Small regions as key sources of traditional knowledge: a quantitative ethnobotanical survey in the central Balkans

Abstract

Background

Starting from the idea that unexplored areas may yield new and different ethnobotanical information, we performed a survey of traditional uses of plants in two neighboring districts situated in east Serbia (Bor and Aleksinac), both lacking in previous ethnobotanical reports, but characterized by an interesting history and culture, together with some specific features. In this study, we hypothesized that such small and specific areas could be of high ethnobotanical importance.

Methods

Semi-structured interviews were used with 155 informants. Relative cultural importance (RCI) indices, such as the frequency of citation (FC), relative frequency of citation (RFC), relative importance index (RI), informant consensus factor (ICF-FIC), use value (UV), fidelity level (FL) and Jaccard index (JI), were calculated, and principal coordinate analysis (PCoA) was performed.

Results

In this study, 2333 use-reports and 114 plants were recorded. Of the 101 medical herbs, 33 are included in the European Pharmacopoeia Edition 8.0. The most frequently used mode of preparation was as an infusion (50.0%), while leaf (44.7%) was the most used plant part. The highest FC and RFC values were recorded for Hypericum perforatum L. (13.1 and 0.2, respectively), while the highest RI was documented for Urtica dioica L. (1.0). ICF and FL indices showed important differences among selected groups of informants. The PCoA showed three homogeneous plant groups. Plants were mostly used for the treatment of digestive (49.1%), circulatory (41.2%) and respiratory system disorders (35.1%). Thirty-seven (32.5%) herbs were used for human nutrition, 14 (12.3%) in veterinary medicine, 17 (14.9%) in rituals and ethnoculture, while 24 (21.0%) for miscellaneous purposes. The highest degree of similarity was determined with studies conducted in close proximity. Four species are new to Balkan ethnobotany. New uses for some well-known plants are highlighted.

Conclusion

The study indicated that small and specific areas in the Balkans may be an important reservoir of ethnobotanical knowledge.

Background

Medicinal plants have an important significant role in the everyday life of rural people, particularly in developing countries. It is estimated that nearly 70 000 plant species are used for medicinal purposes today [1]. Wild plants are an important source of starting material for the synthesis of conventional drugs. About 80% of 122 plant-derived drugs are linked with their original traditional uses [2]. It was noted that 11% of the 252 essential drugs (listed by the World Health Organization—WHO) are exclusively of angiosperm origin [3]. Moreover, it is well established that most natural-based remedies exhibit fewer side effects compared to synthetic drugs. Collecting knowledge about plant species and their various uses is of great importance for the preservation of cultural heritage and the conservation of plant diversity [4].

The Balkan Peninsula is a biogeographic region with an exceptional floristic richness [5]. It is known that the ca. 8000 vascular plant species recorded for the Balkans include 2600 to 2700 endemics [6]. Serbia is located in the north-central region of the Balkan Peninsula and, according to recent data, has a flora of 4246 taxa [7] of which 1000 to 1500 species are used as foodstuffs, spices, food preservatives, medicinal plants, natural dyes or additives [8]. About 700 medicinal plant species are listed in Serbia [9]. People in Serbia have been relying on plants for various purposes since ancient times, as documented in old medieval Serbian therapy handbooks, known as the Hodosh Codex and the Chilandar Medical Codex [10, 11]. In many Balkan countries, people still practice herbal traditional medicine, where the purpose and way of use depend on cultural, historical and ethnic influences. However, depopulation, aging, migration, economic devastation and abandonment of villages and underdeveloped regions in Serbia and the entire Balkan region have resulted in a dramatic loss of ethnobotanical knowledge, in addition to a loss of plant genetic resource diversity [8]. In recent years, ethnobotanical investigations in Serbia were intensified [12,13,14,15,16,17,18,19,20]. Among the most recent studies, the differences in the traditional use of plants between rural and urban populations of different nationalities in the central Balkan region were reported [21], highlighting the value of traditional knowledge and of old practices which are still performed. Due to multiethnicity and complex historical background, Serbia represents a reservoir of cultural, linguistic, religious and other diversities. We consider that there are still many unexplored areas or regions with hitherto unrecorded ethnobotanical information, useful species, and new medicinal uses for known herbs.

Starting from the idea that unexplored areas may yield new and different ethnobotanical information, we performed a survey of traditional uses of plants in two neighboring districts situated in east Serbia (Bor and Aleksinac), both lacking in previous ethnobotanical reports, but characterized by an interesting history and culture, together with some specific features (rural, abandoned, economically devastated and with high migration rate). In this study, we hypothesized that such small and specific areas could be of high ethnobotanical importance and we set the following goals: (1) to collect data on the traditional uses of wild plants for medicine, human and domestic animal nutrition, veterinary medicine, folk and religious rituals, ethnoculture and other purposes; (2) to use relevant ethnobotanical indices and appropriate statistical methods to evaluate the obtained data; (3) to compare ethnobotanical knowledge between people of the two districts, between usage of plants by men and women, as well between inhabitants of cities and villages; (4) to compare our results with other ethnobotanical studies of neighboring regions conducted in Serbia and Balkans; (5) to report on new species records and new use-records not previously reported for Serbia and the Balkans; and (6) to suggest possible ways in which valuable traditional botanical knowledge can be preserved as an important part of general cultural heritage.

Methods

Research area

The research was carried out in Aleksinac and Bor districts in Eastern Serbia. Aleksinac is located in the Aleksinac basin (Serbian: Aleksinačka kotlina), in the lower stream of the South Morava river [22]. The area is known for former coal mining and high resources of oil shale estimated at about two billion tons in total reserves [23]. However, the mine was closed after an accident occurred in 1989 [24], after which no mining was performed anymore. Aleksinac is very near to Sokobanja, known among the biggest medicinal plants collecting centers in Serbia. Bor district is located in Timok Krajina in the eastern Serbia [25]. Initially, Bor was a village, but over time, in the mid-twentieth century, it developed into an urban area. This area is known for its copper and gold deposits [26]. The opening of the mine in 1903 caused the development of Bor as an industrial center in east Serbia in the mid of the last century [25]. During a time, mining started to bring more losses than benefits and the area was gradually depopulated and marginalized. Quite recently, mines were bought by a Chinese strategic partner (Zijin Mining). Although both areas suffered certain environmental and biodiversity damages, it is supposed that local inhabitants still rely on traditional herbal remedies and folk medicine. According to data acquired by the census in 2011, both districts exhibit a strong depopulation trend. The number of inhabitants in the Aleksinac district is around 16.700 and they are quite exclusively of Serbian nationality (91.7%). In Bor district, there are nearly 34.200 residents of Serbian ethnic majority (72.9%). The so-called Vlachs (“Vlah” in Serbian) of Romanian origin represent the second biggest ethnic group (13.8%), whereas Roma, Macedonian and Romanian minorities are fairly less represented [27, 28]. It is thought that Vlachs still tightly adhere to their cultural customs, speaking both Vlach (Daco-Romanian varieties) and Serbian language. The Vlach minority was recognized as the ethnic group from the earliest censuses in Serbia—since 1959, and it is strictly linked to the eastern Serbia in difference to Romanian minority settled mostly in the north of the country [29]. Religion and rituals resemble Serbian traditional customs. They also celebrate family saints (“slava”) which are in accordance with Serbian Orthodox Church tradition [30]. The number of interviewed respondents corresponded with the total number of district inhabitants.

