Ethnobotanical Study of Medicinal Plants Used in Central Macedonia, Greece

This work provides the ethnobotanical data concerning the traditional use of medicinal plants in Macedonia region (Northern Greece), which has, up to now, been poorly investigated. The aim of the present study was to collect, analyze, and evaluate information on the use of medicinal plants among different population groups living in Central Macedonia. The study was carried out in the area of two small cities, Edessa and Naoussa, and nearby villages. The ethnobotanical data were gathered through extensive and semistructured interviews. The informants belonged to different population groups living in the study areas and were involved, at least partially, in agriculture. Together with detailed reports on each species, data were also summarized by some indices, such as Fidelity Level (FL) and Informant Consensus Factor (Fic). A group of 96 informants was interviewed and 87 plant taxa with medicinal uses were cited. Medicinal plants are used to treat a wide range of diseases, in particular ailments of the respiratory tract and skin disorders. The importance of the traditional use of plants to cure and prevent common and some uncommon diseases had been highlighted. About 55% of medicinal plants mentioned by the informants had been previously reported to be sold in Thessaloniki herbal market as traditional remedies. Medicinal uses of some endemic taxa had been reported, e.g., Satureja montana subsp. macedonica, a member of the S. montana group restricted to Northern Central Greece, Origanum dictamnus, an endemic species of Crete, and six Balkan endemics, i.e., Achillea holosericea, Digitalis lanata, Helleborus odorus subsp. cyclophyllus, Sideritis scardica, Thymus sibthorpii, and Verbascum longifolium. Several differences in Traditional Ethnobotanical Knowledge (TEK) were observed in relation to social and cultural components of the population. Only 7 species (Crataegus monogyna, Hypericum perforatum, Matricaria chamomilla, Rosa canina, Sambucus nigra, Sideritis scardica, and Tilia platyphyllos) were commonly reported by all population groups, whereas 30 out of 87 taxa (34%) were exclusively mentioned by a single group. All groups are incorporated in the local society and do not identify themselves as members of different ethnic groups, although they try to preserve their distinctiveness by keeping their traditions and dialects. Nevertheless, our data show that the knowledge regarding the medicinal plant use was rarely accompanied by preservation of linguistic diversity concerning the plant names. This work contributes to improve the knowledge on the traditional use of plants in the folk medicine of a region like Central Macedonia where different population groups live together, partially maintaining their traditions. A part of data of this paper has been presented as posted at 112° Congress of Italian Botanical Society (IPSC), Parma 20-23 September 2017.


Introduction
The rural regions of southeastern Europe represent a unique social and environmental context for ethnobotanical studies, owing to the occurrence of a large mountainous area that is recognized as a hotspot for both biodiversity and cultural/ethnic/religious diversities. Medicinal plants have represented, for thousands of years, the only remedy for various diseases. Phytotherapy still maintains an important role in the treatment of many diseases in Greece. Despite this fact, only a few studies have explored the use of plants in Greek folk medicine while, on the contrary, in the neighboring region of the Balkan Peninsula very intensive and highly effective ethnobotanical studies were carried out in the last decade ( [1][2][3][4][5] and references therein). Ethnobotanical studies on traditional uses of plants and their products in Greece are relatively scarce. An old study concerning the knowledge of medicinal plants of Greece (Lawrendiadis, 1961) reported some data about most important plants used in folk medicine throughout Greece. More recent works have been mainly focused on the regions of Zagori [6,7], Thessaloniki [8][9][10], Crete [11], Mt. Pelion [12], and more recently on the Greek Islands of North Aegean Region [13]. In contrast, the regions of Edessa and Naoussa (Central Macedonia), where this study was carried out, remain poorly explored from an ethnobotanical point of view, despite their high floristic and vegetation diversity.
Our study area, Central Macedonia, lies in the core of the ancient Macedonian state (500-168 B.C.) and is the homeland of Alexander the Great. It was conquered by the Romans (168-284 B.C.), then was a part of the Byzantine Empire, and subsequently became a part of Ottoman Empire (from 1430), and, finally, it was incorporated into the Greek state in 1917 [14]. Centuries of foreign dominance and migrations had shaped the area into a cultural and linguistic mosaic. Until the beginning of 20th century, Greeks, Slavs, Bulgarians, Turks, and Vlachs were living together. The current population composition was formed after the Neuilly Treaty (1919) and mainly after the Greek-Turkish War in Asia Minor (1919)(1920)(1921)(1922) and the Lausanne Treaty (1923), when much of the Slav-speaking and all the Muslim populations left, and Greek populations from Asia Minor and Pontus moved in and settled [15]. Nowadays, the population consists mainly of five groups: (a) the Dopioi, i.e., the local people that remained after the migrations of the first quarter of 20 th century. Many of them (Slavophones or Slavo-Macedonians) speak a local Slavic-based dialect while others are Greek-speaking; (b) the Pontians, which come from the Greek population lived in the shores of the Black Sea since antiquity. Under the subsequent Ottoman rule, they survived relatively intact, preserving their customs and dialect (Pontian Greek), which is related to ancient Greek, until they were forced to leave their homeland (Day et al., 2002); (c) the Mikrasiates or prosfyges (meaning refugees), descendants of the Greeks of Asia Minor (Mikra Asia in Greek); (d) the Vlachs or Aromanians, people mostly living in montane region and occupied in animal husbandry, who speak a Latin-based language, having a long history of settlement in the study area. According to some historians, they are Latinized indigenous populations (Greeks, Illyrians, Thracians or Dardanias), due to the historical presence of the Roman military in the territory [16]. Many Romanian historians claim that the Aromanians were part of a Daco-Romanian migration from the north of the Danube [17,18]; (e) others, who recently moved to the region from various parts of Greece.
One of the most prominent differences of above populations groups is in their dialects, which are still used, particularly by the older people, as a second language after contemporary Greek. All groups are incorporated in the local society and do not identify themselves as members of different ethnic groups (REF). However, they define themselves based on their origin and try to preserve their distinctiveness by keeping, in a large degree, their customs, music, dances, dialects, and cuisine [19][20][21][22][23], (Winnfrith, 2001). Taking into account the lack of any published ethnobotanical information as well as the great cultural diversity of Central Macedonia, our aim is to survey medicinal plants and their uses and to find if significant differences concerning the use of medicinal plants still persist among the groups of inhabitants of the area.

