Biodiversity Journal , 2015, 6 (4): 773–788 New contribution on the vascular flora of the Aegean Island of Chalki (Archipelago of Rhodes, Aegean Sea) Cristina Cattaneo¹* & Mauro Grano² 1Via Eleonora d’Arborea 12, 00162 Roma, Italy; e-mail: [email protected] 2Via Valcenischia 24, 00141 Roma, Italy; e-mail: [email protected] *Correspondig author ABSTRACT This note is an integration to the study, started in August 2014, of the vascular flora of the Island of Chalki. Special emphasis has been done on the chasmophytic flora which has shown a remarkable richness in terms of endemic species, common to the island and to the SE Aegean Sea, including the west coast of Turkey. Some limestone north-facing cliffs, located on the northern and southern sides of Chalki, have been investigated. It has been tried to develop a reasoned reading on the micro-distribution of the chasmophytic flora of Chalki, taking into account parameters such as morphology of the cliffs, altitude, solar radiance, grazing. Grazing has especially proved a substantial factor, that has affected on confinement of some species in inaccessible sites such Erica manipuliflora Salisb. (Ericaceae) and Medicago arborea L. (Fabaceae), which are not necessarily chasmophytic species. The almost exclusive finding of chamaephytes and hemicryptophytes in these types of habitats characterized by extreme edaphoclimatic conditions, showed the remarkable specialization as well as the rarity of these species. KEY WORDS Chalki; chasmophytic flora; grazing; suffruticose chamaephyte; vertical cliffs. Received 16.09.2015; accepted 09.11.2015; printed 30.12.2015 INTRODUCTION ousa, Strongyli, Agios Theodoros, Maelonisi (Ili- adis, 1950). The Aegean Island of Chalki is part of the Do - Chalki appears as a mountainous and rocky is - decanese Archipelago (SE Aegean); is located land, consisting mainly of massive and hard lime - between the islands of Rhodes (SW), Tilos (SE) and stone, ceroid limestone (that give rise to rendzinas) Karpathos (NE). Its geographical coordinates are: and siliceous limestone (Desio, 1923; 1924a; 36 o13'44.49" N;27 o34'18.74" E. Has a length of 10 1924b; 1928). The highest peak is represented by km, a width of 4 km and an area of 28,125 km² (Fig. Mount Profitis Ilias (578 m). The coastline is very 1). Administratively Chalki is part of Rhodes articulate and rich in gorges and steep limestone Regional Unit. The Municipality of Chalki includes cliffs mainly in the north and southsides. The island several uninhabited offshore islands like Alimia, is essentially arid, and lacks of superficial hydro - Krevati, Nisaki, Kolofona, Pano Prasouda, Trag- graphy with an extremely low presence of under - 774 CRISTINA CATTANEO & M AURO GRANO ground water. The climate of Chalki is dry and GPS III Plus. The names of the local places men - warm with strong northern winds. The absence of tioned in the text, faithfully follow the map of a weather station on the island, did not allow the Chalki produced by Anavasi (2008). elaboration of climate data. The first botanical The floristic data presented in this article come researches on Chalki were made during the 19th from collections and field observations made by century, starting with Mayor & Barbey (1894). the authors in Chalki in two different times: in Investigations of Rechinger (1943) Rechinger & August 2014 and April 2015. The field investiga - Rechinger (1951) and of the zoologist Werner fol - tions carried out in April, lasted four days. It was lowed. An important contribution to the knowledge possible integrate the previous checklist, relatively of Chalki’s flora was given by Carlström (1987), in modest, due to the extreme drought of the research a study project on the flora and phytogeography period. For the data collected in August 2014 see of SE Greece and SW Turkey. To Tzanoudakis & Cattaneo & Grano (2015). Specimens of the col - Kollmann (1991) is referred the discovery of a new lected species are deposited in the herbarium of the species for the island: Allium chalki . Also in the authors: Cattaneo (HCC). For the determination same year Rackham & Vernicos (1991) studied the of plant material was mainly used Rechinger ecological history and future perspectives of Chalki. (1943, 1949), Rechinger & Rechinger (1951), Finally, the investigations carried out by Biel & Tan Davis (1965-1988), Tutin et al. (1964-1980, 1993), (2009), led to the discovery of some new taxa for Pignatti (1982), Strid & Tan (1997, 2002, 2009), the island. Recently was published a contribution Lafranchis & Sfikas (2009), Dimopoulos et al. on orchid flora of Chalki, where is described a new (2013). species for the island: Ophrys chalkae (Hirth & For the taxonomic-nomenclatural definition of Spaeth, 2010). the taxa have been taken into