Ethnobotanical survey

Two towns and nine surrounding villages of both regions were included in the study. In the Aleksinac district, the city Aleksinac and the surrounding villages Jakovlje, Kamenica, Loznac and Ljupten were surveyed. In the Bor district, the city Bor and the surrounding villages Brestovac, Bučje, Krivelj, Oštrelj and Slatina were investigated. The research was conducted during May–July 2019. Groups of local inhabitants in both municipalities (155 in total; 55 informants from Aleksinac and 100 informants from Bor region) were interviewed using semi-structured questionnaires. The proportion of respondents from the two districts clearly corresponded with the total number of their inhabitants. The youngest and the oldest respondents were at age of 23 and 86, respectively. In total, 113 were women and 42 were men. Respondents were chosen with no special selection criteria. Middle-aged and older participants (which made up the majority of respondents) had a high level of experience in the use and application of wild plants and therefore were more willing to take part in our research. The local recipes for the preparation of herbal remedies were additionally recorded.

There is a difference between these two areas in the ethnicity of informants reflecting the general ethnic structure of surveyed regions. Population heterogeneity was more pronounced in Bor city and surrounding villages; 77 informants were Serbs, 19 were Vlachs, 2 were Macedonians, 2 were Bulgarians and 1 informant was Montenegrin. On the other hand, there is ethical uniformity in Aleksinac city and the surrounding area: out of the total of 55 interviewed inhabitants, 54 were Serbs and 1 was Montenegrin. Thanks to interviews, the data about the local names of plants, methods of collecting and primary processing of plant material, as well as plant parts in use and way of preparation of the herbal remedies, were recorded. The information on the traditional use of herbal drugs in folk and veterinary medicine, human and animal nutrition, traditional customs and folk beliefs, and uses of plants for other purposes was recorded. The plants were authenticated by Prof. Pedja Janaćković (the corresponding author of the current study), following the professional literature [31,32,33,34,35]. Local names were harmonized upon Simonović [36]. Each plant mentioned by the respondent was compared with a fresh specimen or with illustrations and photographs from referent literature sources to avoid errors related to the existence of different local names and misleading plant descriptions. The nomenclature of the species was compiled from contemporary checklists, monographs and databases, such as EURO + MED (Plantbase, http://ww2.bgbm.org/EuroPlusMed). Voucher specimens were deposited in the Herbarium of the University of Belgrade—Faculty of Biology, Institute of Botany and Botanical Garden “Jevremovac” (BEOU) (Table 1). Standard herbarium acronym follows Thiers B., 2019 + : Index herbariorum (http://sweetgum.nybg.org/science/ih/) [37].

Table 1 Recorded plant species in Aleksinac and Bor districts of eastern Serbia, their scientific names, affiliation to family, voucher numbers and vernacular names

No explicit rules or regulations pertain to the practice of ethnobotanical research in Serbia. The purpose, methodology and nature of the research were explained before starting the interviews and oral informed consent was obtained from all informants. Each participant in the study agreed to participate voluntarily. Participants were allowed to discontinue the interviews at any time. Upon completion of the study, all data are deposited in the phonothèque of the Department of Morphology and Systematics of Plants, University of Belgrade—Faculty of Biology. Thus, the ethnobotanical research and related activities, including collecting of plants, compiling databases, images, audio recordings, gathering information on the uses of traditional knowledge or other elements of biocultural heritage found in the study area, were undertaken in compliance with the International Society of Ethnobiology (ISE) code of ethics [38]. No harmful consequences (biological or cultural) for the local people and local communities arose from this research and its related activities. During the research, all principles of the code of ethics were adhered to including intellectual property rights and support for the development of local people’s cultures. All recommended standards for conducting and reporting ethnobotanical studies were considered in accordance with Weckerle and colleagues (2018) [39].

Data analysis

Frequency of citation (FC) and relative frequency of citation (RFC).

The FC was calculated as follows:

FC = (Number of times a particular species was mentioned)/(total number of times that all species were mentioned) × 100.

The RFC index [40] was evaluated by dividing the number of informants who mentioned the use of the species (FC) by the total number of informants participating in the survey (N). The RFC index ranges from “0” when nobody refers to a plant as useful to “1” when all informants refer to a plant as useful. RFC = FC/N.

Relative importance index (RI)

According to Tardío and Pardo-De-Santayana (2008) [40], this index was calculated with the following equation:

$${\text{RIs }} = \, \left\{ {{\text{RFCs}}\left( {{\text{max}}} \right) \, + {\text{ RNUs}}\left( {{\text{max}}} \right)} \right\}/{2}$$

where RFCs(max) is the relative frequency of citation over the maximum, i.e., it is obtained by dividing FCs by the maximum value in all species of the survey {RFCs(max) = FCs/max(FC)}, and RNUs(max) is the relative number of use-categories over the maximum, obtained by dividing the number of uses of the species by the maximum value in all species of the survey {RNUs(max) = NUs/max(NU)}. The RI index theoretically varies from 0, when nobody mentioned any use of the plant, to 1, when the plant was most frequently mentioned as useful in the maximum number of use-categories.

Informant consensus factor (ICF-FIC)

To test the homogeneity of knowledge, the informant consensus factor was used [41], as follows:

$${\text{ICF}} = \frac{{{\text{nur}} - {\text{nt}}}}{{{\text{nur}} - 1}}$$

where nur refers to the number of use-reports for a particular use category and nt refers to the number of taxa used for a particular use category by all informants. ICF values are low (near 0) if plants are chosen randomly or if there is no exchange of information about their use among informants, and approach one (1) when there is a well-defined selection criterion in the community and/or if the information is exchanged between informants [42].

Use value (UV)

Using the results obtained in the general interview, the use value (UV) of the plant species was calculated following [43,44,45] methods with some modification, using the following formula:

$${\text{UV }} = \Sigma {\text{U}}/{\text{n}},$$

where UV = use value of a species, U = number of quotations per species, and n = number of informants.

The use values are aggregated per plant part usage (counted as one in a certain category (a medicinal use, human nutrition, domestic animal nutrition, veterinary medicine, beliefs and contemplation and other purposes) regardless of different effects or uses. In other words, we did not aggregate statements for specific plant species per category, due to the nature of raw data from our study. We modified the earlier methodology in this way: if the same person cited the same plant but a different plant part or type of preparation in a certain category we mentioned that as a separate statement, because in this way a better insight into the importance of the use value of plants is gained.

The use value for each species can be calculated as the ratio of the number of citations to the total number of respondents.

where “U” refers to the number of uses mentioned by the informants for a given species and “n” refers to the total number of informants interviewed.

If a plant secures a high UV score that indicates there are many use-reports for that plant, while a low score indicates fewer use-reports cited by the informants.

Fidelity level (FL)

The percentage of informants claiming the use of a plant species for the same major purpose was estimated using the Fidelity level index as determined by the following formula:

$${\text{FL}} = \frac{{{\text{lp}}}}{{{\text{lu}}}}\;{\text{x 1}}00$$

where lp denotes the number of informants who indicate the use of a species for the same major ailment and lu refers to the total number of informants who mentioned the same plant for any other use [46]. High FLs are obtained for plants which are used in the same way according to the majority of informants. Only species with the lp greater than or equal to 5 and FL greater than or equal to 0.2 were considered.

