. The process was performed in 3 steps: 1) the original map of Good (1974)Good R. 1974. The geography of flowering plants ed. 4. Longman, London. was scanned and converted into TIFF format, then it was georeferenced using a previously georeferenced shapefile; 2) polygons defining the boundaries and the geographic locations of the sub-regions across the study area were created; and 3) attributes and information related to each of the defined provinces were added and linked to the shapefile (Fig. 1).
Delimitation of the Mediterranean region in this study was mainly assessed according to the system of Good (1974)Good R. 1974. The geography of flowering plants ed. 4. Longman, London.. It is necessary to keep in mind that regions are separated from each other not by lines, but by belts inhabited by taxa belonging to the contiguous regions. According to Vargas (2020)Vargas P. 2020. The Mediterranean floristic region: high diversity of plants and vegetation types. In Goldstein M.I. & DellaSala D.A. (eds.), Encyclopedia of the World’s Biomes vol. 3: 602-616. Elsevier, Ashland., there is principally a consensus for recognizing five vegetation belts in the Mediterranean region: (1) thermo-Mediterranean vegetation belt (coastal scrub: maquis/garrigue/phrygana) and conifer-oak woodlands on inland hills; (2) meso-Mediterranean (sclerophyll woodland on plains and piedmont); (3) supra-Mediterranean (oak and pine woodlands up to the altitudinal timberline); (4) oro-Mediterranean (high-altitude bush communities); and (5) cryoro-Mediterranean (alpine communities of herbs). In fact, only the thermo-Mediterranean vegetation belt is present in Egypt.
The chorionomic boundary of the Mediterranean region coincides with the boundary of the typical Mediterranean forests of Quercus ilex L. and the primary area of Olea europaea L. subsp. europaea cultivation. The Mediterranean region can be subdivided into: North-western sub-region, North African sub-region, Eastern sub-region (levant) and Balkans sub-region (Fig. 1).
Regarding Egypt, the Mediterranean territory extends for about 970 km from Sallum, on the Egyptian-Libyan border, to Rafah, on the Egyptian-Palestinian border, with an average width 15-20 km in north-south direction and a limited area of ca. 16,500 km2. The Mediterranean phytogeographical region was divided into three main sub-sectors: 1) western a.k.a. the Mareotis, with mean annual rainfall between 220-150 mm and stretching for 550 km between Sallum and Alexandria; 2) middle a.k.a. Deltaic, stretching for 180 km between Alexandria and Port Said, with width of about 12 km; and 3) east a.k.a. Sinaitic, with an annual rainfall between 150-100 mm and extending for 220 km between Port Said and Rafah (Zahran & al. 1985Zahran M.A., El-Demerdash M.A. & Mashaly I.A. 1985. On the ecology of the deltaic coast of the Mediterranean Sea, Egypt. General survey. Proceeding of fourth Egyptian Botanical Society 4: 1392-1407.; Zahran & Willis 2008Zahran M.A. & Willis A.J. 2008. The vegetation of Egypt vol. 2. Springer Science & Business Media.).
List justification
⌅A preliminary list of Mediterranean endemics in Egypt was prepared based on Täckholm (1974)Täckholm V. 1974. Students’ flora of Egypt ed. 2. Cairo University Press, Cairo. , Greuter & al. (1984-1989)Greuter W., Burdet H.M. & Long G. (eds.). 1984-1989. Med-Checklist. A critical inventory of vascular plants of the circum-Mediterranean countries. 1, 3, 4. OPTIMA, Geneva and Berlin., Boulos (1999- 2005)Boulos L. 1999-2005. Flora of Egypt vols. 1-4. Al-Hadara Publishing, Cairo., Greuter & von Raab-Straube (2008)Greuter W. & von Raab-Straube E. 2008. Med-checklist: a critical inventory of vascular plants of the circum-mediterranean countries. 2. Dicotyledones (Compositae). OPTIMA, Geneva and Berlin., Ahmed (2009)Ahmed D. 2009. Current situation of the flora and vegetation of the Western Mediterranean Desert of Egypt. Ph.D.dissertation. Tanta University, Tanta., Shaltout & al. (2010)Shaltout K., Sharaf El-Din A. & Ahmed D. 2010. Plant life in the Nile Delta: 232. Tanta University Press, Tanta., and El-Khalafy (2018)El-Khalafy M.M. 2018. Red list of the endemic and near endemic plant species in Egypt. M.Sc. Thesis, Botany Department, Faculty of Science, Tanta University, Tanta..
Authentication of the taxa was assessed depending on floras of countries of Mediterranean basin such as Quézel & Santa (1962-1963)Quézel P. & Santa S. 1962-1963. Nouvelle Flore de l’Algérie et des régions désertiques méridionales. Centre National de la Recherche Scientifique, Paris., Tutin & al. (1964-1980)Tutin T.G., Heywood V.H., Burges N.A., Valentine D.H., Walters S.M. & Webb D.M. (eds.). 1964-1980. Flora Europaea. Vols. 1-5. Cambridge University Press, Cambridge. , Davis (1965-1985)Davis P.H. (ed.) 1965-1985. Flora of Turkey and the East Aegean Islands. Vols. 1-9. Edinburgh University Press, Edinburgh., Zohary (1966Zohary M. 1966. Flora Palaestina part I. The Israel Academy of Science and Humanities, Jerusalem Academic Press, Jerusalem., 1987Zohary M. 1987. Flora Palaestina part II. The Israel Academy of Science and Humanities, Jerusalem Academic Press, Jerusalem.), Mouterde (1966-1984)Mouterde P. 1966-1984. Nouvelle flore du Liban et de la Syrie. Vols. 1-4. Dar El-Machreq (imprimerie catholique), Beyrouth , Beck-Mannagetta (1967- 1983)Beck-Mannagetta G. 1967-1983. Flora Bosnae et Hercegovinae. Zemaljski Muzej Bosne i Hercegovine, Sarajevo. 4/2: Posebna Izd. Zem. Muz. Bosne Hercegovine Sarajevu., Franco (1971-1983)Franco J.A. 1971-1983. Nova Flora de Portugal (Continente e Açores). Escolar Editora, Lisboa., Zangheri (1976)Zangheri P. 1976. Flora italica. Cedam, Padova., Haslam & al. (1977)Haslam S.M., Sell P.D. & Wolseley P.A. 1977. A Flora of the Maltese Islands. Malta University Press, Msida., Feinbrun-Dothan (1978Feinbrun-Dothan N. 1978. Flora Palaestina Part 3. The Israel Academy of Science and Humanities, Jerusalem Academic Press, Jerusalem. , 1986Feinbrun-Dothan N. 1986. Flora Palaestina Part 4. The Israel Academy of Science and Humanities, Jerusalem Academic Press, Jerusalem. ), Jafri & El-Gadi (1977-1988)Jafri S. & El-Gadi A. 1977-1988. Flora of Libya. Al-Faateh University, Faculty of Science, Department of Botany and National Academy for Scientific Research (N.A.S.R), Tripoli., Duvigneaud (1979)Duvigneaud J. 1979. Catalogue provisoire de la flore des Baléares ed. 2. Liège. Societé pour l’Échange des Plantes Vasculaires de l’Europe Occidentale et du Bassin Méditerranéen 17( supplément): [1]-43., Pottier-Alapetite (1979-1981)Pottier-Alapetite G. 1979-1981. Flore de la Tunisie. Angiospermes Dicotylédones: 655-1190. Ministère de l’Enseignement Supérieur et de la Recherche Scientifique et Ministère de l’Agriculture, Tunis., Meikle (1977-1985)Meikle R.D. 1977-1985. Flora of Cyprus. Bentham Moxon Trust, Royal Botanic Gardens, Kew., Guinochet & Vilmorin (1973-1984)Guinochet M. & Vilmorin R. de. 1973-1984. Flore de France. Centre National de la Recherche Scientifique, Paris., Smythies (1984-1986)Smythies B.E. 1984-1986. Flora of Spain and the Balearic Islands. Checklist of vascular plants. Englera vol. 3. Botanischer Garten und Botanisches Museum, Berlin-Dahlem. , Castroviejo & al. (1986-2021)Castroviejo S. & al. (eds.). 1986-2021. Flora iberica vols. 1-21. Editorial CSIC, Madrid., Davis & al. (1988)Davis P.H., Tan, K. & Mill, R.R. 1988. Flora of Turkey and the East Aegean Islands (suppl. 1). Vol. 10. Edinburgh University Press, Edinburgh., and Güner & al. (2000)Güner A., Özhatay N., October T. & Başer K.H.C. 2000. Flora of Turkey and the East Aegean Islands (Appendix 2). Vol. 11. Edinburgh University Press, Edinburgh..