Study Area.
Our survey was conducted in two cities, Edessa and Naousa, each with a population of c. 18.000 inhabitants and their nearby rural small villages ( Figure 1). The inhabitants are mostly occupied in agriculture and stock raising. The area is located at the foothills of Mt Vermio and Mt Voras. The two mountains, which are part of the Natura 2000 Network (GR1210001 and GR1240008, respectively), are characterized by a rich and diverse flora (> 1000 taxa were recorded on Vermio, and > 1500 on Voras), including several Greek and Balkan endemic species [24,25].

Methods.
The fieldwork was conducted during spring and summer in 2016 and 2017. The ethnobotanical data were gathered through extensive interviews, aimed to create open informal and semistructured interviews. Snowball sampling techniques were used to recruit 96 informants (37 men, 59 women). In snowball sampling, the first contact with the community is selected as a well-known expert; in a subsequent phase, the expert indicates another expert, and so on, until all the specialists in the community are covered [26]. The informants were selected proportionally to the occurrence of five groups within the local population: In particular, in the Naoussa municipality a total of 24 informants were selected (8 OTH, 3 MI, 9 PO; 2 DO and 4 VL), 20 coming from the town and 4 from the villages. In the Edessa municipality, there were a total of 72 (  as traditional costumes, music, and folk dances. Starting from Seventies the modern way of living has prevailed. However, at the same time, there was a turning towards folklore in every county town of Greece, including Central Macedonia. Cultural societies are formed with folklore dance groups and a recovery of the traditional music is still in progress [27]. Also in the study area several different folk traditions still persist among the group population, as shown by the presence of many Folklore Museums spreading in Central Macedonia (e.g., Vlach Folklore Museum, Folklore Museum of Edessa, History and Folklore Museum of Naoussa). For every informant we recorded personal information about age, gender, education level, profession, and population group. This distinction helped to note differences and similarities between citations based on different factors. The informants had personal experience in self-medication using herbs and had ethnobotanical knowledge because of family tradition or personal interest. Their age ranged between 24 and 94 years (mean = 59 years), educational levels included primary (30%), secondary (41%), and higher education (29%), jobs included employees (e.g., public employees, civil engineers), farmers, workers, and people involved in humanistic occupations (e.g., painter, teachers). All information was obtained after receiving an oral prior informed consent from the participants, according to the ISE (International Society of Ethnobiology) Code of Ethics. During the interviews, the informants were requested to indicate vernacular names of plants, parts of the plant used, association with other plants, folk uses, and preparation procedures. In many cases, data on specific recipes and their sources were included. Quite often the interviews took place in the village square or in the houses of the informants (Figure 2) where they also showed us traditional remedies that are currently used. Specimens of the plants were either given to us by the informants or collected from the wild, according to their instructions. The information collected refers to wild and cultivated species. The taxa were identified using standard Floras [24,25,28,29]. Nomenclature is according to Dimopoulos et al. [30]. Voucher specimens are deposited at the Herbarium of the Aristotle University of Thessaloniki (TAU).
The data gathered on plant uses were organized in citations and each citation coincided with a single row in a database created using Microsoft Excel. Then data were analyzed and compared with several ethnobotanical references, primarily based on a search in Scopus database, using the search string "ethnobotany and Greece". Following recent recommendations for reporting ethnobotanical field studies, primary data are presented in an unaltered form, allowing direct comparison between other similar researches [31]. In order to compare our results with the list of the most common medicinal plants used in Central Macedonia, in Table 1 we reported the species sold in the herbal market of the regional capital Thessaloniki [8]. Several ethnobotanical indices were adopted for interpreting the large quantity of information.