Principal coordinate analysis (PCoA)

The principal coordinate analysis (PCoA) was used to test the relationships between objects (plants) and their uses, i.e. health-related disorder or medical.

To conduct PCoA, the dataset was systematized using the presence–absence matrix (1 and 0) with objects (plant taxa) in rows and categorical variable (health disorder/condition) in columns. As a result, the matrix 99 × 15 (number of species x number of illness) was obtained. This matrix is used to compute the similarity matrix based on Sokal and Sneath association coefficient (2) [47]:

$${\text{d}}_{{{\text{ij}}}} = \frac{2a + 2d}{{2a + b + c + 2d}},$$

where d_ij is the similarity between species i and j, a is the number of variables where x_i = presence and x_j = presence, b is the number of variables where x_i = absence and x_j = presence, c is the number of variables where x_i = presence and x_j = absence and d is the number of variables where x_i = absence and x_j = absence (Table 2).

Table 2 Frequency of four possible combinations for two binary variables

The similarity is 1 if two species share all 15 descriptors and similarity is 0 if two species do not share any descriptor. Based on the similarity matrix, PCoA is conducted.

All the above-mentioned analyses were performed using XLSTAT 2014 software (Addinsoft, NY, USA).

Jaccard index (JI)

This index is used to compare the present study data with the data of other ethnobotanical studies conducted in neighboring and other regions in Serbia. The formula used to evaluate the JI index [48] is as follows:

$${\text{JI}} = {\text{cx1}}00/{\text{a}} + {\text{b}} - {\text{c}},$$

where “a” is the recorded number of species of the study area “A,” “b” is the documented number of species of the area “B” and “c” is the common number of species in both area “A” and “B.” In the case of local communities, “a” is the number of species reported by a local community “A,” “b” is the number of species cited by the local community “B” and c is the number of species reported by both “A” and “B.”

Results and discussion

Demography of informants

A total of 155 informants were interviewed. Out of these, 42 (27.1%) were male and 113 (72.9%) were female. The informants were categorized into five different age groups, as documented in Table 3.

Table 3 Demographic characteristics of informants

Mode of preparation

The most frequently used mode of preparation was as an infusion (50.0%) followed by processed (12.9%), fresh (direct utilization) (10.1%), tincture (4.7%), balm (4.4%) and so on (Tables 4, 5 and 6 and Additional file 1: Table 1), which was also reported by ethnobotanical studies performed in the closest neighborhood regions [13, 15, 18]. The most used plant part (Additional file 1: Table 2) was the leaf (44.7%).

Table 4 Medical uses of plant species of the Aleksinac and Bor districts of eastern Serbia

Table 5 Human and domestic animal nutrition and veterinary medicine use of plant species of the Aleksinac and Bor districts

Table 6 Folk and religious rituals and ethnoculture, and other purposes of plant species of the Aleksinac and Bor districts

Quantitative ethnobotanical analysis

The results of the study (Tables 4, 5 and 6) provide information on the use of 114 wild and few domesticated (but still wild growing) plant species quoted by respondents from East Serbia. Recorded plants belong to 97 genera and 47 families, of which the Asteraceae (14.0%), Rosaceae (13.2%), Lamiaceae (7.9%) and Fabaceae (7.9%) were the most represented, similarly to other ethnobotanical studies conducted in Serbia and the Balkans [12, 17, 21].

Use-reports

Out of the total of 2333 reports on the use of plants obtained by respondents, 1653 reports were given for medical purposes, 496 for human nutrition, 26 for animal nutrition, 38 for veterinary purposes, 57 for folk and religious rituals and ethnoculture and 63 for other purposes. Out of a total of 155 informants, 113 women gave 1834 use-reports, while 42 men gave 499. There were no differences between statements provided by men and women with exception for notes on the herbal micellar water and herbal medicinal syrup which were stated specifically by women. There were no differences between men and women regarding the curative and prophylactic use of plants for certain illnesses and disorders. In regard to traditional knowledge on the use of the wild plants for nutrition, religious and other traditional customs and for other purposes, both genders gave more–less similar information. Statements related to ethnoveterinary purposes are more frequently given by men than women.

Out of 2333 use-reports, 1180 (50.6%) were provided by inhabitants from the cities, while 1153 (49.4%) were provided by village inhabitants. There were no statistically significant differences between data on the traditional use of plants between inhabitants from cities and from villages concerning plant part in use and disorders treated by herbs. This is mainly due to the fact that inhabitants of these small semi-urban areas are usually tightly stuck to surrounding rural places, still performing some farming or horticulture for their own needs. However, there were some differences related to the traditional use of plants. Much more statements on animal nutrition, veterinary purposes, folk and religious rituals and ethnoculture, as well as for some less frequent uses, were obtained from inhabitants settled in the villages. Utilization of plant species for certain handicraft uses, as well as the note on common chicory (Cichorium intybus L.) as a coffee substitute, was mentioned only by respondents settled in the villages.

Frequency of citation (FC), relative frequency of citation (RFC) and relative importance index (RI)

In the present study, FC values ranged from 0.05 to 13.1 (Additional file 1: Tables 3 and 4). The highest FC values are recorded for Hypericum perforatum (13.1), followed by Urtica dioica (9.0) and Plantago major (5.1). RFC values ranged from 0.001 to 0.2 (Additional file 1: Tables 3 and 4). The highest RFC was recorded for Hypericum perforatum (0.2) and Urtica dioica (0.2) followed by Plantago major (0.1). As can be seen, the ethnomedicinal plants having high RFC values indicated their abundant use and widespread knowledge among the local communities. RI values ranged from 0.1 to 1 (Additional file 1: Tables 3 and 4). The highest RI values were calculated for Urtica dioica (1.0), followed by Hypericum perforatum (0.7) and Rosa canina (0.7).

All these plants are among the most frequently reported in several neighboring regions, i.e., studied sites from southeast and south Serbia and from Kosovo [12, 17,18,19, 21].

Informant consensus factor

The documented uses of plants in folk medicine refer to the treatment of 15 different groups of disorders. The ICF values ranged from 0.0 to 100.0% and 36.4% to 88.5% for Aleksinac and Bor districts, respectively. The highest ICF value found for the Aleksinac district was related to endocrine system disorders followed by skin-related disorders (79.7%) and circulatory system disorders (69.4%), while the lowest ICF value was found for antiseptic activity and metabolic disorders (0.0%). On the other hand, the highest ICF value for the Bor district was determined for skin disorders (88.5%), followed by digestive system disorders (83.5%) and respiratory system disorders (81.4%), while the lowest ICF value was 36.4% for antiseptic activity (Additional file 1: Table 5). A large number of species described by respondents of Bor district are used for the prevention and healing of digestive and respiratory system disorders. Such a fact might be related to very expressed air and soil pollution, as a consequence of mining and severe dust emission [49]. For the two studied regions considered together, the ICF values ranged from 33.3% to 88.9%. The highest ICF value was determined for skin disorders, followed by respiratory system disorders (82.1%) and digestive system disorders (82.1%), while the lowest ICF value was found for reproductive system disorders (51.4%) and antiseptic activity (33.3%) (Additional file 1: Table 6).