The following databases were also consulted to check the recorded plants: Hassler (2004-2022)Hassler M. 2004-2022. World Plants. Synonymic Checklist and Distribution of the World Flora. Version 12.11; last update March 7th, 2022. Website: https://www.worldplants.de [accessed: 21 Mar. 2022]., Flowers in Israel (2005-2022)Flowers in Israel. 2005-2022. Website: http://www.flowersinisrael.com/ [accessed: 3 Mar. 2022]., Euro+Med (2006)Euro+Med. 2006. Euro+Med PlantBase - the information resource for Euro-Mediterranean plant diversity. Website: http://ww2.bgbm.org/EuroPlusMed/ [accessed: 25 Feb. 2022]., Danin & Fragman-Sapir (2016)Danin A. & Fragman-Sapir O. 2016. Flora of Israel Online. Website: https://flora.org.il/en/plants/ [accessed: 3 Jan. 2021]., Med-Checklist (2016)Med-Checklist. 2016. A critical inventory of vascular plants of the circum-mediterranean countries. Website: http://ww2.bgbm.org/mcl/home.asp [accessed: 16 Mar. 2022]., Dimopoulos & al. (2020)Dimopoulos P., Raus T. & Strid A. 2020. Flora of Greece web. Vascular Plants of Greece, an Annotated Checklist. Website: http://portal.cybertaxonomy.org/flora-greece/ [accessed: 25 Feb. 2021]., eflora Maghreb (2021)eflora Maghreb. 2021. Website: https://efloramaghreb.org [accessed: 8 Aug. 2021]. , African Plant Database (2022)African Plant Database 2022. Version 3.4.0, Conservatoire et Jardin Botaniques de la Ville de Genève and South African National Biodiversity Institute, Pretoria. Website: http://africanplantdatabase.ch [retrieved: 14 Mar. 2022]., Chikhali (2022)Chikhali M. 2022. Flora Syria On Line. Website: http://www.florasyria.com [accessed: 26 Mar. 2022]., EPPO (2022)EPPO 2022. European and Mediterranean Plant Protection Organization. Available online; https://gd.eppo.int/ [accessed: 28 Mar. 2022]., Flora of Cyprus (2022)Flora of Cyprus. 2022. A Dynamic Checklist. Website: http://www.flora-of-cyprus.eu [accessed: 20 Apr. 2022]., Flora of Libya (2022)Flora of Libya. 2022. Website: https://floraoflibya.services.ly/display.php?selected=Home [accessed: 20 Apr. 2022]., Flora of Turkey (2022)Flora of Turkey. 2022. Website: https://www.bizimbitkiler.org.tr/v2/liste.php [accessed: 20 Apr. 2022]., GBIF (2022)GBIF 2022. The Global Biodiversity Information Facility. Website: https://www.gbif.org [accessed: 1 Feb. 2022]., JSTOR (2022)JSTOR. 2022. Global Plants on JSTOR, ITHAKA. Website: https://plants.jstor.org/ [accessed: 1 Feb. 2022]., POWO (2022)POWO 2022. Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew. Website: http://www.plantsoftheworldonline.org/ [accessed: 14 Mar. 2022]., VicFlora (2022)VicFlora 2022. Flora of Victoria. Royal Botanic Gardens Victoria. Website: https://vicflora.rbg.vic.gov.au [accessed: 7 Jan. 2022]., and WCSP (2022)WCSP 2022. World Checklist of Selected Plant Families. Facilitated by the Royal Botanic Gardens, Kew. Website: http://wcsp.science.kew.org/ [accessed: 16 Mar. 2022].. Data were also collected from field visits and collection research including the following herbaria: Real Jardín Botánico, Madrid (MA), Tanta University (TANE), Alexandria University (ALEX), Cairo University (CAI), Assiut University (ASTU), Agricultural Research Center (CAIM), Desert Research Center (CAIH), National Research Centre (CAIRC), and National Registry for Egyptian Herbaria (2022)National Registry for Egyptian Herbaria. 2022. Scientific Network of the Academy of Scientific Research and Technology, Egypt. Website: http://networks.asrt.sci.eg/Herbarias/Index [accessed: 14 Mar. 2022].. Information was also compiled from available literature (papers, books, M.Sc. and Ph.D. theses, and scientific reports).
The recorded taxa were arranged alphabetically according to Angiosperm Phylogeny Group system (APG IV: Byng & al. 2016Byng J., Chase M., Christenhusz M., Fay M., Judd W., Mabberley D., Sennikiv A., Soltis D., Soltis P. & Stevens P. 2016. An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG IV. Botanical Journal of Linnean Society 181: 1-20.). The accepted names followed International Plant Names Index (IPNI 2022IPNI 2022. International Plant Names Index. The Royal Botanic Gardens, Kew, Harvard University Herbaria & Libraries and Australian National Botanic Gardens. Website: http://www.ipni.org [accessed: 15 Mar. 2022].), World Flora Online (WFO 2022WFO 2022. World Flora Online. Website: http://www.worldfloraonline.org [accessed: 21 Apr. 2022].), World Checklist of Selected Plant Families (WCSP 2022WCSP 2022. World Checklist of Selected Plant Families. Facilitated by the Royal Botanic Gardens, Kew. Website: http://wcsp.science.kew.org/ [accessed: 16 Mar. 2022].), and Plants of the World Online (POWO 2022POWO 2022. Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew. Website: http://www.plantsoftheworldonline.org/ [accessed: 14 Mar. 2022].).