consideration Greuter et al. (1984-1989), Dimopoulos et al. (2013) and the database "Euro + MedPlantbase (http: //www. MATERIAL AND METHODS emplantbase.org/home.html). The division and the denomination of the families were taken from For detecting altitude and geographic coordin- Dimopoulos et al. (2013). In the vascular plant ates has been used a satellite tracking device Garmin inventory families, genera and species are in al- Figure 1. Map of Chalki Island, Archipelago of Rhodes, Aegean Sea. New contribution on the vascular flora of the Aegean Island of Chalki (Archipelago of Rhodes, Aegean Sea) 775 ABBREVIA - CHOROLOGICAL CHOROLOGICAL CATEGORY DESCRIPTION TION CATEGORY BK Balkan Taxa restricted to Balkan countries, occasionally extending to adjacent parts of SE Europe BI Balkan-Italian Taxa restricted to Balkan countries and Italy BA Balkan-Anatolian Taxa restricted to Balkan countries and to Asia minor (Anatolia), occasionally extending to S Ukraine (Crimea) adjacent Caucasian countries (Georgia, Armenia) or N Iraq EM E Mediterranean Taxa restricted to the E Mediterranean, occasionally extending to S Italy or adjacent Caucasian countries WM W Mediterranean Taxa restricted to the W Mediterranean, extending to eastern countries Me Mediterranean Taxa with a circum-Mediterranean distribution including Portugal, occasionally extending to the Caucasus area and N Iran MA Mediterranean-Atlantic Taxa restricted to maritime W Europe and the Mediterranean ME Mediterranean-European Taxa restricted to the Mediterranean and temperate Europe, occasionally extending to NW Africa and the Caucasus area MS Mediterranean-SW Asian Taxa distributed in one or more Mediterranean countries and extending to SW and C Asia Eu European Taxa with a distribution all over Europe EA European-SW Asian European taxa (occasionally reaching N Africa) with a distribution extending to SW Asia, occasionally reaching C Asia ES Euro-Siberian Taxa with main distribution in temperate Eurasia (occasionally reaching the Caucasus area) Pt Paleotemperate Taxa of extratropical Eurasia including the Himalaya and E Asia, not (or at most marginally) extending to North America ST Subtropical-Tropical Taxa widespread in the warmer regions of both hemispheres Co Cosmopolitan Taxa distributed in all continents Endem. Endemic Taxa with a distribution restricted to the territory of Greece Neotrop. Neotropical Taxa with wide distribution Pantrop. Pantropical Taxa with wide distribution Table 1. Chorological categories used in the checklist (extrapolated by Dimopoulos et al., 2013). 776 CRISTINA CATTANEO & M AURO GRANO phabetic order. Life-form categories are based on radiance; C) Chasmophytic species that grow Raunkiaer (1934), while chorological types (Table among different kind of rocks, at altitudes below 1) are based mainly on information provided by 100 m, which present heterogeneous requirements Dimopoulos et al. (2013). Plant species introduced of solar radiation (Table 2). on the island were divided into cultivated (CULT), casual (CAS), naturalized (NAT) and invasive Investigated sites (INV). Where possible is provided an estimate of the local frequency of taxa listed by the initials F During the second botanical survey carried out (= frequently), R (= rare) and L (= localized). The in April 2015, were examined more carefully cliffs species collected in the second time, are marked in located on north side of Chalki in the sites of the floristic inventory by an asterisk (*). Klisoures, Kamenos Spilios, Areta and cliffs located in the south of the island in sites of Pano and Kato Gremos. These cliffs have shown a remarkable RESULTS floristic richness in terms of endemics. However, at the time of the investigation several species had not As previously mentioned (Cattaneo & Grano, yet reached blooming, so the identification was not 2015), Chalki looks like a calcareous island, with a possible. Many chasmophytic species, in fact, de - maximum height that do not exceed 600 m above veloped adaptive strategies in harsh environments, sea level and with few flat areas located in the cent- such as an increased lignification and delay in ral part of the island. Probably the most interesting reaching the reproductive stage, enabling them aspect of the island is given by vertical cliffs of greater longevity (Davis, 1951). massive limestone and deep gorges along the coa - stline, except for the oriental side. The presence of Klisoures and Kamenos Spilios these vertical cliffs allowed the growth of a rare and highly specialized chasmophytic flora. Several The north-facing limestone cliffs of Klisoures, species are endemic with a distribution area limited are characterized by a considerable verticality. They to the island and to the SE Aegean, including W are located