The ICF values ranged from 0.0% to 100.0% and 0.0% to 100.0% for men and women in the Aleksinac district, respectively. The highest ICF value found for men was related to endocrine system disorders followed by skin-related disorders (71.4%) and circulatory system disorders (50.0%), while the lowest was found for metabolic disorders, musculoskeletal system disorders, sensory system disorders, tumor ailments and urinary system disorders (0.0%). On the other hand, the highest ICF value for women was determined for endocrine system disorders and tumor ailments, followed by skin-related disorders (78.4%), while the lowest was recorded for musculoskeletal and sensory system disorders (0.0%) (Additional file 1: Table 7). When it comes to Bor district, the ICF values ranged from 0.0 to 85.7% and 30.0% to 86.9% for men and women, respectively. The highest ICF value found for men was related to sensory system disorders followed by skin (77.8%) and immune system disorders (63.0%), while the lowest was recorded for metabolic disorders (0.0%). On the other hand, the highest ICF value for women was determined for skin system disorders and digestive system disorders (82.8%) followed by immune system disorders (81.5%), while the lowest was recorded for antiseptic activity (Additional file 1: Table 8). In both districts together, the ICF values ranged from 0.0 to 100.0% and 27.3 to 88.0% for men and women, respectively. The highest ICF value found for men was related to endocrine system disorders followed by skin system disorders (79.6%) and immune system disorders (69.4%), while the lowest was recorded for metabolic disorders (0.0%). On the other hand, the highest ICF value for women was determined for skin-related disorders, followed by immune system disorders (82.8%) and respiratory system disorders (80.1%), while the lowest was recorded for antiseptic activity (27.3%) (Additional file 1: Table 9).

Regarding differences recorded in the city and surrounding villages, it was shown that the ICF values ranged from 0.0 to 100.0% in Aleksinac district. The highest ICF value found for both, citizens from the town and citizens from surrounding villages, was related to endocrine system disorders followed by skin system disorders (66.7% and 80.4%, respectively), while the lowest was recorded for musculoskeletal, reproductive, respiratory, sensory, urinary system disorders and musculoskeletal system disorders, respectively (Additional file 1: Table 10). When it comes to Bor district the ICF values ranged from 29.2 to 80.0% and 0.0 to 87.5% for citizens from the town and citizens from surrounding villages, respectively. The highest ICF value found for citizens from town was related to skin system disorders followed by digestive system disorders (74.4%), while the lowest was recorded for general health (29.2%). On the other hand, the highest ICF value for citizens from surrounding villages was determined for sensory system disorders, followed by skin (82.4%) and respiratory system disorders (77.3%), while the lowest was recorded for metabolic disorders (0.0%) (Additional file 1: Table 11). In both districts, the ICF values ranged from 28.0 to 82.5% and 0.0 to 100.0% for citizens from the town and citizens from surrounding villages, respectively. The highest ICF value found for citizens from town was related to skin system disorders followed by digestive (75.1%) and respiratory system disorders (74.8%), while the lowest was recorded for general health (28.0%). On the other hand, the highest ICF value for citizens from surrounding villages was determined for endocrine system disorders followed by skin (86.8%) and immune system disorders (79.2%), while the lowest was recorded for antiseptic activity (0.0%) (Additional file 1: Table 12).

Use value (UV)

In the present study, the UV (Additional file 1: Table 13) in Aleksinac district ranged between 0.02 and 0.8. Based on UV data, the five most commonly used ethnomedicinal plant species were Hypericum perforatum (0.8), Urtica dioica (0.6), Plantago major (0.3), Sambucus nigra (0.3) and Achillea millefolium (0.3). The UV (Additional file 1: Table 14) in Bor district ranged between 0.01 and 1.4. The five most commonly used ethnomedicinal plant species in Bor district were Urtica dioica (1.4), Hypericum perforatum (1.3), Sambucus nigra (1.1), Rosa canina (0.9) and Rubus plicatus (0.7). These species were used for diverse purposes which are indicated in Tables 4, 5 and 6.

Fidelity level

Fidelity level (FL) value in Aleksinac district ranged from 21 to 100%. The highest FL of 100% was recorded for Allium ursinum and Crataegus monogyna (circulatory system disorders), Althaea officinalis and Hedera helix (respiratory system disorders) and Betula pendula (urinary system disorders) (Additional file 1: Table 15). Further results showed that FL value in Bor district ranged from 22 to 100%. The highest FL of 100% was recorded for Alchemilla vulgaris (reproductive system disorders), Melilotus albus (circulatory system disorders) and Rumex patientia (digestive system disorders) (Additional file 1: Table 16). In addition, the results for the entire studied area showed that FL values range from 25 to 100%. The highest FL of 100% was recorded for Alchemilla vulgaris (reproductive system disorders), Crataegus monogyna and Melilotus albus (circulatory system disorders) and Rumex patientia (digestive system disorders) (Additional file 1: Table 17). FL values indicate that respondents from Aleksinac district mostly use plants for skin system disorders (five species), while respondents from Bor district mostly use plants typical for the treatment of digestive system disorders (13 species).

Based on use-records given by men and women, FL values, in Aleksinac district, ranged from 75 to 100% and 33.3 to 100.0%, respectively. The highest FL of 100% according to men uses was recorded for Juglans regia (endocrine system disorders) (Additional file 1: Table 18), while for women was recorded for Betula pendula (urinary system disorders), Crataegus monogyna (circulatory system disorders) and Hedera helix (respiratory system disorders) (Additional file 1: Table 19). On the other hand, FL values in Bor district ranged from 30.8 to 88.9% (based on man uses) and 20.0 to 100.0% (based on women uses). The highest FL according to men uses was recorded for Melissa officinalis (nervous system disorders) (Additional file 1: Table 20), while for women was recorded for Alchemilla vulgaris (reproductive system disorders), Epilobium parviflorum (urinary system disorders), Euphrasia officinalis (sensory system disorders), Melilotus albus (circulatory system disorders) and Mentha longifolia and Rumex patientia (digestive system disorders) (Additional file 1: Table 21). In addition, the results for the entire studied area showed that FL value ranged from 27.8% to 100% (man uses) and 20.0% to 100% (women uses). The highest FL based on men use-records was recorded for Juglans regia (endocrine system disorders), Pulmonaria officinalis (respiratory system disorders) and Sambucus nigra (immune system disorders) (Additional file 1: Table 22). The highest FL based on women use-records was recorded for Alchemilla vulgaris (reproductive system disorders), Betula pendula and Epilobium parviflorum (urinary system disorders), Crataegus monogyna and Melilotus albus (circulatory system disorders), Euphrasia officinalis (sensory system disorders) and Mentha longifolia and Rumex patientia (digestive system disorders) (Additional file 1: Table 23). FL values indicate that men from Aleksinac district mostly use plants for skin system disorders (two species), while men from Bor district mostly use plants typical for the treatment of digestive system disorders (five species). FL values indicate that women from Aleksinac district mostly use plants for skin system disorders (five species), while women from Bor district mostly use plants typical for the treatment of digestive system disorders (12 species).