Quantitative Indices and Statistical Analysis.
To estimate the use variability of the species, we adopted the Informant Consensus Factor [32], which was calculated for each medicinal category. This index was calculated as follows: number of citations in a subcategory (n ur ) minus the number of taxa used in the same subcategory (n t ), divided by the number of citations minus one [33,34]: The value of this factor ranges from 0 to 1. A high F ic value indicates an agreement among the informants on the use of taxa within a medicinal subcategory. The F ic reflects homogeneity of information provided by different informants. The Fidelity Level index (FL) was also considered to indicate the informants' choice for a potential plant species to treat a given disease. It was calculated by the following formula [35]: where Np is number of use reports for a given species reported to be used for a particular ailment category and N is total number of use reports cited for any given species. Descriptive statistical analyses were carried out in R environment (vers. 3.4.0, R Core Team 2017) adopting a circlize package (vers. 0.4-2, [36]) and Venn Diagram package (vers. 1.6-19, [37]).

Medicinal Plants.
Our results showed that 87 medicinal plant species belonging to 48 families are used in the study area to treat several ailments. The surveyed species are listed in Table 1, where plant families and species within each family are cited in alphabetical order. In this table, for each taxon reported, data on scientific name, family, local name, part of plant used, medicinal use, and number of citations and if they are wild or cultivated are included. In the last column, it is also reported if the species has been previously cited in the study of Hanlidou et al. [8] on the herbal market in Thessaloniki (representing ca. 55% of the taxa cited in our work).
Noteworthy, the knowledge regarding the medicinal plant use was rarely accompanied by preservation of linguistic diversity concerning the plant names. In fact, only 6 out of 87 taxa were cited also under their dialect names. Accordingly, also in previous works on ethnobotanical use of plants in folk medicine in Greece, dialect names were seldomly reported [6]. Lawrendiadis (1961), speaking about common names of medicinal plants in Greece, referred that they are usually related to the part of the body on which they have curative effects or to the disease against which they can be used. For example, Tussilago farfara was called "vychion" from the Greek word "vyx" (cough) or Origanum dictamnus "stomachochorton" from the Greek words "stomachos" (stomach) and "chorton" (herb). More recently, Hanlidou et al. [8], referring to medicinal plants sold in the Thessaloniki market, reported for most taxa both commercial names and names in Dioscurides.
About 48% of the medicinal plants mentioned by the informants had been previously reported to be sold in Thessaloniki market as traditional remedies [8]. Seventeen of the 22 most relevant species, with at least 8 citations and high Fidelity Level (Table 3), are among them. The traditional shops and the street markets of this city include interesting information mainly derived from the inherited knowledge of the herbal sellers. Lamiaceae, the most frequently recorded family both in our study area and in the market of Thessaloniki, includes the greatest number of species mentioned for treating digestive, nervous, and respiratory diseases [10].
In many cases, the most common species reported for Central Macedonia for medicinal purposes are in agreement with those cited from other regions of Balkan Peninsula. For example, H. perforatum, M. chamomilla, S. nigra, R. canina, U. dioica, and C. monogyna were frequently cited by informants from Bosnia-Herzegovina [1] and from south Kosovo [4]. In Northern Macedonia Albanian informants reported H. tuberosum as a remedy for improving heart contractility, in addition to the use as human food [3]. In the same area, Sideritis scardica was reported mainly for treatment of respiratory diseases.