Species traits
⌅General characteristics of the recorded plants such as habitats, geographical distribution, growth and life forms, sex forms, flowering period and dispersal types were determined from the following publications: Täckholm & Drar (1950-1969)Täckholm V. & Drar M. 1950-1969. Flora of Egypt vols. 2-4. Bulletin of Faculty of Science, Fuoad I University. Cairo., Zohary (1966Zohary M. 1966. Flora Palaestina part I. The Israel Academy of Science and Humanities, Jerusalem Academic Press, Jerusalem., 1987Zohary M. 1987. Flora Palaestina part II. The Israel Academy of Science and Humanities, Jerusalem Academic Press, Jerusalem.), Täckholm (1974)Täckholm V. 1974. Students’ flora of Egypt ed. 2. Cairo University Press, Cairo. , Jafri & El-Gadi (1977-1988)Jafri S. & El-Gadi A. 1977-1988. Flora of Libya. Al-Faateh University, Faculty of Science, Department of Botany and National Academy for Scientific Research (N.A.S.R), Tripoli., Feinbrun-Dothan (1978Feinbrun-Dothan N. 1978. Flora Palaestina Part 3. The Israel Academy of Science and Humanities, Jerusalem Academic Press, Jerusalem. , 1986Feinbrun-Dothan N. 1986. Flora Palaestina Part 4. The Israel Academy of Science and Humanities, Jerusalem Academic Press, Jerusalem. ), Boulos (1999-2005Boulos L. 1999-2005. Flora of Egypt vols. 1-4. Al-Hadara Publishing, Cairo., 2009Boulos L. 2009. Flora of Egypt Checklist, Revised Annotated Edition. Al-Hadara Publishing, Cairo. ), El-Hadidi & Hosni (2000)El-Hadidi M. & Hosni H. 2000. Conservation and threats. In El-Hadidi M.N. (ed.), Flora Aegyptiaca 1: 105-180. Palm Press, Cairo. , Seif El-Nasr & Bidak (2006aSeif El-Nasr M. & Bidak L. 2006a. Conservation and sustainable use of Medicinal plants project, National survey, Northwestern coastal region. Vol I. Medicinal plants in the Area. Final report, March 2006. Mubarak City for Scientific Research and Technology Applications, Mubarak., 2006bSeif El-Nasr M. & Bidak L. 2006b. Conservation and sustainable use of Medicinal plants project, National survey, Northwestern coastal region. Vol II. Medicinal plants in the Area. Final report. Mubarak City for Scientific Research and Technology Applications, Mubarak.), Ahmed (2009)Ahmed D. 2009. Current situation of the flora and vegetation of the Western Mediterranean Desert of Egypt. Ph.D.dissertation. Tanta University, Tanta., Shaltout & al. (2010)Shaltout K., Sharaf El-Din A. & Ahmed D. 2010. Plant life in the Nile Delta: 232. Tanta University Press, Tanta., El-Khalafy (2018)El-Khalafy M.M. 2018. Red list of the endemic and near endemic plant species in Egypt. M.Sc. Thesis, Botany Department, Faculty of Science, Tanta University, Tanta., Bedair (2020)Bedair H. 2020. Composition and pattern of wild trees and shrubs in the Egyptian flora. M. Sc. Thesis. Botany Department, Faculty of Science, Tanta University, Tanta, Egypt)., Mushtaq & al. (2020)Mushtaq W., Bedair H., & Shakeel A. (2020) Halophytes: a phytoremediation tool for salt-affected soils with special reference to indian subcontinent. Handbook of halophytes: from molecules to ecosystems towards biosaline agriculture 1-16., Bedair & al. (2020)Bedair H., Shaltout K., Ahmed D., Sharaf El-Din A., & El-Fahhar, R. 2020. Characterization of the wild trees and shrubs in the Egyptian Flora. Egyptian Journal of Botany 60(1): 147-168., Ghosh & al. (2021)Ghosh S., Falyouna O., Malloum A., Othmani A., Bornman C., Bedair H., ... & Ahmadi, S. 2021. A general review on the use of advance oxidation and adsorption processes for the removal of furfural from industrial effluents. Microporous and Mesoporous Materials 331: 111638., Bedair & al. (2022 aBedair H., Rady H. A., Hussien A. M., Pandey M., Apollon W., AlKafaas S. S., & Ghosh S. 2022 a. Pesticide Detection in Vegetable Crops Using Enzyme Inhibition Methods: a Comprehensive Review. Food Analytical Methods 15: 1979-2000. & bBedair H., Ghosh S., Abdelsalam I. M., Keerio A. A., & AlKafaas S. S. 2022 b. Potential implementation of trees to remediate contaminated soil in Egypt. Environmental science and pollution research 29: 78132-78151.), Ghosh & al. (2022)Ghosh S., AlKafaas S.S., Bornman C., Apollon W., Hussien A.M., Badawy A.E., Amer M.H., Kamel M.B., Mekawy E.A. & Bedair H. 2022. The application of rapid test paper technology for pesticide detection in horticulture crops: a comprehensive review. Beni-Suef University Journal of Basic and Applied Sciences 11: 1-28., Abdelsalam & al. (2022)Abdelsalam I.M., Ghosh S., AlKafaas S.S. & al. 2022. Nanotechnology as a tool for abiotic stress mitigation in horticultural crops. Biologia. https://doi.org/10.1007/s11756-022-01251-z and Shaltout & Bedair (2022)Shaltout K. & Bedair H. 2022. Diversity, distribution and regional conservation status of the Egyptian tree flora. African Journal of Ecology 00: 1-29.. The dispersal type of the collected diaspores of many of the recorded taxa was assessed according to Dansereau & Lems (1957)Dansereau P. & Lems K. 1957. The Grading of Dispersal Types in Plant Communities and their Ecological Significance. Institut Botanique de l’Université de Montréal, Montréal 71: 1-52. (Table 1). The main assigned sex forms were bisexual (i.e. hermaphrodite) having both male and female sex organs in the flower, or unisexual, either monoecious (each plant has both male and female flowers) or dioecious (the male and female blossoms appear on separate plants), and polygamous.
| Dispersal type | Description |
|---|---|
| Autochore | Diaspora without obvious adaptations to any external agent. |
| Barochore | Diaspora characterized mainly by their weight and the lack of any other feature. |
| Pyrenochore | Diaspora lacks distinctive adaptations, too heavy to be carried by breeze (0.5-0.999 mg). |
| Microsclerochore | Diaspora lack distinctive adaptations, too heavy to be carried by breeze (0.005-0.449 mg). |
| Ballochore | Diaspora forcibly ejected from parent plant. |
| Auxochore | No disarticulating from parent plant before diaspora is deposited at a site of further development. |
| Heterochore | Diaspora either with appendages or extremely light or provided with fleshy outer layers. |
| Cyclochore | Diaspora largely consisting of accessory parts, forming a voluminous spherical frame. |
| Pterochore | Diaspora with scarious wing like or plumose appendages. |
| Pogonochore | Diaspora with long, hair like or plumose appendages. |
| Desmochore | Diaspora with short, stiff, spring, glandular or hooked appendages adhering to rough surface. |
| Sporochore | Diaspore very minute, can be carried by breeze (0.001-0.004 mg). |
| Sarcochore | Diaspore with soft and fleshy outer layers. |
Life forms follow the system of Raunkiaer (1937)Raunkiaer C. 1937. Plant Life Forms. Clarendon, Oxford.. This system which is designed for the northern temperate zone and based on the location of renewal buds was coded and identified as follows:
-
Phanerophytes: plants with permanent buds borne at height > 25 cm. They are subdivided into: mega-phanerophyte (over 30 m); meso-phanerophyte (8-30 m); micro-phanerophyte (2-8 m); and nano-phanerophyte (under 2 m).
-
Epiphytes: these plants cling to other plants for support; they are not attached to the soil.
-
Stem succulents: plants with succulent stems and without proper foliage leaves.
-
Chamaephytes: plants with permanent buds borne above the soil surface till a height < 25 cm. This group is subdivided into active chamaephytes (with shoots diageotropic and persistent throughout their whole length); passive chamaephytes (with weak stems which lie on the ground); suffruticose chamaephytes (the perennating parts remain on the surface of the ground after the herbaceous parts have died away oil the approach of the critical season); and cushion plants (a reduced form of active chamaephytes).
-
Hemicryptophytes: plants with permanent buds borne close to soil surface. This category is further divided into protohemicryptophytes (with only stem leaves); partial rosette plants (with both stem and basal rosette leaves); and rosette plants (with only basal rosette leaves).
-
Cryptophytes: with permanent buds borne under soil surface in case of geophytes, in the mud overlain by water in case of helophytes or in the water in case of hydrophytes.
-
Therophytes: plants complete their life-cycle within a single favourable season.
-
Parasites: these plants live on or in the host which provides them with nutriment.