In addition, based on use-records given by citizens from the town and citizens from surrounding villages FL values in Aleksinac district ranged from 55.6 to 100% and 42.9 to 100.0%, respectively. The highest FL (citizens from town) was recorded for Paliurus spina-christi (digestive system disorders) (Additional file 1: Table 24), while the highest FL (citizens from surrounding villages) was recorded for Althaea officinalis (respiratory system disorders), Betula pendula (urinary system disorders), Crataegus monogyna (circulatory system disorders), Hedera helix and Pinus nigra (respiratory system disorders) (Additional file 1: Table 25). On the other hand, FL values in Bor district ranged from 50.0% to 100.0% (citizens from town) and 18.2 to 100.0% (citizens from surrounding villages). The highest FL (citizens from town) was recorded for Cichorium intybus (digestive system disorders) and Sambucus nigra (respiratory system disorders) (Additional file 1: Table 26), while the highest FL (citizens from surrounding villages) was recorded for Alchemilla vulgaris (reproductive system disorders), Epilobium parviflorum (urinary system disorders), Euphrasia officinalis (sensory system disorders), Humulus lupulus (nervous system disorders), Melilotus albus (circulatory system disorders) and Mentha longifolia and Rumex patientia (digestive system disorders) (Additional file 1: Table 27). In addition, the results for the entire studied area showed that FL values ranged from 23.1% to 100% (citizens from town) and 25.0% to 100% (citizens from surrounding villages). The highest FL (citizens from town) was recorded for Alchemilla vulgaris (reproductive system disorders), Euphrasia officinalis (sensory system disorders), Melilotus albus (circulatory system disorders), Paliurus spina-christi and Rumex patientia (digestive system disorders) and Valeriana officinalis (nervous system disorders) (Additional file 1: Table 28), while the highest FL (citizens from surrounding villages) was recorded for Althaea officinalis (respiratory system disorders), Betula pendula (urinary system disorders), Crataegus monogyna (circulatory system disorders), Pinus nigra and Pulmonaria officinalis (respiratory system disorders) and Rumex patientia (digestive system disorders) (Additional file 1: Supplementary Table 29).

FL values indicate that citizens from Aleksinac town mostly use plants for skin system disorders (two species), while citizens from Bor town mostly use plants typical for the treatment of immune system disorders (three species). FL values indicate that citizens from surrounding villages in Aleksinac district mostly use plants for skin system disorders (four species) and respiratory system disorders (four species), while citizens from surrounding villages in Bor district mostly use plants typical for the treatment of digestive system disorders (14 species).

Obtained results point to the fact that although citizens from these districts rely on the official health care system, still medicinal plants have significant value in everyday life for these people.

Multivariate analysis

A scatter plot from principal coordinate analysis (PCoA) showed the formation of three distinct homogeneous groups (Fig. 1). The first group consisted of seven species (Rumex acetosa, Xanthium spinosum, Sambucus ebulus, Rumex patientia, Potentilla reptans, Paliurus spina-christi and Cydonia oblonga). All these species are grouped in relation to one variable, i.e., the effects on digestive system disorders. The second group was formed from five species (Melilotus albus, Loranthus europaeus, Allium ursinum, Crataegus monogyna and Viola odorata) acting mainly for circulatory system disorders, according to information from respondents. The third group consisted of five species (Petasites albus, Asparagus officinalis, Equisetum telmateia, Hieracium pilosella and Pyrus pyraster) which were mentioned for urinary system disorders application.

Fig. 1

Principal coordinate analysis of plants used in traditional human medicine in surveyed area in East Serbia

Traditional preparations and remedies

Out of 114 reported species, 101 (88.6%) are used for medical purposes (Table 4). Plants are the most commonly used to treat digestive system disorders (49.1%), circulatory system disorders (41.2%) and respiratory system disorders (35.1%). These findings on a wide use of plants for digestive and respiratory system conditions are in accordance with other ethnobotanical studies in Serbia [17, 18, 21]. Concerning plants used for medicinal purposes, 33 species are included in the European Pharmacopoeia 8.0. [50] (marked with ♦  in Table 4). Plant parts, i.e., plant drugs which differ from citations provided in European Pharmacopoeia 8.0. [50], are marked with hash (#) Table 4. Some interesting traditional remedies were recorded, which haven’t been so far indicated in previous ethnopharmacological studies in the Balkans.

H. perforatum is reported as an herbal remedy effective against every disorder (medical panacea) which is in agreement with some earlier investigation. Although spatially distant, in the Arribes del Duero (Spain), the cultural importance of H. perforatum oil is unquestionable. It is also cited, literally translated, that “What Hypericum doesn’t cure the doctor certainly won’t” [51]. Many previous studies on the Balkans documented its usage against diseases of different organ systems [52,53,54,55].

It is claimed that the best herbal medicines, with the most healing properties, are made if this plant is collected on July 7 (St. John’s Day). It is even stated that flowers smell different on that day. Flowers are collected, basted with sunflower or olive oil, and left in the sunlight for 40 days. On the 40th day, oil extract is brought into the home. Similar methods for preparation are noted in earlier studies both on Serbian territory [12] and in the region [21, 56,57,58]. Oil extract is used externally for skin ailments, hemorrhoids and gynecological problems. Živković and colleagues (2020) reported the same type of preparation against skin complaints and hemorrhoids [19], while Varga and collaborators (2019) reported the usage of infusion against gynecological diseases [59]. Internally, it is applied for digestive ailments and improving general health conditions.

Informants are also knowledgeable on the toxicity of certain medicinal plants, as well as their side effects when combined with medicinal drugs. For example, they stated that H. perforatum tea should not be used together with drugs used in the treatment of malignant diseases because it can “completely reverse the effect of the drug.” Also, tea should not be drunk for more than seven days in a row.

When it comes to medicinal herbs, the so-called Ciklus svetojovanskog bilja (lit. Cycle of St. John’s herbs) is also mentioned. It encompasses the period from June 28 (Vidovdan; lit. St. Vitus day) to July 7 (Ivanjdan; St. John’s Day) when it is most desirable to collect certain medicinal herbs (Achillea millefolium, Melissa officinalis and Hypericum perforatum).

It is not unusual for some traditional receipts in Serbia to be prepared during the 40 days. It is possible that roots of the method of preparation lie down in the Christian religion where the number 40 has a particular meaning. Christians believe souls need 40 days after death to leave the Earth, in the Bible it is mentioned that the great flood lasted 40 days and nights [60], Moses spent 40 days and nights in Mount Sinai, the same number of days Jesus fasted and was tempted in the wilderness [61]. We assume that it is easier for people to remember and pass on the knowledge related to the preparation if there is some universally known fact.

Traditional tinctures

Homemade tinctures are usually prepared with the fruit spirit (`rakija` in Serbian). Among the most used, there are the tinctures made of a single herb, such as wild thyme, nettle or marigold, or those prepared of mixture herbs.

Tincture for a massage, circulation improvement and thrombosis prevention is made of hundreds of marigold flowers (Calendula officinalis) put in a liter of “rakija”. The usage of this herb as a tincture also was noted in the research conducted in southwestern Serbia [14]. The comfrey (Symphytum officinale) tincture is made in a similar way (one mature root is put in one liter of rakija), or the drug is mixed with five wild chestnut fruits and one rosemary branch in half a liter of spirit for healing of leg pains and varicose veins. One ethnobotanical investigation previously published, conducted in the northeastern part of Croatia, reported the traditional use of comfrey’s roots as tincture against cardiovascular disorders [62].

