Ethnobotanical research in Cava de’ Tirreni area, Southern Italy

The Cava de’ Tirreni area (Campania, Southern Italy, Fig. 1) is surrounded by two vast mountain ranges, in Northern and Southern directions, at a latitude of 40° and 40′ north and a longitude of 32° and 20′ East, (200 m a.s.l.). This area spread over 35 km², at the Northern borders of Salerno Province. We focused our research in this area because of its isolation and its economy, which is still partially based on small-scale agricultural and pastoral activities. We believe that this mountainous locality represents a potential interesting area for conducting studies on traditional ethnobotanical knowledge.

The area has a Mediterranean climate, with hot summers and wet winters. The coldest months are January and February with temperatures of 7.9 °C and 8.6 °C, while the hottest months are July and August with temperatures of 31.6 °C and 31.2 °C. The annual rainfall average is 1025 mm for 106 rainy annual days [5].

The area of Cava de’ Tirreni has been populated since ancient times, with a large part of its surface characterized by cultivations. Within cultivated species, the most important horticultural plants are belonging mainly to Solanaceae, Fabaceae, and Brassicaceae families and fruit plants belonging to Rosaceae. Morus spp., Ficus carica L., Punica granatum L., and Diospyros kaki Thunb. J. regia and Corylus avellana L. are also widespread, as well as Citrus limon (L.) Burm. f. Osbeck, Citrus aurantium var. dulcis L., and Citrus reticulata Blanco. Also, the cultivation of Vitis L., with different varieties, is diffused.

Besides cultivated fields, the area is also characterized by natural vegetation with a high level of biodiversity: this reflects both the presence of different substrates, such as limestone and thick soils of volcanic origin, and the presence of numerous microclimates, due to the fact that the area includes altitudinal bands ranging from 200 to 1000 m above sea level and exposed slopes in all directions [5].

The natural vegetation comprises a mosaic of woodlands and shrubland vegetation (maquis and garrigue). Typical woody species are Alnus cordata (Loisel.) Desf., Acer opalus subsp. obtusatum (Waldst. and Kit. ex Willd.) Gams, Quercus pubescens Willd., Olea europoea L., and Ceratonia siliqua L in the woodlands and Myrtus communis L., Pistacia lentiscus L., Rosmarinus officinalis L., Helichrysum italicum (Roth) G. Don, Juniperus phoenicea L., in the shrubland vegetation.

Field data were collected, in several time intervals, during the period April 2016–October 2017 and ethnobotanical information on the applications of studied plants were gathered through semi-structured and structured interviews with people who actually know local traditions [1].

The selection of people was made at random among the oldest persons who still conserve traditional knowledge about medicinal plants [6].

In the beginning part of the field study, people were invited to name all medicinal and useful plants and remedies utilized in the past. Other accurate information were registered in a second phase, through structured interviews with the aim to complete a suitable questionnaire [7] (Additional file 1).

The interviewed people were asked to provide a fresh specimen of each plant cited for systematic identification, to call it in the local dialect (Salernitan dialect of Italian language) and to show its properties, ways of administrations, and employments (in human and veterinary medicine, as human food and animal feed, in the agricultural, domestic, or handcraft fields). A fresh sample of each plant was shown to the informants to avoid a misidentification of the species [8]. In some cases, it has been asked to interviewees to show the objects named during the conversation, as crates, brooms, hand tools, and sticks. If a plant was cited without having any herbal specimen, the informant was invited to go to the field and show the named species. A careful control analysis has been made after collecting the data and identifying the species, to avoid of including non-traditional information, for example originated from books or audiovisual materials.

The informants interviewed were 70 (29 men, 41 women), whose ages ranged from 50 to 95 years, and belonged to families more representative of the area. Most of the interviewees (59) were aged over 60, of whom 40 were between 60 and 69, 18 between 70 and 90, and 1 was over 90 years old. Among the informants, 25 were farmers; the others were employed in the construction, restaurants, and sheep-farming. They all were born and inhabited in the studied area for many years. The informants know that the information they furnished will be published.

The methodology employed in this study uses the qualitative data of classical ethnobotanical-systematic research on plants, and the numerical quantitative data of consensus, following the guides for ethnobotanical studies [7‐10].

The results of the present work are compared to ethnobotanical data of contiguous zones, to confirm the medicinal uses or report some differences [5, 6, 11‐29].

Voucher herbarium specimens were compressed, classified, dried and stored in the Herbarium of the Medical Botany Chair at the University of Salerno. The volumes of Flora di Pignatti [30] were used for the classification and nomenclature of plants: finally, all the names were updated using the site http://​www.​theplantlist.​org/​.