Plants Used for Respiratory Diseases.
In our study S. scardica is one of the most important (FL = 100%) plants cited for respiratory diseases, followed by Tilia platyphyllos, Sambucus nigra, Malva sylvestris, and Dactylorhiza sambucina. S. scardica is an aromatic plant very popular in Greece, Bulgaria, Albania, and North Macedonia where it is largely used in local cuisines. The species, together with several related Sideritis species, is known as "mountain tea", and in folk medicine of the Balkan countries, it is used for the preparation of decoctions mainly indicated to aid digestion, strengthen the immune system, and treat cold, flu, and allergies [6,38]. It is also employed against shortness of breath, sinus congestion, and even pain and mild anxiety [5,38,39]. It is worth noting that tubers of Dactylorhiza sambucina (as well as other Orchidaceae species) are collected from the wild and used to prepare a beverage, called "salepi", used as a cough remedy popular in several eastern Mediterranean countries [40]. Similar uses were reported for another Orchidacea, Orchis morio L., in south Kosovo where the tuber infusion is indicated as a remedy for influenza, stomach disorders, and wound healing [4].

Plants Used for Skin Diseases.
Among plants used to treat skin diseases Momordica charantia shows the highest FL (94%), while Hypericum perforatum (Figure 3(a)) reaches the highest number of citations (44). M. charantia or bitter melon is a tropical vegetable extensively used in Indian folk medicine as a remedy for diabetes. In Ayurveda, the fruit is considered as tonic, stomachic, stimulant, emetic, antibilious, and laxative. In addition, the fruit juice and/or a leaf tea is employed for malaria, colic, sores, wounds, and other skin diseases [41]. M. charantia fruit powder, in the form of an ointment (10% w/w dried powder in a simple ointment base), showed a statically significant response in terms of wound healing in rats [42]. In addition, recent studies showed that a M. charantia extract improves and accelerates the process of wound healing in rabbits in comparison with conventional creams used therapeutically [43]. It is a surprising fact that this tropical species has been incorporated in the traditional herbal medicine of the study area. In Macedonia we have previously reported the traditional preparation of an ointment made from the fragmented fruits of the plant that are immersed in olive oil and placed in the sun for 30-40 days. This ointment is indicated for the treatment of human and animal wounds [44]. The same use was referred by Turks living in south Kosovo, but in this case internal uses were also cited, including antidiabetic and anticancer [4].
A particular use of Cuscuta campestris (Figure 3(b)) was reported as a topic remedy against bee sting. Some of the aromatic plants used for the treatment of gastrointestinal    Mentha spicata L. Achillea millefolium L.   Paliurus spina-christi Mill. Equisetum arvense L. Plantago media L.   problems are Origanum majorana (Figure 3(c)), Matricaria chamomilla, and Mentha spicata. It is interesting to note that this latter species is included within plant taxa sold as "mint" in the market of Thessaloniki, where it is mostly recommended for common cold and cough [9]. O. majorana is widely used to treat colds and rhinitis [45,46], but it is also quoted for its antiulcer effect [47]. In addition, Castanea sativa catkins are widely used as a decoction for the treatment of diarrhea.

Plants Used for Cardiovascular Diseases.
Two species were found to be the most quoted (FL = 100%) for the treatment of cardiovascular diseases: Crataegus monogyna and Loranthus europaeus. C. monogyna is popularly known for its cardioprotective action reducing cardiovascular risk factors, such as hypertension and hypercholesterolemia [48,49]. In Macedonia this species is used as an infusion prepared with flowers, fruits, or leaves, but also as an alcoholic extract prepared from the fruits. L. europaeus (yellow-berried mistletoe) is a hemiparasite plant usually found on the branches of trees. The popular use of this plant for the treatment of cardiovascular problems has also been reported in Bosnia and Herzegovina [1]. In addition, a recent study on the ethnobotany of mistletoes species also cited the frequent use of this plant to treat cardiovascular disorders [50].

Plants Used for Nervous Diseases.
The use of Melissa officinalis and Valeriana officinalis to cure nervous system problems is well known [51,52], while that of Salvia officinalis is less common. In the traditional medicine of many European countries this species has been used mainly to treat mild dyspepsia, excessive sweating, and throat and skin inflammations [53], but the use in age-related brain disorders has also been reported [54]. In addition, some informants reported an uncommon use of Taraxacum officinale for treating nervous diseases, i.e., headache and insomnia. This use has been previously reported in an ethnobotanical survey of Zagori, Epirus, Greece [6].