Phytogeographical sectors in this study were assigned according to Zahran & al. (1985)Zahran M.A., El-Demerdash M.A. & Mashaly I.A. 1985. On the ecology of the deltaic coast of the Mediterranean Sea, Egypt. General survey. Proceeding of fourth Egyptian Botanical Society 4: 1392-1407.. Besides, the global distribution of the recorded taxa (i.e. floristic regions) was assigned following the system of Good (1974)Good R. 1974. The geography of flowering plants ed. 4. Longman, London., which divided the globe into six kingdoms, three subkingdoms and thirty nine floristic regions. Distribution of the recorded taxa in countries of Mediterranean was also checked in some databases such as Hassler (2004-2022)Hassler M. 2004-2022. World Plants. Synonymic Checklist and Distribution of the World Flora. Version 12.11; last update March 7th, 2022. Website: https://www.worldplants.de [accessed: 21 Mar. 2022]., Euro+Med (2006)Euro+Med. 2006. Euro+Med PlantBase - the information resource for Euro-Mediterranean plant diversity. Website: http://ww2.bgbm.org/EuroPlusMed/ [accessed: 25 Feb. 2022]., Med-Checklist (2016)Med-Checklist. 2016. A critical inventory of vascular plants of the circum-mediterranean countries. Website: http://ww2.bgbm.org/mcl/home.asp [accessed: 16 Mar. 2022]., Flora of Libya (2022)Flora of Libya. 2022. Website: https://floraoflibya.services.ly/display.php?selected=Home [accessed: 20 Apr. 2022]., POWO (2022)POWO 2022. Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew. Website: http://www.plantsoftheworldonline.org/ [accessed: 14 Mar. 2022]., WCSP (2022)WCSP 2022. World Checklist of Selected Plant Families. Facilitated by the Royal Botanic Gardens, Kew. Website: http://wcsp.science.kew.org/ [accessed: 16 Mar. 2022]., GBIF (2022)GBIF 2022. The Global Biodiversity Information Facility. Website: https://www.gbif.org [accessed: 1 Feb. 2022]., and JSTOR (2022)JSTOR. 2022. Global Plants on JSTOR, ITHAKA. Website: https://plants.jstor.org/ [accessed: 1 Feb. 2022]..
Rarity forms of the recorded taxa were assessed depending on the national geographical range, habitat specificity and local abundance according to Rabinowitz (1981)Rabinowitz D. 1981. Seven forms of rarity. In Synge H. (ed.), The Biological Aspects of Rare Plant Conservation: 205-217. John Wiley and Sons Ltd, London.. The eight rarity forms are coded and explained in Table 2.
| Local population size | Geographical range, habitat specificity | |||
|---|---|---|---|---|
| Wide | Narrow | Wide | Narrow | |
| Large (L), abundant somewhere (A) | Locally abundant over a large range in several habitats (LWA) | Locally abundant over a large range in a specific habitat (LNA) | Locally abundant in several habitats but restricted geographically (SWA) | Locally abundant in a specific habitat but restricted geographically (SNA) |
| Small (S), non abundant (Na) | Constantly sparse over a large range and in several habitats (LWNa) | Constantly sparse over a large range in a specific habitat (LNNa) | Constantly sparse and geographically restricted in several habitats (SWNa) | Constantly sparse and geographically restricted in a specific habitat (SNNa) |
RESULTS
⌅List justification
⌅A preliminary list of 275 Mediterranean endemic taxa in Egypt was prepared. Boulos (1999-2005)Boulos L. 1999-2005. Flora of Egypt vols. 1-4. Al-Hadara Publishing, Cairo. recorded 275 Mediterranean endemic taxa in the Egyptian flora. Of these, 106 (38.5%) Mediterranean endemics were recorded in the western Mediterranean region of Egypt by Ahmed (2009)Ahmed D. 2009. Current situation of the flora and vegetation of the Western Mediterranean Desert of Egypt. Ph.D.dissertation. Tanta University, Tanta.. Indeed, the present study has reduced this number to be 57 (20.7%) Mediterranean endemic taxa in Egypt (Appendices 1 and 2). Taxonomic authorities are ommitted from the names of taxa mentioned in the text below; they are included in the taxon lists of Appendices 1 and 2.
Taxonomic diversity
⌅There were 57 Mediterranean endemic taxa, including species, subspecies and varieties, recorded in this study belonging to 46 genera and 22 families. The most represented genera were Allium and Fumaria (4 taxa each); Bellevalia (3 taxa); Muscari, Centaurea and Limonium (2 taxa each). Gymnosperms were not represented by any taxon, while angiosperms were represented by 2 clades (Table 3).
| Clade | Families (F) | Genera (G) | Species (S) | Subspecies (Sub) | Varieties (V) | Sub/S | S/G | G/F |
|---|---|---|---|---|---|---|---|---|
| Monocots | 4 | 10 | 17 | 0 | 0 | 0 | 1.7 | 2.5 |
| Eudicots | 18 | 36 | 40 | 5 | 2 | 0.1 | 1.1 | 2 |
| Total | 22 | 46 | 57 | 5 | 2 | 0.1 | 2.8 | 4.5 |
Four monocot families were recorded (Amaryllidaceae, Asparagaceae, Poaceae and Posidoniaceae), with 10 genera and 17 species, while eudicots were the most represented with 18 families. The highly represented families were Asteraceae (10 taxa), Fabaceae and Asparagaceae (8 taxa each), and Amaryllidaceae (5 taxa) (Fig. 2). On the other hand, 12 families were represented by only 1 taxon (Posidoniaceae, Convolvulaceae, Euphorbiaceae, Resedaceae, Apiaceae, Caprifoliaceae, Caryophyllaceae, Rubiaceae, Santalaceae, Solanaceae and Scrophulariaceae) (Appendix 1). The diversity of the major taxonomic groups indicated that the eudicots were the most diverse in terms of families, genera, species, subspecies and varieties, whereas monocots were the least. The ratio of genus to family (G/F) had a maximum value in monocots (2.5) and a minimum in eudicots (2). The ratio of species to genus (S/G) had a maximum in monocots (1.7) and a minimum in eudicots (1.1), while the subspecies to species ratio was very low in all the major taxonomic groups (Table 3).
Habitats
⌅Fourteen major habitats harbour the Mediterranean endemics in Egypt: 10 were natural habitats and 4 were anthropogenic habitats. The most represented habitats were the coastal dunes (17 taxa = 29.8%), followed by non-saline depressions (16 taxa = 28.1%), whereas alluvial soils (only one taxon: Bellevalia warburgii) and waste lands (2 taxa = 3.5%) were the least represented habitats (Fig. 3).
Geographical distribution
⌅National geographic distribution.-The Mareotis (west) subsector was the richest of the three subsectors with 46 taxa (= 80.7%; e.g. Allium mareoticum, Muscari albiflorum and Scilla peruviana), followed by the Sinaitic (east) subsector with 15 taxa (26.3%; e.g., Bellevalia warburgii, Coronilla repanda, and Vicia sinaica), whereas, the Deltaic (middle) subsector had the least Mediterranean endemics with only five taxa (8.8%).
Global geographical distribution.-All the recorded taxa belonged to the Mediterranean region in the Boreal kingdom, which is divided into four sub-regions: North African sub-region (52 taxa = 91.2%), Eastern (levant) sub-region (36 taxa = 63.2%), Balkans sub-region (21 taxa = 36.8%) and North-western sub-region (16 taxa = 28.1%). The Mediterranean endemics in Egypt were recorded in 21 Mediterranean basin countries out of 25 (Table 4). The greatest number of taxa was recorded in Libya (29 taxa = 50.9%), followed by Palestine (24 taxa = 42.1%), then Syria and Lebanon (22 taxa each = 38.6%), while the lowest number (one taxon = 1.8%) was reported in San Marino, Slovenia and Bosnia and Herzegovina. On the other hand, no taxa were recorded in Malta, Monaco, and Holy See (Vatican City) (Fig. 4). Interestingly, 47 Mediterranean endemics (82.5%) were recorded in Egypt (excluding Sinai Peninsula that belongs to North African sub-region), and 15 (26.3%) in Sinai Peninsula belonging to Eastern sub-region.