Syrups and honey

Few informants mentioned preparation of homemade syrup for strengthening immunity, which was especially recommended to children. The syrup is made from Pinus nigra shoots, Plantago lanceolata leaves, Sambucus nigra flowers, Thymus serpyllum aerial parts and Tussilago farfara leaves. The preparation is made by boiling of sugar (3 kg) for 10 min and thereafter adding 300 g of each plant drug to cook for an additional 9 min exactly. In the final step, 15 g of commercial citric acid is added, and the mixture is cooked for one more minute.

Nettle (Urtica dioica) syrup is considered as the best medicine for strengthening the immune system in patients with anemia. Firstly, red wine is cooked with yellow sugar. When it comes to boiling, 50 young apical parts of nettle are added, and it is cooked for 2–3 min. Every morning before breakfast, a small glass of preparation should be consumed.

To the best of our knowledge, these receipts are mentioned for the first time on the Balkan Peninsula.

The honey is often mixed with herbs for different treatments. For example, there is a recipe quoting that two tablespoons of the black pine (Pinus nigra) pollen, locally known as “flower powder” (in Serbian, “cvetni prah”) are mixed with 200–300 g of meadow honey. It is believed that this remedy improves respiratory ailments. These results are similar to those obtained from the Kopaonik mountain where buds and needles of P. sylvestris are also mixed with honey in the final part of the preparation of medicine against chronic bronchitis [12] Mustafa and colleagues (2012b, 2020) reported mixing cones of Pinus spp. with honey to treat respiratory system ailments, which is partially in agreement with the results of the current study [56, 63]. The arum is also mixed with honey: one kilogram of Arum maculatum rhizome is combined with a kilogram of honey. The mixture is consumed 2–3 times a day before a meal for digestion and hemorrhoids treatment. A particular product is made of dandelion flowers (Taraxacum officinale). It is called “dandelion honey.” Dandelion flowers are collected and cooked together with water and sugar until the flowers are completely cooked in the mixture. This product is frequently prepared and consumed in the Balkans, according to some previous ethnobotanical studies [56, 64].

Ointment for skin diseases

Ointment is prepared with a hundred of marigold petals fried with a tablespoon of homemade grease and it is used cold for the treatment of urticaria. Our results are congruent with some previous studies [16], which mentioned the similar use of these flowers against different skin injuries [12,13,14, 19]. Twigs of elder (Sambucus nigra) are used for preparing balm for burns therapy and insect and spider bites treatment. Twigs are grated and mixed with plant wax, honey, the incense and chopped yarrow (Achillea millefolium) leaves. The mixture is filtered and stored in a cold place.

Decoction for urinary diseases

Aerial parts of Equisetum telmateia are mixed with young corn cobs and corn silk (elongated stigmas) and cooked in water. The mixture is cooked until the volume of water drops to a third of the initial volume, and the color becomes red. The decoction is used against urinary problems.

Wild herbs for human nutrition

There were 37 (32.5%) plant species recorded for human nutrition (Table 5). Out of 37 species used for nourishment, 35 species are simultaneously used for medical treatments. The plant drugs are used fresh, dry and processed. Homemade food and beverage products made from or with the addition of wild plants include juices, jams, compotes, wine and Serbian traditional sweet dish “slatko” [65]. Fresh and dried herbs are often used for seasoning, i.e., as spices, either single or in mixtures (e.g., Achillea millefolium, Allium ursinum, Melissa officinalis, Origanum vulgare, Satureja subspicata, Thymus serpyllum, and Urtica dioica). Salad used for nutrition, additionally providing health benefits, especially for stomach ailments regulation is prepared as a mixture of leaves of five species: Fragaria vesca, Plantago major, Rubus plicatus, Rumex acetosa and Urtica dioica.

For the preparation of the sweet delicacy “slatko” the petals of the dog rose (Rosa canina) are used. Firstly, the petals are mixed with water and sugar and the mixture is boiled for at least half an hour. In the next step, a few drops of lemon juice are added to restore a petal color (should remain as gently reddish).

Traditional and beloved herbal beverages in Balkans mainly refer to those made of elder flowers, which has been already reported in some former studies [16]. The new information obtained in our research is related to the note about potential negative effects on men's fertility if it is overused. Elder fruits are used either fresh or processed, mostly for preparing a fruit wine. Fruits of elder are cooked for 15 min at 80 °C with water and sugar (half of the quantity of used fruits), and left for fermentation. Similar use of elder is already known in Europe [66].

Replacement for traditional coffee drink is made of dried and grinded chicory (Cichorium intybus) roots mixed with Turkey oak (Quercus cerris) acorn for nicer flavor.

Overlap of medicinal and food plants

In our study, nearly 100% plant species overlap as food and medicine. This finding is in agreement with another study conducted in Negotin, the very near region [17]. In that study, all plants mentioned as food plants are also used in herbal medicine. An identical situation is observed in the southeastern Serbia (Suva Planina) [16]. On the contrary, on the Kopaonik Mountain (Central Serbia), out of 24 plant species mentioned for nutrition, slightly more than a half are used for both nutrition and medicine [12]. However, in the neighboring country (Croatia) results are different. In a study conducted in Dalmatia, 41 plant taxa are mentioned to be used exclusively for treating a variety of ailments, 43 exclusively as food and 42 for both purposes [59]. Also, in Istria, out of 121 species, 31 species are used exclusively as food, 50 as medicine, and 40 species overlap [67]. On the other hand, a study conducted in the areas of the towns of Našice and Djakovo showed that 37 species are used exclusively as medicine, and 7 species overlap, but there are no plants that are used only as food [62].

Veterinary medicine

The 14 of 114 recorded plant taxa (12.3%) are used in veterinary medicine (Table 5). Plants are mostly used fresh, especially as revetment, and as extracts in form of infusion or decoction. A certain similarity in species used in human and veterinary folk medicine was noticed: of 14 species used in veterinary medicine, only two—the Helleborus odorus and Rumex crispus—are not used in humans.

Traditional practices for the treatment of domestic animals are preserved mostly in rural areas. The hellebore was indicated as an herbal remedy efficient in terminal illness in livestock and pigs. It is known that such practices were often used in the past, especially for horses [68]. Technique that relies on the usage of hellebore roots for this purpose is called in Serbian “natravuvanje stoke” (there is no suitable translation for the term specified). The cleansed fresh or dried part of the root is directly inserted in a certain part of the animal body: into the ears in the case of pigs or in loose skin below the neck in the case of cows. The function of drying is to prevent root bending for easier insertion. Ear of the sick pig is pierced by an awl and a cleansed root is inserted. The root is not removed until the surrounding area becomes purulent and swollen. Part of the ear falls off but a life-threatened animal survives. When cows are treated, a cleansed root is inserted in a dewlap and the tip of the root is left to jut. Root is left in a loose skin on the neck for 24 h. After the defined period has elapsed, root is removed and accumulated pus leaks out. The method is not approved by veterinarians today. However, the informants asserted that sometimes it is necessary—as an extreme way to save the sick animal. The utilization of hellebore for ethnoveterinary purposes is known from earlier ethnobotanical studies conducted in Serbia [12, 13, 17], but details are for the first time provided here.