Plants Used for Musculoskeletal Diseases.
A large number of species are used for musculoskeletal diseases, in particular against joint pains and rheumatism, such as Equisetum arvense (aerial parts), Arctium lappa (root), Cercis siliquastrum and Robinia pseudoacacia (flowers). The alcoholic extract of the sliced root of Tamus communis is also employed to treat muscular pain and inflammation. This species shows toxicity due to its content of calcium oxalates, saponins, tannins, and other substances; nevertheless, its anti-inflammatory and analgesic properties are well known [55] and its use in the treatment of rheumatisms has also been reported in the traditional medicine of Turkey [56] and Portugal [57].

Plants Used for Metabolic Diseases.
The most quoted plant for the treatment of metabolic diseases is Rosa canina (17 citations, FL = 85%), followed by Urtica dioica and Silybum marianum. In particular, R. canina is used as a decoction of fruits and flowers, syrup of boiled fresh fruits but also eaten raw as an immunostimulant, and for the prevention of the cardiovascular diseases.

Plants with Unusual Medicinal Uses or Used Only by a Single Population
Group. Some medicinal uses of plants seem to be particularly interesting because they have been infrequently or never reported. In addition, some of these uses concern toxic plants and rare or endemic species. Cuscuta campestris stems (Figure 3(b)) are applied topically against bee stings; Dopioi informants have exclusively reported this use. There are only a few ethnobotanical uses that have been detailed for this species: as purgative and against constipation in Saudi Arabia [58] and for its analgesic effect in the treatment of rheumatisms and headaches in Nepal [59].
In the present study, the use of a toxic species, Cynoglossum creticum, which contains pyrrolizidine alkaloids, has been cited [60]. The fruits of this plant have been reported to be eaten to treat a skin disease called "myrmecia" (Greek "myrmigkia"= ant), a word used allover Greece for the common skin warts caused by HPV (Human Papilloma Virus). The disease is characterized by the presence of small skin warts apparently similar to anthills. In the traditional medicine of India the aerial portion of Cynoglossum spp. is used against wounds, burns, ear infections, and cough for its antibacterial properties [61] and against fungal skin infections [62]. In Sardinia the root is used to prepare an emollient cream against burns [63], while leaves are directly applied as a cicatrizant or as a poultice to treat eczema [64]. In this study only informants from the group "others" have cited this particular use of C. creticum for the treatment of myrmecia.
Satureja montana subsp. macedonica, in addition to the common use of the flower infusion for the treatment of flu and cough, is also used in the study area by Pontians informants to relieve tinnitus and improve hearing. Generally, Satureja spp. have been used since ancient times as flavorings for food and for the treatment of various diseases; their essential oils have been documented for antimicrobial, antidiarrheal, fungicidal, and antioxidant activities [65].
However, the specific use for tinnitus treatment and for hearing improvement is particularly unusual and, to our knowledge, has never been previously reported.
Hyssopus officinalis is an aromatic plant commonly used in the traditional medicine of the Balkan Peninsula for its antiseptic, carminative, and spasmolytic properties [66]. The aerial parts of the species are used against chronic bronchitis and asthma [67,68]. Notably, the use of the decoction from the aerial parts as an analgesic to treat headache, cited in the present study, has never been previously reported.
Helianthus tuberosus is a naturalized species, native to North America, which was introduced in Europe during the XVII century. It was used at first as animal feed and subsequently as human food. Its tuber contains inulin as its main polysaccharide and is therefore indicated in the diet of diabetics. In the Carpathian basin it is also used in the treatment of asthma and heart problems [69]. Although it had not been highly reported in traditional medicine of the Mediterranean region, in the present survey, the decoction of the fragmented tuber was indicated against constipation. Similar uses have been described in Austria [70]. Also in south Kosovo the use of fresh tubers of H. tuberosum as human food was recently reported [4].