| Taxon | North African | Eastern sub-region (levant) | Balkans sub-region | North-western sub-region | Total | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| E | L | T | A | M | P | S | L | C | T | S | G | A | H | M | B | S | I | F | S | P | S | ||
| G | Y | S | G | O | L | Y | E | Y | U | I | R | L | R | J | K | L | T | R | P | O | M | ||
| Allium barthianum Asch. & Schweinf. | + | + | 2 | ||||||||||||||||||||
| Allium blomfieldianum Asch. & Schweinf. | + | + | 2 | ||||||||||||||||||||
| Allium mareoticum Bornm. & Gauba | + | 1 | |||||||||||||||||||||
| Allium trifoliatum Cirillo | + | + | + | + | + | + | + | + | + | 9 | |||||||||||||
| Anchusa undulata subsp. hybrida (Ten.) Cout. | + | + | + | + | + | + | + | + | + | + | + | + | + | 13 | |||||||||
| Anthemis microsperma Boiss. & Kotschy | + | 1 | |||||||||||||||||||||
| Apium crassipes (W.D.J. Koch ex Rchb.) Rchb.f. | + | + | + | + | 4 | ||||||||||||||||||
| Bellevalia salah-eidii Täckh. & Boulos | + | 1 | |||||||||||||||||||||
| Bellevalia sessiliflora (Viv.) Kunth | + | + | + | 3 | |||||||||||||||||||
| Bellevalia warburgii Feinbrun | + | + | + | + | 4 | ||||||||||||||||||
| Centaurea aegialophila Wagenitz | + | + | + | + | + | 5 | |||||||||||||||||
| Centaurea pumilio L. | + | + | + | + | 4 | ||||||||||||||||||
| Convolvulus humilis Jacq. | + | + | + | + | + | + | + | + | + | + | + | + | 12 | ||||||||||
| Coronilla repanda (Poir.) Guss. | + | + | + | + | + | + | + | + | + | + | 10 | ||||||||||||
| Crepis aculeata Boiss. | + | + | + | + | 4 | ||||||||||||||||||
| Cynara cornigera Lindl. | + | + | + | + | 4 | ||||||||||||||||||
| Cynosurus coloratus Lehm. ex Steud. | + | + | + | + | + | + | + | + | 8 | ||||||||||||||
| Desmazeria philistaea (Boiss.) H.Scholz | + | + | + | + | + | + | 6 | ||||||||||||||||
| Ebenus armitagei Schweinf. & Taub. | + | + | 2 | ||||||||||||||||||||
| Echinops taeckholmianus Amin | + | 1 | |||||||||||||||||||||
| Euphorbia parvula Delile | + | + | 2 | ||||||||||||||||||||
| Filago mareotica Delile | + | + | + | + | + | + | 6 | ||||||||||||||||
| Fumaria gaillardotii Boiss. | + | + | + | + | + | + | + | + | + | + | + | + | + | + | + | 15 | |||||||
| Fumaria judaica Boiss. subsp. judaica | + | + | + | + | + | + | + | + | + | + | 10 | ||||||||||||
| Fumaria microstachys Kralik ex Hausskn. | + | 1 | |||||||||||||||||||||
| Sulla spinosissima (L.) B.H.Choi & H.Ohashi | + | + | + | + | + | + | + | + | + | + | + | + | + | + | + | 15 | |||||||
| Helianthemum crassifolium subsp. sphaerocalyx (Gauba & Janch.) Maire | + | + | 2 | ||||||||||||||||||||
| Helichrysum orientale (L.) Gaertn. | + | + | + | 3 | |||||||||||||||||||
| Heliotropium hirsutissimum Grauer | + | + | + | + | + | + | + | + | 8 | ||||||||||||||
| Herniaria cyrenaica F.Herm. | + | + | 2 | ||||||||||||||||||||
| Hyoseris radiata subsp. graeca Halácsy | + | + | + | + | 4 | ||||||||||||||||||
| Lathyrus marmoratus Boiss. & Blanche | + | + | + | + | + | + | 6 | ||||||||||||||||
| Leopoldia bicolor (Boiss.) Eig & Feinbrun | + | + | + | + | + | 5 | |||||||||||||||||
| Limonium echioides (L.) Mill. | + | + | + | + | + | + | + | + | + | + | + | + | 12 | ||||||||||
| Limonium sinuatum subsp. romanum Täckh. & Boulos | + | 1 | |||||||||||||||||||||
| Linaria joppensis Bornm. | + | + | 2 | ||||||||||||||||||||
| Lotus cytisoides L. | + | + | + | + | + | + | + | + | + | + | + | + | + | + | + | + | 16 | ||||||
| Lycium schweinfurthii var. aschersonii (Dammer) Feinbrun | + | + | 2 | ||||||||||||||||||||
| Muscari albiflorum (Täckh. & Boulos) Hosni | + | 1 | |||||||||||||||||||||
| Muscari parviflorum Desf. | + | + | + | + | + | + | + | + | + | + | + | + | + | + | 14 | ||||||||
| Muscari salah-eidii (Täckh. & Boulos) Hosni | + | ||||||||||||||||||||||
| Pancratium arabicum Sickenb. | + | 1 | |||||||||||||||||||||
| Posidonia oceanica (L.) Delile | + | + | + | + | + | + | + | + | + | + | + | + | + | + | + | + | 16 | ||||||
| Reseda orientalis (Müll.Arg.) Boiss. | + | + | + | + | + | + | + | 7 | |||||||||||||||
| Scilla peruviana L. | + | + | + | + | + | + | + | + | 8 | ||||||||||||||
| Taraxacum minimum (Brig. ex Guss.) N.Terracc. | + | + | + | + | + | + | + | + | + | + | 10 | ||||||||||||
| Teucrium brevifolium Schreb. | + | + | + | + | + | 5 | |||||||||||||||||
| Thesium humile var. maritima (N.D.Simpson) F.M.Saad | + | 1 | |||||||||||||||||||||
| Thymbra capitata (L.) Cav. | + | + | + | + | + | + | + | + | + | + | + | + | + | + | + | + | + | 17 | |||||
| Trifolium argutum Sol. | + | + | + | + | + | + | + | 7 | |||||||||||||||
| Trigonella berythea Boiss. & Blanche | + | + | + | + | + | + | 6 | ||||||||||||||||
| Trisetaria koelerioides (Bornm. & Hack.) Melderis | + | + | + | + | 4 | ||||||||||||||||||
| Valantia columella (Ehrenb. ex Boiss.) Bald. | + | + | 2 | ||||||||||||||||||||
| Valerianella petrovitchii Asch. | + | + | 2 | ||||||||||||||||||||
| Verbascum letourneuxii Asch. | + | + | 2 | ||||||||||||||||||||
| Veronica syriaca Roem. & Schult. | + | + | + | + | + | 5 | |||||||||||||||||
| Vicia sinaica Boulos | + | 1 | |||||||||||||||||||||
| Total | 47 | 29 | 15 | 14 | 9 | 24 | 22 | 22 | 21 | 18 | 15 | 21 | 6 | 6 | 4 | 1 | 1 | 15 | 7 | 10 | 6 | 1 | |
Furthermore, there were 11 steno-endemics recorded only in Egypt (19.3% of the total Mediterranean endemics). They were Allium mareoticum, Anthemis microsperma, Bellevalia salah-eidii, Echinops taeckholmianus, Fumaria microstachys, Limonium sinuatum subsp. romanum, Muscari albiflorum, Pancratium arabicum, Thesium humile var. maritima, Muscari salah-eidii and Vicia sinaica. In addition, nine near-endemic taxa were recorded in Egypt and Libya (Allium barthianum, Allium blomfieldianum, Ebenus armitagei, Euphorbia parvula, Helianthemum crassifolium subsp. sphaerocalyx, Herniaria cyrenaica, Valantia columella, Valerianella petrovitchii and Verbascum letourneuxii), while two taxa (Lycium schweinfurthii var. aschersonii and Linaria joppensis) were recorded in Egypt and Palestine. Besides, Thymbra capitata, Posidonia oceanica and Lotus cytisoides were widely distributed in the Mediterranean basin. Regarding the life span, the perennials dominated the annuals.
