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Contribution to the flora of the Maltese Islands: Euphorbia subg. Chamaesyce and Euphorbia exigua s. l. (Euphorbiaceae)



The identity and the taxonomic treatment of the species belonging to Euphorbia subg. Chamaesyce occurring on the Maltese Islands were not adequately studied both in historical and recent literature. Apart from the native sand dune species Euphorbia peplis, all records have been previously attributed to the cosmopolitan weedy species E. maculata and E. chamaesyce. This work provides the first taxonomic synopsis based on the examination of 53 specimens collected from Malta and Gozo between 2014 and 2017. The study ascertained the occurrence of six species, of which E. serpens, E. prostrata and E. hypericifolia are first reported from the Maltese Islands. Discussion on the taxonomy, origin, ecology and invasiveness of these species is provided, together with photos and an identification key. Moreover, taxonomic studies on E. exigua s. l., belonging to subg. Esula, sect. Exiguae, have been carried out on Maltese material and discussed. E. exigua var. pycnophylla, originally described as endemic of the Maltese Archipelago and recorded afterwards on the Sicilian island of Lampedusa, bears no significant morphological trait which allows to clearly distinguish it from the nominal variety. No differences in fruit and seed morphology resulted when the two varieties were compared and the slight differences present in the habit of the plant and the arrangement of leaves has been judged to be of ecotypic origin, hence justifying the lumping of this variety into the single and variable taxon E. exigua.


Euphorbia, Chamaesyce, Euphorbia exigua, Flora of Malta, Mediterranean Flora, Eudicots

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Benedì, C. & Orell, J.J. (1992) Taxonomy of the genus Chamaesyce S.F. Gray (Euphorbiaceae) in the Iberian Peninsula and the Balearic Islands. Collectanea Botanica (Barcelona) 21: 9–55.

Boissier, E. (1862) Euphorbieae. In: De Candolle, A. Prodomus Systematis Naturalis Regni Vegetabilis Vol. 15, part 2. Imprimerie generale de Ch. Lahura, Paris. pp. 3–188.

Borg, J. (1927) Descriptive flora of the Maltese Islands. Government Printing Office, Malta. 846 pp.

Brullo, C. & Brullo, S. (2009) Considerazioni su alcune specie critiche della flora sicula. In: Peccenini, S. & Domina, G. (Eds.) Gruppi critici della Flora d’Italia. Comunicazioni. Società Botanica Italiana, Gruppo per la Floristica, Rome, pp. 43−44.

Bruyns, P.V., Mapaya, R.J. & Hedderson, T. (2006) A new subgeneric classification for Euphorbia in southern Africa based on ITS and psbA-trnH sequence data. Taxon 55 (2): 397–420.

Candolle de, A.P. & Lamarck, J.B.A.P. (1815) Flore Francaise, ou Descriptions Succinctes de Toutes les Plantes qui Croissent Naturellement en France. Vol. 6. 3rd ed. Desray, Paris. 388 pp.

Casha, A. (2013) Flora of the Maltese Islands: An Introduction. Vol. 2. Coral Print, Malta. 313 pp.

Cassar, L.F. & Stevens, D.T. (2002) Coastal sand dunes under siege. A guide to conservation for environmental managers. International Environment Institute of the University of Malta, Malta. x + 194 pp.

DAISIE—Delivering Alien Invasive Species Inventories for Europe (2008) European Invasive Alien Species Gateway. Available from (accessed 20 December 2017)

Ellison, M.A., Davis, C.C., Calie, P.J. & Naczi, F.C. (2014) Pitcher Plants (Sarracenia) Provide a 21st-Century Perspective on Infraspecific Ranks and Interspecific Hybrids: A Modest Proposal for Appropriate Recognition and Usage. Systematic Botany 39 (3): 939–949.

Euro+Med (2006–2017) Euro+Med PlantBase - the information resource for Euro-Mediterranean plant diversity. Published on the Internet: (accessed 29 May 2018)

Giardina, G., Raimondo, F.M. & Spadaro, V. (2007) A catalogue of plants growing in Sicily. Bocconea 20: 5–282.

Grech Delicata, G.C. (1853) Flora melitensis, sistens stirpes phanerogamas in Melita insulisque adjacentibus hucusque detectas secundum systema Candolleanum digestas. Melitae. W. Franz Publishers, Malta. 49 pp.

Gussone, G. (1843) Florae Siculae Synopsis, exhibens plantas vasculares in Sicilia insulisque adjacentibus huc usque detectas secundum systema Linneanum dipositas. Vol. 1. Ex Typis Tramater, Naples. 582 pp.