Traditional Ethnobotanical Knowledge among Different
Population Groups. The group "others" (i.e., informants who come from various parts of Greece) and Dopioi reported the highest number of species (53), followed by Pontians (42) and Mikrasiates (23 species). Vlach informants only cited 10 species. Only 7 species (Crataegus monogyna, Hypericum perforatum, Matricaria chamomilla, Rosa canina, Sambucus nigra, Sideritis scardica, and Tilia platyphyllos) were commonly reported by all population groups (Figure 4), whereas 30 out of 87 taxa (34%) were exclusively mentioned by a single group: 11 by Dopioi, 8 by Pontians, 7 by the group "others", and 4 by Mikrasiates. The species reported by Mikrasiates and Vlachs were mostly or fully shared with one or more of the groups. Notably, only 12% of taxa were referred with more than one name and only 6% were known with different dialectal names by different population groups (Table 1). It was demonstrated that in different Balkan areas that share similar flora but have different cultural or linguistic heritage, medicinal plants are used in very distinct ways [71][72][73]. For example, Mustafa et al. [4] found that Albanian, Bosniak/Gorani, and Turkish communities of Kosovan villages shared 22% of the taxa used for food and medicine, suggesting a hybrid character of the Kosovar plant knowledge. However, 42% of the plant species were only cited by a single ethnic group.   Figure 5 report the most important remediesinformant groups associations (> 20% of the total information reported for each disease category) observed, as a function of the main social categorizations of informants interviewed in our survey. When analyzing the distribution of disease categories in relation to population groups, some significant differences have been observed ( Figure 5(a)). The knowledge of less numerous groups (Vlachs and Mikrasiates) was equally distributed among disease categories, but less relevant with respect to that provided by the other groups. Plant species used against skin and respiratory diseases were highly cited by other informant groups, such as Pontians, Dopioi, and "others". For these latter about 50% of the information is related to these diseases. Dopioi showed important contribution in four remedy categories, being highly prevalent in the citations of treatments for muscular disorders. Similarly, the information delivered by Pontians represented nearly half of the total knowledge about the treatments for gastrointestinal diseases.

Plant Knowledge according to Sociologic Variables. The diagrams in
Although both male and female informants cited species that are used for different healing purposes, the ethnobotanical knowledge of females was more equally distributed in all use categories, whereas men mainly reported information on respiratory, genitourinary, and skin diseases ( Figure 5(b)).
Remedies for respiratory diseases were highly cited by informants, independently from their educational level, whereas the knowledge of medicinal plants used for treating nervous, skin, and gastrointestinal diseases was mainly reported by informants with a secondary level of education. Graduate informants had a major degree of knowledge about the treatment of metabolic disorders ( Figure 5(c)).
Independently from their job, many informants reported treatments of respiratory diseases ( Figure 5(d)). Moreover, in contrast with other job groups, the information reported by farmers was largely distributed among nearly all disease categories. Unexpectedly, no relevant differences were observed in relation to the age of the informants: both younger and older groups equally cited plant remedies for most of the diseases (data not shown). However, some associations were observed: persons < 40 years old frequently cited remedies for skin diseases, whereas plants used for treating genitourinary disorders were mainly cited by informants between 60 and 70 years old.

Conclusions
Our study highlights the importance of reporting the TEK typical of areas of Europe that have until now been poorly investigated. In fact, despite the large number of papers dealing with ethnobotany in the Balkans and southeastern Europe [74,75], Greece is still scarcely explored from an ethnobotanical point of view although it is characterized by a high floristic diversity. This is particularly true for regions like Central Macedonia where different population groups live together, maintaining most of their traditions. Information on species used in folk medicine of this region showed that most of them were wild and cultivated plants well known in the European ethnobotany for their healthcare and curative properties. Nevertheless some unusual uses were found, in particular concerning several toxic plants and rare or endemic species. Despite growing erosion of existing European tradition ethnobotanical knowledge, population groups in this region maintain some exclusive folk remedies such as the use of Cuscuta campestris against bee stings reported only by Dopioi informants and that of Satureja montana subsp. macedonica cited by Pontians to relieve tinnitus and improve hearing. Such local knowledge is culturally significant and can provide information for developing future Color bands summarize main relationships (> 20% of the total information) between each disease category and population groups. Numbers below the external segments in the graphs represent the total numbers of citations for each disease category and population group (e.g., in Figure 5(a), 40 citations were overall reported for plants used as a remedy for muscular-skeletal diseases, whereas a total of 132 citations were provided by Dopioi).
researches and promoting ethnopharmacological advances. When taking in account differences among the studied population groups, only 7 plant species were commonly reported by all groups, whereas 34% of plants were exclusively mentioned by a single group. This observation supports the idea that some differences are maintained among population groups, although the knowledge on the medicinal plant use is not accompanied by preservation of linguistic diversity concerning the plant names. Furthermore our analysis of plant knowledge according to sociologic variables contributes to a better understanding of factors that affect changes in plant uses and perceptions in different sociocultural contexts.

Data Availability
The ethnobotanical data used to support the findings of this study have been deposited in the Department of Pharmacognosy and Natural Products Chemistry, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens.

Conflicts of Interest
The authors declare that they have no conflicts of interest.