We utilized the use value to calculate the most frequently used plants. The use value [31] was calculated to determine the relative importance of a species according to the following formula:

where, UV is the use value of the species, U is the number of informants, and N is the total number of informants.

The plants, used to cure human ailments, have been categorized into 11 categories; consequently, a single species could be listed in several illness categories (Table 2). Among these plants the highest number is recorded for UG (about 15%) and GI (about 14%) groups. Less frequently, plant species are used for OR, ENT and OP (about 2%).

One hundred and one species, belonging to 48 families, were reported for the human uses. The most cited families were Lamiaceae (11 species), Asteraceae (8 species), Rosaceae and Solanaceae (6 species).

In particular, the decoction of rhizome of Arundo donax L. was employed against gastric affections, use reported also by De Feo and coworkers [5], De Feo and Senatore [13], and Guarrera and Savo [17]. Also, a decoction of Lavandula angustifolia Mill. has a similar use.

For systematic diseases, we reported the application of flowers of Spartium junceum L. and, in particular, for the treatment of diabetes, we cited the application of fresh leaves of Artemisia absinthium L.

In the same Asteraceae family, Cichorium intybus L. and Cynara scolymus L. were reported for liver pathologies; Bellis perennis L. heads, together with Mercurialis annua L. (Euphorbiaceae), were employed as a febrifuge. In literature, other authors [5, 6, 12, 16, 17, 21, 22, 26] cited depurative and laxative uses of C. intybus.

Some species are known for their diuretic activity: the decoctions of the leaves of Borago officinalis L., Ocimum basilicum L., Asparagus acutifolius L, Morus alba L., Morus nigra L., Zea mays L., Prunus avium L. are employed for this purpose. Pieroni and coworkers [26], Savo and coworkers [4], and Scherrer and coworkers [1] cited the decoction of aerial parts of B. officinalis as a depurative.

Cynodon dactylon (L.) Pers. and Sambucus nigra L. are utilized to cure female infertility. A rhizome decoction of C. dactylon is known for its application in renal stones, as an urinary anti-inflammatory [4, 5, 12, 14, 16, 19]. The plant is also reported to cure inflammations of the digestive and genital–urinary apparatuses (diuretic, “refreshing,” renal colics) [4, 22, 25]. Cyclamen purpurascens Mill. is put under the pillow of babies who urinate in bed.

Twenty-three species are cited for their use in skin pathologies: in particular, we can highlight the use of gel from the stems of Opuntia ficus-indica Mill. as a lenitive for skin [21], a water macerate from bark of Tilia platyphyllos Scop. used on burns, the leaf oil macerate of Ruta graveolens L. as a skin anti-inflammatory and for the treatment of ophthalmic affections. De Feo and coworkers [5, 12] referred the use of O. ficus indica as a plaster: in particular, the powdered branches are used to treat corns and frostbite.

Salvia officinalis L. is directly applied on skin affected by Herpes zoster. The decoctions of leaves of Althaea cannabina L. and Cymbalaria muralis G. Gaertn., B. Mey., and Scherb. are applied externally to have an anti-inflammatory action.

The rhizome of Arum italicum L. is used as a skin decongestant: a similar use is reported by other Authors [6, 29]. Instead, Guarrera [16] and Montesano and coworkers [22] cited the topical applications of sap as healing of warts.

A wrap of Vincetoxicum hirundinaria Medik. is used against contusions and distortions; the leaves of Hedera helix L. are boiled until to be a gel which can be applied as anti-rheumatics [5, 21]; an infusion of the leaves is reported as an anti-neuralgic.

Two ways of administration of Matricaria chamomilla L. should be cited: an infusion of its flower heads with Laurus nobilis L. leaves for the treatment of edemas; a poultice of the plant, applied externally, against hematomas and traumas. These plants were reported in literature with the same uses [1, 4, 5, 12, 21, 25]. It is of interest that a decoction of flowering heads of the first plant, mixed with mallow (Malva sylvestris L.) flowers, can be used to soothe the cough.

A decoction with L. nobilis is reported against cough or belly pains, also used for goats [1]. An infusion of M. chamomilla and Lactuca sativa L. is considered an intestinal spasmolytic.

A decoction of the plant, pure or with M. sylvestris is claimed useful against cough and bronchitis [21], alone or with chamomile for digestive purpose. Moreover, a decoction of its aerial parts is reported as a mild laxative [12, 17, 22] and as a gastric antispasmodic [14].

The same parts of this plant are used for their sedative action; a similar action is possessed by an infusion of flowers of Lavandula angustifolia and Papaver rhoeas L. The same or similar use for poppy is reported by other Authors [4, 5, 12, 16, 17, 21, 26]. Di Novella and coworkers [14] cited the use of the poppy as an hypnotic.