Haslam, S.M., Sell, P.D. & Wolseley, P.A. (1977) A Flora of the Maltese Islands. University Press, Malta, 560 pp.

Heywood, V.H., Brummit, R.K., Culham, A. & Selberg, O. (2007) Flowering plant families of the world. Firefly Books, New York, 424 pp.

Humboldt von, A., Bonpland, A. & Kunth, K.S. (1817) Nova genera et species plantarum. Vol.2. Librariae Graeco-Latino-Germanico, Paris, 404 pp.

Hyde, M.A., Wursten, B.T., Ballings, P. & Coates Palgrave, M. (2017) Flora of Zimbabwe: Species information: Euphorbia serpens. Available from: (accessed 12 December 2017)

Jeanmonod, D. & Gamisans, J. (2007) Flora Corsica. Édisud, Aix-en-Provence, 920 pp.

Kramer, K.U., Westra, Th., Kliphus, E. & Gadella, J. (1972) Floristic and cytotaxonomic notes on the Flora of the Maltese Islands. Acta botanica neerlandica 21 (1): 54–66.

Koch, K. (1846) Beiträge zur Flora des nördlichen Küstenlande von Kleinasien. Linnaea 19: 1–67.

Lagasca, M. (1816) Genera et species plantarum, quae aut novae sunt aut nondum recte cognoscuntur. Typographia Regia, Madrid, 35 pp.

Lamarck, J.B.A.P.M. de (1779) Flore Françoise, ou Descriptions Succinctes de Toutes les Plantes qui Croissent Naturellement en France. Vol. 3. De L’Impremerie Royale, Paris. 654 pp.

Lanfranco, G. (1969) A Field Guide to the Wild Flowers of Malta. Progress Press, Malta. 83 pp. + 65 plates.

Lanfranco, E. & Bonnett, G. (2015) Nature Guide Series: Wild Flowers of the Maltese Islands. BDL Publishing, Malta. 208 pp.

Linnaeus, C. (1753) Species Plantarum Tomus 1+2. Laurentii Salvii, Holmiae [Stockholm]. 1200 pp.

Linnaeus, C. (1767) Systema Naturae Editio duodecima, reformata, Tomus 2. Laurentii Salvii, Holmiae [Stockholm], 736 pp.

Mifsud, S. (2002–2014) Euphorbiaceae. In: Mifsud, S. (Ed.) Malta Wild Plants Website. Available from: (accessed 20 December 2017)

Minissale, P. & Spampinato, G. (1988) Segnalazioni di piante nuove per la flora di Lampedusa. Informatore Botanico Italiano 19 (2): 136–143.

Nimis, P.L., Bagella, S., Caria, M.C., Filigheddu, R., Moro, A., Pittao, E. & Martellos, S. (2018) Euphorbia exigua L. subsp. exigua. In: Guida alla flora degli stagni temporanei della Sardegna [online]. Available from: (accessed 10 February 2018)

Pahlevani, A.H., & Akhani, H. (2011) Seed morphology of Iranian annual species of Euphorbia (Euphorbiaceae). Botanical Journal of the Linnean Society 167: 212–234.

Pahlevani, A.H. & Riina, R. (2011) A synopsis of Euphorbia subg. Chamaesyce (Euphorbiaceae) in Iran. Annales Botanici Fennici 48: 304–316.

Parlatore, F. (1869) Flora italiana; ossia, Descrizione delle piante che crescono spontanee o vegetano come tali in Italia e nelle isole ad essa aggiacenti; disposta secondo il metodo naturale. Vol. 4. Part 2. Tip. Le Monnier, Firenze. 623 pp.

Peirson, J.E., Bruyns, P.V., Riina, R., Morawetz, J.J. & Berry, P.E. (2013) A molecular phylogeny and classification of the largely succulent and mainly African Euphorbia subg. Athymalus (Euphorbiaceae). Taxon 62 (6) : 1178–1199.

Persoon, C.H. (1807) Synopsis Plantarum seu Enchiridium Botanicum Vol. 2. Treuttel et Wurth, Tubingae. 656 pp.

Pignatti, S. (1982) Flora d’Italia. Vol. 2. Edagricole, Bologna. 732 pp.

Raab-Straube (von), E. & Raus, T. (2015) Euro+Med-Checklist Notulae, 4 [Notulae ad floram euro-mediterraneam pertinentes 33]. Willdenowia 45 (1): 119–129.

Rafinesque, C.S. (1817) Second decade of undescribed American plants. The American monthly magazine and critical review 2: 119–120.