Growth, life and sex forms
⌅Regarding the growth forms of the recorded taxa, the highest percentage of them were perennials (31 taxa = 54.4% of the total taxa), while annuals were represented by 26 taxa (45.6%). The life form determination indicated that therophytes (26 taxa = 45.6%) constituted the highest percentage of Mediterranean endemics, followed by geophyte-helophytes (13 taxa = 22.8%), hemicryptophytes (nine taxa = 15.8), and chamaephytes (five taxa = 8.8%). Posidonia oceanica was the only represented hydrophyte, while phanerophytes were represented by Ebenus armitagei, Helichrysum orientale and Lycium schweinfurthii var. aschersonii (Fig. 5). The sex form of Mediterranean endemics was arranged ascendingly as follows: monoecious (three taxa = 5.3%) and hermaphrodite (54 taxa = 94.7%).
Flowering period
⌅Analysis of the flowering time indicated a gradual increase in the frequency of the flowered taxa from December (two taxa = 3.5%) till reaching a maximum in April (48 taxa = 84.2%) and March (41 taxa = 71.9%) forming positively skewed curve. Generally, the period from March to May was characterized by the highest flowering peak, while the period from September to December was characterized by the lowest (Fig. 6). In relation to life forms therophytes had maximum values followed by hemicryptophytes and geophyte-helophytes. It’s obvious that all the recorded life forms had maximum values in March and April. Surprisingly, only phanerophytes stay flowered all the year (Fig. 6).
Dispersal types
⌅Determination of dispersal types indicated that the ballochores (21 taxa = 36.8% of the total plant taxa) were the most represented dispersal type, followed by the pogonochores (11 taxa = 19.3%), then the sarcochores (nine taxa = 15.8%) and microsclerochores (six taxa = 10.5%) (Fig. 7). On the other hand, cyclochores, desmochores and sporochores were the least represented dispersal types (only one taxon each = 1.8%).
Rarity forms
⌅The relation between the number of Mediterranean endemics and the rarity forms indicated that SNN was the most represented (60 taxa = 92.3%), followed by SNA (four taxa = 6.2%). On the contrary, SWN was the least represented by only one taxon (Verbascum letourneuxii).
DISCUSSION
⌅List justification
⌅In the present study, 218 taxa were excluded from the preliminary list of Mediterranean Egyptian endemism. For example, Tripodion tetraphyllum was recorded in the Netherlands (JSTOR 2022JSTOR. 2022. Global Plants on JSTOR, ITHAKA. Website: https://plants.jstor.org/ [accessed: 1 Feb. 2022].) and inner Anatolia (Hassler 2004-2022)Hassler M. 2004-2022. World Plants. Synonymic Checklist and Distribution of the World Flora. Version 12.11; last update March 7th, 2022. Website: https://www.worldplants.de [accessed: 21 Mar. 2022].. Although Leiotulus alexandrinus is a Mediterranean element, it was collected along Gulf of Suez, eastern desert, Egypt (Abd El-Ghani & al. 2017Abd El-Ghani M., Salama F., Salem B., El-Hadidy A. & Abdel-Aleem M. 2017. Phytogeography of the Eastern Desert flora of Egypt. Wulfenia 24: 97-120.; Hassler 2004-2022Hassler M. 2004-2022. World Plants. Synonymic Checklist and Distribution of the World Flora. Version 12.11; last update March 7th, 2022. Website: https://www.worldplants.de [accessed: 21 Mar. 2022].). Therefore, it was excluded from Mediterranean endemics list in this study. Although the endemic Brassica deserti was recorded by Kamel & al. (2008)Kamel W., Zaghloul M., El-Wahab A. & Moustafa A.R. 2008. Current status of the flora of North Sinai: Losses and Gains. Catrina: The International Journal of Environmental Sciences 3: 11-26. only in the Mediterranean coast of Sinai, it was indicated by El-Khalafy & al. (2021)El-Khalafy M.M., Ahmed D., Shaltout K.H., Al-Sodany Y.M. & Haroun S.A. 2021. Re-assessment of the endemic taxa in the Egyptian Flora. African Journal of Ecology 59: 784-796. in Gebel Igma, southern Sinai. Hence, it was excluded from the present study. The same status is noticed for Convolvulus palaestinus that was collected from southern Sinai by El-Husseini & al. (2008)El-Husseini N., Abd El-Ghani M.M. & El-Naggar S.I. 2008. Biogeography and diversity of the tubiflorae in Egypt. Polish Botanical Journal 53: 105-124..
Notably, some Mediterranean elements were excluded for their extension to adjacent regions. For example, Aegilops longissima, Astragalus trimestris, Ononis natrix subsp. stenophylla and Trigonella maritima extend into adjacent territories of the Saharo-Arabian region as mentioned by Feinbrun-Dothan (1978Feinbrun-Dothan N. 1978. Flora Palaestina Part 3. The Israel Academy of Science and Humanities, Jerusalem Academic Press, Jerusalem. , 1986Feinbrun-Dothan N. 1986. Flora Palaestina Part 4. The Israel Academy of Science and Humanities, Jerusalem Academic Press, Jerusalem. ) and Zohary (1966Zohary M. 1966. Flora Palaestina part I. The Israel Academy of Science and Humanities, Jerusalem Academic Press, Jerusalem., 1987Zohary M. 1987. Flora Palaestina part II. The Israel Academy of Science and Humanities, Jerusalem Academic Press, Jerusalem.). Even though Trisetaria koelerioides was recorded in Suadi Arabia in POWO (2022)POWO 2022. Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew. Website: http://www.plantsoftheworldonline.org/ [accessed: 14 Mar. 2022]. and Hassler (2004-2022)Hassler M. 2004-2022. World Plants. Synonymic Checklist and Distribution of the World Flora. Version 12.11; last update March 7th, 2022. Website: https://www.worldplants.de [accessed: 21 Mar. 2022]., it is recorded as Mediterranean endemic in the present study. It does not exist in Chaudhary (1999-2001)Chaudhary S. 1999-2001. Flora of the Kingdom of Saudi Arabia vols. 1-3. Koeltz Botanical Books.. In addition, identification of T. koelerioides in the literature could have been mistaken with Trisetaria chaudharyana H.Scholz (Eflora of the Kingdom of Saudi Arabia 2020E flora of the Kingdom of Saudi Arabia. 2020. Website: https://floraofksa.myspecies.info/ [accessed: 14 Mar. 2022]. ).
Indeed, Heliotropium hirsutissimum was recorded in Suadi Arabia in Hassler (2004-2022)Hassler M. 2004-2022. World Plants. Synonymic Checklist and Distribution of the World Flora. Version 12.11; last update March 7th, 2022. Website: https://www.worldplants.de [accessed: 21 Mar. 2022]., but Chaudhary (1985)Chaudhary S. 1985. Studies on Heliotropium in Saudi Arabia. Arab Gulf Journal of Scientific Research 3: 33-53. elucidated that most reports of this species from Suadi Arabia could possibly be a misidentification of H. arbainense Fresen. Consequently, it can be considered as an east Mediterranean endemic. The endemic Anthemis microsperma was recorded by Täckholm (1974)Täckholm V. 1974. Students’ flora of Egypt ed. 2. Cairo University Press, Cairo. in only the western Mediterranean region, but Boulos (1999 -2005)Boulos L. 1999-2005. Flora of Egypt vols. 1-4. Al-Hadara Publishing, Cairo.recorded it from northern Sinai. There are no authentically identified collected specimens supporting its occurrence in Sinai. It might have been observed there only one time and then disappeared or was misidentified with another similar taxa. The same case holds for Anchusa undulata subsp. hybrida that was recorded in Nile region in Boulos (1999-2005)Boulos L. 1999-2005. Flora of Egypt vols. 1-4. Al-Hadara Publishing, Cairo. in error.