Cigarettes made of leaves of Datura stramonium L. are used as an anti-asthmatic; this use is reported in literature [5, 14, 16, 21]. Some species of Thymus and Urtica are utilized as an expectorant also with Ceterach officinarum DC [12]; a decoction of Vitis vinifera L. is used with M. sylvestris leaves against bronchitis and a decoction of Origanum vulgare L. is used against upper respiratory affections. Menale and coworkers [21] reported the use of oregano and M. sylvestris in case of cough. Guarrera [16] indicated the use of some species of Thymus in case of colds.

Ceterach officinarum DC. is known with the popular name of “spaccapietre” (stone-breaker) due to its use, mainly in Basilicata and Puglia regions, in kidney lithiasis [14, 16].

In plants acting on cardiovascular system, Calystegia sepium L. is used to decrease blood pressure; this use was reported in Italian ethnobotanical literature [5]. The fruits and leaves of Olea europea L. are utilized for the same hypotensive effect; this use was already reported [5, 12, 16, 21, 25].

Leaves of Quercus ilex L. are employed in decoction with Urtica urens L. for gargles against throat inflammations.

We can cite the employment of fresh leaves of Foeniculum vulgare for headache. An infusion of Diplotaxis tenuifolia L. is reported as a male aphrodisiac [4, 5, 16, 17, 21].

Some preparations are based on mixtures of multiple plants, as reported in Table 3: in particular, these preparations are used for edemas, for kidney stones, and, above all, for respiratory diseases; M. sylvestris and M. chamomilla are most common plants in these multiple preparations.

In all investigated zones, the use of a decoction of some plant species, locally named “o’ ricotto,” is very diffused, mainly among the elderly. This remedy is used as a panacea to cure numerous diseases, as abdominal pains or colds. It has a very good taste, so, in many cases it is drunk with pleasure. Many interviewees give this type of preparation to ill children. In each locality, there are some people which, during spring and summer, care of collect and dry the plants to prepare this decoction.

The list of the species used for this decoction is shown below, with employed parts, taking into the consideration that each people modifies the recipe to his liking. Twenty-nine plants (reported in Table 4) were used, belonging to 18 families: Labiatae (9 species), Compositae (3 species), and Rosaceae (2 species) as the most represented.

Eight percent of the reported species are employed for veterinary uses or as animal feed. Among the four species reported for veterinary use, the macerated oil of Allium sativum L. is employed against chicken diseases. Normally, the use of Fraxinus ornus L. is very diffused for a high number of human pathologies [4, 16]; instead, we cite its veterinary use: an aqueous macerated of the plant is employed to cure cooling diseases of gallinaceans (local name “pepitola”). Also in Cilento area, a decoction of trunk barks and young branches of the plant was administered to young chicks as a gastric disinfectant [14].

Urtica dioica L. and U. urens L. are used for cattles to facilitate placental disposal; moreover, these plants are used as a feed.

Other six species reported were employed as a feed: in an age in which synthetic foods often replace natural fodders, it is worth remembering some foods of plant origin traditionally given to domestic animals. Among the new uses, we report Cnicus benedictus L. as feed for donkeys and Triticum turgidum L. as a beverages for animals: in particular, dirty dishes are washed with seed bran in hot water and therefore, this water is given to drink to the pets. It is claimed that species used as animal feed improve animal health, as well as the quality of milk and dairy products.

Wild foods constitute an essential component of people’s diets around the world [11]. In general, dishes made with wild plants are often identified as functional foods (foods with biological effects that go beyond their mere nutritional properties) and wild plants can contribute to overcoming periods of food or income shortages [11].

Thirty-six species (30%) are employed as food plants in the studied area. The plants are either eaten raw, mixed with other vegetables or in salads, when they are prepared with young and tender leaves that when picked in the early vegetative stage of the rosetta have a less bitter taste, or boiled, when harvested as older leaves, even in mixed vegetable soups [28]. The recipe of “Minestra maritata,” prepared during Easter time, is reported in Table 5: specifically, eight of these plants are Compositae, two are Cruciferae, two are Plantaginaceae, and one is of Rosaceae family.

Also Guarrera and Savo [18] cited this traditional soup of Campania region made by Cichorium intybus, Foeniculum vulgare, Reichardia picroides, Sonchus asper, cabbage (Brassica oleracea), celery (Apium graveolens L.), endive (Cichorium endivia L.), lettuce (Lactuca sativa L.), onion (Allium cepa L.). S. marianum was eaten as a snack also in Basilicata region [6, 18, 22]; moreover, the plant is eaten in salad in some Italian regions [16, 24]. C. juncea, C. intybus, C. vesicaria, S. oleraceus, and S. officinalis were cited by Guarrera and Savo [17, 18] as nutraceuticals.