Reichenbach, H.G.L. (1790) Elementa Botanica Genera Genuina, Species Naturales Omnium Vegetabilium Detectorum Eorumque Characteres Diagnosticos ec Peculiares Exhibentia, Secundum Systema Omologium seu Naturale, Evulgata. Cum Tabulis Separatis Tomus 2. Societatis Typographicae Neowedensis, Bossange, 460 pp.

Riina, R., Peirson, J.A., Geltman, D.V., Molero, J., Frajman, B., Pahlevani, A., Barres, L., Morawetz, J.J., Yasaman, S., Zarre, S., Kryukov, A., Bruyns, P.V. & Berry, P.E. (2013) A worldwide molecular phylogeny and classification of the leafy spurges, Euphorbia subgenus Esula (Euphorbiaceae). Taxon 62 (2): 316–342.

Sciandrello, S., Giusso del Galdo, G. & Minissale, P. (2016) Euphorbia hypericifolia L. (Euphorbiaceae), a new alien species for Italy. Webbia 71 (1): 163–168.

Silva, O.L.M., Cordeiro, I. & Caruzo, M.B.R. (2015) Seed morphology in Euphorbia and its taxonomic applications: a case study in Saõ Paulo, Brazil. Brazilian Journal of Botany 39 (1): 349–358.

Smith, A.R. & Tutin, T.G. (1968) Euphorbia. In: Tutin, T.G., Heywood, V.H., Burges, N.A., Valentine, D.H., Walters, S.M. & Webb, D.A. (Eds.) Flora Europaea. Vol. 2. Rosaceae to Umbelliferae. Cambridge University Press, Cambridge, UK, pp. 213–226.

Sommier, S. (1908) Le Isole Pelagie Lampedusa, Linosa, Lampione, e la loro Flora. Con un elenco completo delle piante di Pantelleria.Stabilimento Pellas, L. Chiti Successori, Firenze, 345 pp.

Sommier, S. & Caruana Gatto, A. (1915) Flora melitensis nova.Stabilimento Pellas, L. Chiti Successori, Firenze, 530 pp.

Steinmann, V.W., Morawetz, J.J., Berry, P.E., Peirson, J.A. & Yang, Y. (2016) Euphorbia Linnaeus sect. AnisophyllumRoeper. In: Flora of North America Editorial Committee (Eds.) Flora of North America North of Mexico.Vol. 12. New York and Oxford. Available from: (accessed 15 December 2017)

Stuessy, T.F. (2009) Plant Taxonomy: The Systematic Evaluation of Comparative Data. 2nd edition. Columbia University Press, New York, 568 pp.

Tabone, T.J. (2007) A list of records of some rare vascular flowering plants occurring in the Maltese Islands (Central Mediterranean). Central Mediterranean Naturalist 4 (3): 181–189.

Tabone, T.J. (2008) A list of records of some rare vascular flowering plants occurring in the Maltese Islands (Central Mediterranean). Central Mediterranean Naturalist 4 (4): 311–337.

Thellung, A. (1907) Die in Europa bis jetzt beobachteten Euphorbia-Anen. Der Sektion Anisophyllum. Bulletin de l’Herbier Boissier Ser. 2, 7: 741–772.

The Plant List (2013) Version 1.1. Available from: (accessed16 December 2017)

Tison, J.-M. & Foucault, B. (2014) Flora Gallica Flore de France. Biotope Editions, Mèze, 1195 pp.

Tison, J.-M., Jauzein, P. & Michaud, H. (2015) Flore de la France méditerranéenne continentale. Naturalia, Turriers, 2078 pp.

Tropicos (2017) Missouri Botanical Garden. Available from: (accessed 12 December 2017)

Weber, H.C. & Kendzior, B. (2006) Flora of the Maltese Islands. A field Guide. Margraf Publishers, Weikersheim, 384 pp.

Willdenow, C.L. (1799) Species Plantarum. Editio Quarta. Vol. 2. Part 2. Impensis G. C. Nauk, Berlin. pp. 835–1430.

Yang, Y., Riina, R., Morawetz, J.J., Haevermans, T., Aubriot, X. & Berry, P.E. (2012) Molecular phylogenetics and classification of Euphorbia subgenus Chamaesyce (Euphorbiaceae). Taxon 61: 764–789.

Zerapha, S. (1827) Florae Melitensis Thesaurus, sive plantarum enumeratio, quae in Melitae Gaulosque insulis aut indiginæ aut vulgatissimæ occurrunt: Addita, præter characterem specificum, citatione figurarum, Plantarum rariorum statione, nec non singularium specierum efflorescentia, duratione &c. Fasciculus I. Malta. 36 pp.


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