Region delimitation and characterization
⌅As a result of climate change, the Mediterranean region’s borders with the Euro-Siberian region to the north (Europe) and the Saharan region to the south (Africa) have been fluctuating over millions of years (Vargas 2020Vargas P. 2020. The Mediterranean floristic region: high diversity of plants and vegetation types. In Goldstein M.I. & DellaSala D.A. (eds.), Encyclopedia of the World’s Biomes vol. 3: 602-616. Elsevier, Ashland.). However, the northern and southern boundaries of the region are overall relatively decipherable, and disagreement among authors appears only in relation to comparatively small areas (mainly the Iberian and Balkan Peninsulas). In contrast, the establishment of both the western and eastern boundaries particularly is not generally agreed upon (Takhtajan 1986Takhtajan A. 1986. Floristic regions of the world. University of California Press, Berkeley.).
On the national scale, along the years, there have been some problems associated with the delimitation of phytogeographical regions, especially the Mediterranean floristic region in Egypt. Muschler (1912)Muschler R.C. 1912. A manual flora of Egypt vol. 1. R. Friedlaender, Berlin., Täckholm & Drar (1950-1969)Täckholm V. & Drar M. 1950-1969. Flora of Egypt vols. 2-4. Bulletin of Faculty of Science, Fuoad I University. Cairo., Hassib (1951)Hassib M. 1951. Distribution of plant communities in Egypt. Bulletin of Faculty of Science, Fouad University, Cairo. and Täckholm (1956Täckholm V. 1956. Students’ flora of Egypt. Anglo - Egyption Bookshop, Cairo. , 1974Täckholm V. 1974. Students’ flora of Egypt ed. 2. Cairo University Press, Cairo. ) demonstrated that the Mediterranean region in Egypt comprises two subregions: the Western Mediterranean coastal region (which stretches from Sallum to Alexandria, including Rosetta) and the Eastern Mediterranean coastal region (which stretches from Port Said to Rafah). Further, Zohary (1973)Zohary M. 1973. Geobotanical foundations of the Middle East. G. Fischer, Stuttgart. clarified that Mediterranean coast of Egypt harboured vegetation of the “Batha” type as well as the order Ballotelia undulatae belonging to the class Quercetia calliprini of the Eu-Mediterranean vegetation.
Zohary (1973)Zohary M. 1973. Geobotanical foundations of the Middle East. G. Fischer, Stuttgart. and Takhtajan (1986)Takhtajan A. 1986. Floristic regions of the world. University of California Press, Berkeley. proposed that there were two gaps in the Mediterranean territory along the North African sub-region: first gap in northern Egypt from Omayed to Rafah, and the second one in Libya along the Great Syrte between Tripoli and Benghazi. Hence the Saharo-Arabian vegetation advances quite close to the coast. Wickens (1976)Wickens G.E. 1976. The Flora of Jebel Marra (Sudan Republic) and its Geographical Affinities. Royal Botanic Gardens, Kew. restricted the North African gap to be only in Sinai (between Port Said and Rafah).
It is sad to report that Egypt had already lost over one hundred kilometers of its Mediterranean territory due to climate change, human activities, especially tourist summer resorts. As a result, it is now difficult to find any trace of the natural vegetation reported earlier in this region (El-Hadidi & Hosni 2000El-Hadidi M. & Hosni H. 2000. Conservation and threats. In El-Hadidi M.N. (ed.), Flora Aegyptiaca 1: 105-180. Palm Press, Cairo. ; Halmy 2012Halmy M.W.A. 2012. Environmental risk assessment for habitats of the Egyptian northwestern coastal desert. Ph.D.dissertation, University of Idaho, Idaho.; Halmy & al. 2015aHalmy M.W.A., Gessler P.E., Hicke J.A. & Salem B.B. 2015a. Land use/land cover change detection and prediction in the north-western coastal desert of Egypt using Markov-CA. Applied Geography 63: 101-112., 2015bHalmy M.W., Gessler P.E. & Heneidy S.Z. 2015b. Implications of human induced changes on the distribution of important plant species in the northwestern coastal desert of Egypt. Renewable Energy and Sustainable Development 1: 243-263.; Halmy 2019Halmy M.W.A. 2019. Assessing the impact of anthropogenic activities on the ecological quality of arid Mediterranean ecosystems (case study from the northwestern coast of Egypt). Ecological Indicators 101: 992-1003.; Halmy & al. 2019Halmy M.W.A., Fawzy M., Ahmed D.A., Saeed N.M. & Awad M.A. 2019. Monitoring and predicting the potential distribution of alien plant species in arid ecosystem using remotely-sensed data. Remote Sensing Applications: Society and Environment 13: 69-84.). Nevertheless, the current available data provide enough evidence for extending the Mediterranean territory in Egypt from Sallum, on the Egyptian-Libyan border, to Rafah, on the Egyptian-Palestinian border, with 3 subsectors: western (from Sallum to Alexandria), middle (between Alexandria and Port Said) and eastern (between Port Said and Rafah) as elucidated by Zahran & al. (1985)Zahran M.A., El-Demerdash M.A. & Mashaly I.A. 1985. On the ecology of the deltaic coast of the Mediterranean Sea, Egypt. General survey. Proceeding of fourth Egyptian Botanical Society 4: 1392-1407.. The Mareotis (western) subsector of Mediterranean coastal belt in Egypt is by far the richest part in Mediterranean endemics because it receives a higher amount of rainfall (Zahran 2010Zahran M.A. 2010. Afro-Asian Mediterranean coastal lands. In Gilbert, F. ed., Climate-Vegetation: 1-103. Springer, Dordrecht). One other study, to our knowledge, has shown that about 60% of the Mediterranean taxa in Egypt do exist in the Mareotis subsector (El-Hadidi & Hosni 2000El-Hadidi M. & Hosni H. 2000. Conservation and threats. In El-Hadidi M.N. (ed.), Flora Aegyptiaca 1: 105-180. Palm Press, Cairo. ).
The Mediterranean coastal land of Egypt is characterized by outstanding physiographic variations which leads to the differentiation of several types of habitats. The predominance of coastal dunes vegetation found in this study agrees to some extent with Batanouny (1999)Batanouny K.H. 1999. The Mediterranean coastal dunes in Egypt: an endangered landscape. Estuarine, Coastal and Shelf Science 49: 3-9. and Ahmed & al. (2015)Ahmed D., Shaltout K., Hosni H. & El-Fahar R. 2015. Flora and vegetation of the different habitats of the western Mediterranean region of Egypt. Taeckholmia 35: 45-76. who stated that the majority of the Mediterranean coast in Egypt is bordered by sand dunes which represent a landscape with special characteristics and features. In fact, there are different types of dunes: (1) the mobile dunes that are characterized by loose, mobile sand and specialized plant species that are usually sand binders, which can tolerate the burial of their shoot systems in sand and the exposure of their roots. These plants are capable of producing adventitious roots from the buried vegetative part (such as Hyoseris radiata subsp. graeca, Centaurea pumilio and Pancratium arabicum); and (2) the consolidated dunes, characterized by phreatophytes that send deep roots which penetrate into the dunes to make use of the deep-sited fresh water (such as Helianthemum crassifolium subsp. sphaerocalyx and Lotus polyphyllos).
Furthermore, non-saline depressions occupy the major part of the land surface between the coastal ridges parallel to the coast such as the Abu Sir Depression, between the coastal and Abu Sir ridges; and the frontal plain, between the Gebel Mariut ridge and the Mariut tableland (Ayyad 1976 Ayyad M.A. 1976. Vegetation and Environment of the Western Mediterranean Coastal Land of Egypt: IV. The Habitat of Non-Saline Depressions. The Journal of Ecology 64: 713-722. ). They are inhabited by Mediterranean endemics such as Anthemis microsperma, Muscari parviflorum, Verbascum letourneuxii, and Cynara cornigera.