Mastitis in cattle is caused by various factors, mainly infections, but also by some other physical and chemical traumas [69]. Two plant species are mentioned for mastitis treatment, the agrimony (Agrimonia eupatoria) and the vervain. Ethnoveterinarian study from Italy provides information on the usage of vervain against mastitis in cows although the methods of application differ [70].

Folk and religious rituals and ethnoculture

The usage of a total of 17 (14.9%) plant species is linked to traditional customs and rites (Table 6). Many plant species are utilized for religious purposes and various stories and legends are related to their role in ethnoculture. There were some differences in the use of herbs in traditional customs between two investigated districts. Performing rituals for the Fest Days is more developed and practiced in the Bor District. Most of the respondents stressed that wild plants are gladly used in celebration of some holy and festive days, especially the St. George’s Day (“Đurđevdan” in Serbian; May 6) and the St. John’s Day (“Ivanjdan” in Serbian; July 7). In Bor district, more data were obtained on folk customs and tradition, possibly because of the need to protect the national identity in a multicultural community. In the Bor District, four plant species are used for St. George’s Day celebration. Early in the morning, H. odorus aerial parts are tied and left to hang in the part of the yard where cattle reside as protection against spells and impure forces. On the Eve of St. George’s Day, geranium (Geranium macrorrhizum) flowers and leaves and willow (Salix alba) twigs with leaves are combined to make garlands. Garlands are placed around buckets used for sheep milk collection to increase milk yield. The willow is also placed around the waist to avoid back pain throughout the year. Hazelnut (Corylus colurna) is also used for this Fest Day. It is also used in rural areas as a defense against snakes. Hazelnut is put on the fence around the house, especially in front of the front door because it is believed that snakes do not approach this area. Also, informants carry sticks made of hazelnut branches in the wild to protect them against snakes. Hazelnut fruit is an amulet. Usage of these species has been confirmed and found in the literature. It is also known that other species of the genera Corylus are used in the same way as mentioned hazelnut [68].

For Easter, local people make a mixture of Cornus mas flowers and Urtica dioica leaves. Red wine and an Easter egg (exclusively red color) with bread crumbs are added to the mixture. Early in the morning, in front of the front door, family members cross themself, turn in the direction of sunrise three times and after every turn, they drink a teaspoon of this beverage. The order is from the oldest to the youngest member of the family.

Garlands are made for St. John’s Day too. Different plant species are included but the most abundant one is yellow bedstraw (Galium verum). Other plant species that can be inserted are A. millefolium, H. perforatum, Tanacetum vulgare. Garlands are hung on the front door of home and kept until the next year on the same day. On that day, last year’s garlands are thrown away and the new ones are made. Custom is repeated every year. It is believed that this custom secures home protection from negative influence, evil thoughts and glances. It is shown that yellow bedstraw is a favorite flower among people and that this custom is used a lot. There is also evidence that garlic can be inserted into the garlands [68]. Tea made of H. perforatum is drunk as a part of religious beliefs. This plant is considered as one with an extremely magical effect for evil spirits expelling. Because of that, it is consumed only in the evening. The magical power of H. perforatum was also confirmed in the literature [71].

In the Aleksinac, customs for St. George’s Day are also performed. The customs differ from the ones in the Bor District. One of the symbolic acts for celebration is home gate decorating. Plant species used are Cornus mas, Salix purpurea and Helleborus odorus. Earlier, children were bathed with these plants and red eggs that have been kept since Easter to ensure their health. Young couples were collecting aerial parts of Galium aparine and binding themself around the waist because it is believed that done deed will secure their love forever. Beliefs related to uses of this plant are known from the literature. If the young woman takes part of the plant and inserts it into her left sock, she will be appealing to others and liked by them [68].

Oak (Quercus cerris) is used as a ritual tree. It is brought into the house and also left in front of the door on Christmas Eve.

People use Asarum europaeum in their diet as a spice and for religious purposes. It should be kept especially if there are small children. It is believed that they will not cry or be afraid in the presence of this plant. Occasionally, it is used to incense houses. Sempervivum tectorum is planted in the front of the house as a protection from evil forces.

Laserpitium siler is a species that is connected to various stories and beliefs, primarily “as a key for all locks,” the key to success, and as a protector of home and a person [8]. Thanks to such beliefs it is good to carry a part of this plant in a wallet or at home. Some informants mentioned that they have this plant in their car as a protection from accidents. Usually, root is used, but any other part of the plant can be used. Since the species is rare in nature, the broad-leaved laserwort (L. latifolium) is used as a replacement according to the results of the current study. Some informants mentioned that crumbled parts are burnt and used as smoked incense to protect home from spells and witchcraft. It is believed that hedgehogs can find the plant to protect their cubs. This story is characteristic of east Serbia [68].

According to respondents, the chicory is used as a guardian for travelers. It is believed that it always brings people back to the place where they came from. The plant is a good protector from diseases, accidents and other bad things.

Other uses

There are few plant species listed for face and body care use. Herbal cosmetic products varied in their complexity. There were simple products that include material from the single species, with a simple method of preparation (e.g., St. John’s Wort oil extract). Some informants indicated that asarabacca (Asarum europaeum) was applied in fragrant baths in the past. Squashed roots are left in a bowl of water and poured into a bath. Today, it is not practiced anymore due to the awareness of respondents on the toxicity of the plant.

Homecrafts are pretty rare in the study area, but there are still some rural households using plants in some practices. For example, Clematis vitalba branches are used for making simple beehives, and Melissa officinalis for gathering bees together due to its pleasant scent. The nettle was recorded as a pest repellent which is in accordance with data provided by Mullalija and collaborators (2021) [21].

Ethnobotanical richness and the similarities with other ethnobotanical investigations in Serbia (Jaccard index)

Results of this research were compared with data obtained from earlier studies conducted on the territory of Central Serbia [12], southwestern Serbia [13, 14], and especially of those performed in the closest areas, i.e., parts of the eastern and southeastern Serbia [15,16,17,18,19,20] (Table 7). According to the JI (Table 7), the highest degree of similarity was recorded with studies conducted on Suva Planina mountain (southeastern Serbia) with a JI of 28.7, Kopaonik (Central Serbia) with a JI of 27.3, as well as River Timok region and Mountain Svrljig region (eastern and southeastern Serbia) with a JI of 24.1. It was shown that small and isolated areas provide more specific information on the traditional uses of wild plants [72].

Table 7 Ethnobotanical comparison between our results and ethnobotanical data conducted in other investigated areas of Serbia

Novel ethnobotanical records

The results of our study highlighted the new usage of some well-known traditional plants in Serbia and Balkans. These plant species are: Robinia pseudoacacia, Sempervivum tectorum, Taraxacum officinale, Teucrium chamaedrys, Tilia platyphyllos, Urtica dioica, Verbena officinalis and Veronica officinalis. They are used for different purposes: four for medicinal uses (Sempervivum tectorum against headache; Taraxacum officinale for face washing, positive effect on vocal cord, against jaundice; Teucrium chamaedrys for eye ailments, cataract treatment; Veronica officinalis for blood vessels cleansing), one for veterinary use (Verbena officinalis against udder inflammation in cows), one for nutrition (Robinia pseudoacacia breaded as food) and two for other purposes (Tilia platyphyllos for egg dyeing; Urtica dioica for rubbing ear before piercing) (Tables 4, 5 and 6▲).