The term ‘life form’ is distinct from the term ‘growth form’. The hereditary transmitted growth form is the morphology of the individual’s stem, whereas the environmentally influenced life form is the overall appearance of the plant community (Glime 2017Glime J. (ed.) 2017. Bryophyte Ecology vol. 1: Physiological Ecology. Michigan Technological University and the International Association of Bryologists, Michigan.). One spectacular phenomenon, to be noticed here, is the prevalence of perennials over annuals in the Mediterranean basin. This finding agrees to some extent with Zohary (1973)Zohary M. 1973. Geobotanical foundations of the Middle East. G. Fischer, Stuttgart. who assumed that predominance of sclerophyllous evergreen perennials is a characteristic trait that distinguishes this subsector from the adjacent ones. Therophytes flower during the rainy season, giving the coastal belt a temporary flush as a grassland desert. Whilst, woody shrubs and perennial herbs dominate during the longer dry periods giving the scrub vegetation of the area, which is scattered sparsely and grouped in patches (Zahran 2010Zahran M.A. 2010. Afro-Asian Mediterranean coastal lands. In Gilbert, F. ed., Climate-Vegetation: 1-103. Springer, Dordrecht). The prevalence of hemicryptophytes can be due to the widespread degradation of ecological conditions as a result of human activity and climate change (Habib & al. 2020Habib N., Regagba Z., Miara M.D., Ait Hammou M. & Snorek J. 2020. Floristic diversity of steppe vegetation in the region of Djelfa, North-West Algeria. Acta Botanica Malacitana 45: 37-46.). Phanerophytes came in the next order, a result that agrees with Kadi-Hanifi (2003)Kadi-Hanifi H. 2003. Diversité biologique et phytogéographique des formations à Stipa tenacissima L. de l‘Algérie. Science et Changements Planétaires/Sécheresse 14: 169-179., who elucidated that the aridity and openness of the environment reduce the number of phanerophytes.
In Mediterranean climates, the climatic factors most important in determining vegetation structure and composition appear to be the total amount of water available (in relation to potential losses) and the amount available in summer. In more continental Mediterranean areas, winter temperature also plays an important role. Reduced total water availability (in relation to evaporation) results in dominance by smaller plant forms. On the other hand, increased summer water stress results in smaller and harder leaves. The most striking feature of Mediterranean vegetation is its potential diversity of plant forms (Box 1982Box E.O. 1982. Life-form composition of Mediterranean terrestrial vegetation in relation to climatic factors. Ecologia Mediterranea 8: 173-181.).
Flowering plants show a variety of sex forms (Barrett 2002Barrett S. 2002. The evolution of plant sexual diversity. American Journal of Botany 101: 1588-1596.). Only 6% of angiosperms are polygamous individuals, whereas hermaphrodites are the most represented (Tomaszewski & al. 2018Tomaszewski C., Kulbaba M. & Harder L. 2018. Mating consequences of contrasting hermaphroditic plant sexual systems. Evolution 72: 1-15.). In the present study, most of the recorded species presented bisexual flowers (95.9%). Bisexual taxa are superior all over the world (Lewis 1941Lewis D. 1941. The evolution of sex in flowering plants. Biological Review of Cambridge, Philosophical Society 17: 46-67. ). Accordingly, they have variable possible chances of cross and self-pollination by autogamy (including cleistogamy) and geitonogamy giving many new individuals (Peedia, 2017Peedia. 2017. Difference between unisexual and bisexual flowers. Website: https://pediaa.com/difference-between-unisexual-and-bisexual-flowers/ [accessed: 14 Mar. 2022]). Bisexual flowers have parts such as bracts and pedicels that aid in insect attraction or organs that facilitate precipitation and uptake of pollen grains during animal pollination (Bawa & Beach 1981Bawa K. & Beach J. 1981. Evolution of sexual systems in flowering plants. Annals of the Missouri Botanical Garden 68: 254-274.). Bram & Quinn (2000)Bram M. & Quinn J. 2000. Sex expression, sex-specific traits and the effect of salinity on growth and reproduction of Amaranthus cannabinus. American Journal of Botany 87: 1609-1618. reported that dioecy is rare angiosperms. The low number of dioecious taxa could be interpreted in the view that these taxa suffer a reproductive handicap, because their populations contain fewer seed-producing individuals (Queenborough & al. 2009Queenborough S., Mazer S., Vamosi S., Garwood N., Valencia R. & Freckleton R. 2009. Seed mass, abundance and breeding system among tropical forest species. Journal of Ecology 97: 555-566.).
Most Mediterranean endemics flower from May to March, while a low percentage flower from August to January. In Egypt, plants start to grow from November when temperatures and evaporation are low, and humidity is high enough to make soil water content suitable for plant growth till reaching flowering stage in March and April (Heneidy 2010Heneidy S. 2010. Plant Atlas. The Botanic Garden (Alex). Faculty of Science, Alexandria University. Monsha’a Al Maaref, Alexandria.).
Croteau (2010)Croteau E. 2010. Causes and Consequences of Dispersal in Plants and Animals. Nature Education Knowledge 3(10): 1-12. described the role of movement factors like wind, water or animals in the passive dispersal of diaspores (i.e., seeds, spores or fruits) of flowering plants. These disseminules (i.e., diaspores) have some metamorphosis that help in transporting them from the parent plant to a new site. The predominance of ballochoric taxa (diaspores forcibly ejected from parent plant) may be due to the dry climate in Egypt. They are able to shatter when exposed to drought (El-Sheikh 1996El-Sheikh M. 1996. Ruderal plant communities of the Nile Delta region. Ph.D. Thesis, Tanta University, Tanta.). The commonness of pogonochoric taxa (diaspores with long hairs) reflects the suitability for wind dispersal in Egypt. The wide distribution of sarcochores (soft and fleshy diaspores) in the present study indicates that the principal mode of dissemination is the sarcochory by animals (i.e., zoochory).
Regarding the rarity forms, 60 taxa (92.3% of the total Mediterranean endemics) in the present study belonged to SNN cell, which means that these taxa are threatened. Chen & al. (2014)Chen Y., Yang X., Yang Q., Li D., Long W. & Luo W. 2014. Factors affecting the distribution pattern of wild plants with extremely small populations in Hainan Island, China. Plos One 5: 9-15. attributed the rarity of plants to internal causes such as genetic drift, pollination failure or unfeasibility of diaspores; or external causes such as human impacts or environmental factors like climate, soil or pathogens. Human impacts, roads, resorts or cultivation may be causes of habitat loss (Ahmed 2009Ahmed D. 2009. Current situation of the flora and vegetation of the Western Mediterranean Desert of Egypt. Ph.D.dissertation. Tanta University, Tanta.). On the other hand, four Mediterranean endemics (Anthemis microsperma, Bellevalia sessiliflora, Filago mareotica and Thymbra capitata) belonged to the SNA cell. One of the recorded taxa (Verbascum letourneuxii) was the only Mediterranean endemic belonged to SWN; their population numbers are decreasing leading to habitat reduction, which in turn may cause the taxon to be extinct and move to one of the rare cells (SNA or SNN) (Rabinowitz 1981Rabinowitz D. 1981. Seven forms of rarity. In Synge H. (ed.), The Biological Aspects of Rare Plant Conservation: 205-217. John Wiley and Sons Ltd, London.; Ahmed 2009Ahmed D. 2009. Current situation of the flora and vegetation of the Western Mediterranean Desert of Egypt. Ph.D.dissertation. Tanta University, Tanta.). High percentage of rare taxa (SNN, SNA and SWN), whereas absence of common taxa (LNA, LNN and LWA) are indicators that support a management plan to conserve Mediterranean endemics in Egypt.
CONCLUSION
⌅We report 57 Mediterranean endemic species in the Egyptian flora, the majority of which are found in the Mareotis subsector of the North African Mediterranean sub-region. We show that the most hospitable habitats for Egypt’s Mediterranean endemics are the coastal dunes and non-saline depressions. Therophytes make up for the majority of the endemic species and hermaphrodites are the most represented among sex forms. The majority of taxa have the highest flowering peak in April. Among dispersal types, ballochory is the most prevalent. Finally, the most frequent rarity type is SNN (small geographic range-narrow habitat-non abundant), indicating that most of the species are rare and very restricted, and they should be taken into consideration for conservation plans in the near future.