Interesting information was obtained for the field horsetail, the Equisetum arvense. Although the use of this plant in Serbia and in the Balkans is well known from before, the usage of fertile parts was not mentioned in any of the other ethnobotanical studies. Herbal remedies made from fertile parts are applied in the same way as the sterile parts. The interesting note was on people’s perception of the herb. Usage of the fertile parts was recorded in the village Jakovlje, where women call the plant “štukavac,” because it occurs around St. George’s Day, after which it disappears (Serb. local folk dialect “štukne “ in Eng. fade away) until the next spring. According to the respondent, the fertile part (the spike) of the field horsetail was in fact considered as a different species.

After comparison with studies conducted in Serbia, in addition to the review of available textbooks on medicinal plants, we assumed that 11 species were noted for the first time (marked with asterisk (*) in Tables 4, 5 and 6). Of these 11 species, the application of 4 species—Alcea biennis, Asplenium viride, Kickxia elatine and Xeranthemum cylindraceum, in the folk medicine is novel information for the Balkan region (according comprehensive review of the most relevant ethnobotanical and ethnopharmacological surveys performed in the Balkan region [52,-54,56,57,59,62,63,73–88].

In addition to use in some traditional handicrafts, the Xeranthemum cylindraceum (Fig. 2A) is also used for medicinal purposes. Brooms (aerial parts) are soaked with warm water and applied on the back against fever. There are several studies implying antipyretic activity of members of Asteraceae family [89,90,91]. The effect on health could also be attributed to the specialized metabolites of this species. The essential oil obtained from the aerial parts of the plant represents a terpenoid-rich mixture, with 1,8-cineole, α-terpineol, hexadecanoic acid and caryophyllene oxide as predominant compounds. The guaianolide-type sesquiterpene lactones xerantholide and 11,13-dihydroxerantholide were the major compounds found in the extracts, along with 3-hydroxybenzaldehyde. The sesquiterpene lactone of an eudesmanolide type 11,13-dihydroisoalantolactone and pseudoguaianolide confertin were present in extracts as well [92]. Sesquiterpene lactones, as well as essential oil compounds, exhibit an antipyretic activity [93, 94]. Therefore, the use in folk medicine as mentioned by respondents in our study sounds reasonable.

Fig. 2

Novel information for Balkan region regarding usage of four species in the folk medicine. A Xeranthemum cylindraceum Sm. (Photograph by Miletić, M.); B Asplenium viride Huds. (Photograph by Janaćković, P.); C Kickxia elatine (L.) Dumort (Public domain); D Alcea biennis Winterl (Photograph by Miletić, M.)

Asplenium viride (Fig. 2B) leaves are collected and prepared as an infusion. The purpose of the infusion administration is to cure fright. Potential medicinal properties of A. viride, as an antihypertensive drug, were noted in the research on cardiovascular diseases in the Iberian Peninsula and the Balearic Islands [95]. The phytochemical constituents of this plant species have not been sufficiently investigated. Plant with the same name in Serbian, the “strašnik” is Ceterach officinarum Willd. (syn. Asplenium ceterach L.). The etymology of the local name is linked to the “fear” (in Serbian “strah”), which could explain its use as an anxiolytic drug. C. officinarum is known from Serbian textbooks of medicinal plants [9, 96] and from ethnobotanical research [18].

According to our investigation, the Kickxia elatine (Fig. 2C) is used as a herbal remedy for wound healing, mainly for farmers being hurt during their work on the fields. In case of an injury, the plant is applied at the wounded place. There is a similarity in the use of the plant comparing our results with two studies conducted on spatially distant regions. Uses of Kickxia elatine are known from the Italian and Indian ethnobotanical studies. In Italy, it is directly applied to prevent and decrease the feet sweating [97]. The local tribes of the Western Ghats in India use this plant as a hemostatic agent and for wound treatments [98]. There are only a few studies focusing on the phytochemistry of this species. The main identified compounds are the iridoids, namely iridoid glycosides, kickxioside, antirrinoside, antirride, mussaenosidic acid, 5-O-menthiafoloylkickxioside and kickxin [99].

Alcea biennis (Fig. 2D) infusion is made of leaves. According to records obtained in our study, it is utilized for respiratory and digestive system disorders, i.e., for cough treatment, against sinusitis and against intestine diseases. The traditional uses of this species are recorded for Turkey and Iran [100,101,102]. There is much similarity in traditional use of the plant in folk medicine in our and these studies. To the best of our knowledge, Alcea biennis has not been studied from the phytochemical aspect.

Concluding remarks

Both qualitative and quantitative methods are quite valid in ethnobotanical studies. While qualitative data collection allows in-depth exploration of traditional knowledge regarding wild plants, quantitative methods can be useful in the comparison of the efficacy of different data collection methodologies [103]. Quantitative analyses represent a tool for obtaining data comparable to other studies as well as deriving reasonable conclusions based on the data collected. Increasing quantification of ethnobotanical studies has been continuously highlighted by some ethnobotanists [104, 105]. Some authors evaluated the use of Ellenberg values to establish whether there are differences between the environmental preferences of wild medicinal and food plants. Similar quantitative analysis would strengthen the discipline and provide rigorous testing methods [67]. However, some limitations of our work may refer to revealing the group of plants most important to a culture of this area, since we used the quantitative methods to measure individual traditional botanical knowledge, but on the other hand, this is important for comparison, in the future, with ethnobotanical heritage in similar small regions. Also, we performed a multivariate analysis with a clearly defined goal in the first place, to find a connection between plants and their usage, keeping in mind Pieroni's (2002) observation that, in some cases, it is easier to be impressed with this method, but without motivation for its usage in the right way.

High migration rates, depopulation and aging are typical features for rural Balkan areas causing accelerated loss of ethnobotanical knowledge and traditional practices in agriculture. Local inhabitants typically acquire ethnobotanical knowledge from their ancestors (parents, grandparents) and older neighbors in direct contact, which is a medium- and long-term risk for permanent knowledge loss. In addition, informants were concerned about the threatening of ethnobotanical information through its oral transmission and general weak interest of the young.

Some authors implemented a participatory approach in ethnobotanical research [106] where involvement and active participation of the local inhabitants should be included in the decision-making process and sustainable management of plant resources. The necessary actions for the preservation of both ethnobotanical knowledge and resources of medicinal plants in the studied area could be summarized as: a) raising of public awareness on ethnobotanical knowledge and related culture heritage, b) promotion of ethnotourism and traditional herbal remedies, food and beverage products, c) organization of herbal tours and d) creation of a sustainable management plan for economically important plants.

Our study indicated that small and specific areas in the Balkans (rural, abandoned, economically devastated and with high migration rate) may be an important reservoir of ethnobotanical knowledge, providing new information on the traditional use of plants. Results emphasized the great importance of wild plants in the daily life of the natives. Indigenous plants are still significant in traditional medicine. Therefore, there is a necessity to preserve the traditional knowledge of plant use, especially in regard to potential relevance for further pharmacological surveys. New records on use of the wild plants, as well as the way of their processing and combination in traditional remedies and products, confirmed our starting hypothesis on unique features of the study area.