C. intybus, Crepis bursifolia L., Crepis leontodonotides All., Sonchus asper (L.) Hill, and S. oleraceus are reported by Di Novella and coworkers [14] as some of the main ingredients of the “minestra terrana,” a very common soup made by 12 wild species. The ingredients are boiled in water and they are mixed with olive oil, Allium sativum, and other condiments.

Foeniculum vulgare L. is employed as a food and for the preparation of liquors. Also some species of Asteraceae are used for preparation of liquors or as food in different kinds of “minestra.” So, in literature, the leaves of C. intybus are reported added to soups, eaten as salad or fried, and finally as an ingredient of “minestra” [1, 6, 24]. S. nigra leaves are eaten cooked with eggs, while its fruits are employed in typical marmalades. Some species of Mentha are used to aromatize a typical food made of veal and pork spleen. Ceratonia siliqua L. is used as a food for children.

The leaves of Armoracia rusticana P. Gaertn., B. Mey., and Scherb., together with Anethum graveolens L. and Laurus leaves, were used as flavoring agents for pickled fruits of Lycopersicon, with water, vinegar, salt, and sugar; the remaining solution of the tomato pickling process is drunk.

In the studied area, a considerable number of plants (24%) are employed for domestic uses or in local handicrafts: Fagaceae (3 species), Urticacae (3 species), Asteraceae, Lamiaceae, and Salicaceae (2 species) are the most represented families. Cannabis sativa L. was used in the manufacturing of cordages, a key factor for city economy: Di Novella and coworkers [14] reported the stems of the plant used to obtain textile fibers. Moreover, the fibers of C sativa mixed with eggs were used to make anti-inflammatory bandages.

Daucus carota L. is reported for its use in color for paintings. We can cite the particular use of Vincetoxicum hirundinaria: a water maceration of this plant with Urtica urens leaves is sprayed on the vegetables to send away insects. The women used, to wash themselves, perfumed water obtained from the maceration of fresh flowers of Bellis perennis L. or inflorescences of Lavandula angustifolia Miller. Some plants are reported for their handmade products: the wood of Acer campestre L. is employed to make tool handles, toys, and a traditional typical musical instrument known as “ciaramella.” Arundo donax L. is used to do baskets, musical instruments, and as a support for vegetables; a similar use is reported by Di Novella and coworkers [14] and Passalacqua and coworkers [24]. Salix purpurea L. and S. alba L. are used to tie grape plants [16, 22] and to manufacture baskets (Fig. 2) [14].

In past times, Quercus species were employed to make vats, barrels, and generally tools; moreover, a diffused utilization of Castanea sativa Mill. is the construction of different shape and size barrels.

Polygonum aviculare (whole plant) is boiled to wash barrels with Foeniculum vulgare, Laurus nobilis, Nepeta cataria, and Citrus limon leaves.

The leaves of Armoracia rusticana are smoked; the leaves of Saponaria officinalis L. are used to clean the hands, especially after the production of tobacco from Nicotiana tabacum plant. This use is diffused also in other areas [14, 24].

A mix with sand, water, and Parietaria officinalis is used to clean wine stains from carboys and bottles; the same use is reported in literature [14, 16, 24].

Out of the ordinary is the use of Euphorbia dendroides L.: a water macerate is sprayed on fruit-trees to prevent theft [13]. Ceratonia siliqua seeds were used to make necklaces.

The species most cited in the study are reported in Fig. 3. Different preparations and application processes of medicinal plants used are as reported in Fig. 4. For plants not with medicinal uses, we registered two decoction preparations, eight macerate preparations, and three preparations with boiled plants. Overall, decoction and infusion are the most cited preparations. The majority of remedies were prepared from dried material. In some of cases (21), the plants are used in the fresh state. The plant parts used for these types of medical preparations are, above all, leaves (66 cases, mean UV value 0.38), aerial parts (44 cases, mean UV value 0.36), flowers, flowering tops, flowering heads (in total, 30 cases, mean UV value 0.35), fruits (19 cases, mean UV value 0.40), and barks (10 cases, mean UV value 0.29). The main parts used are reported in Fig. 5. The dosage is empirical: generally, for 1 L of water, two handfuls of plant were added.

The knowledge about medicinal plants and other useful ones is still alive, passed down from generation to generation; however, people over 50 years old has retained this kind of information.

In the investigated area, healers are still respected: some of these persons follow these practices and are proud to be the last guardians of a now lost culture; sometimes they report that they have cured some people in cases where the official medicine has failed.

Several species are harvested at dawn on St. John’s Day (June 24). The eve of Assunta day, August 14, is another important day for the collection of specific plants, known as “erve ra ‘Maronna” (herbs of Santa Maria). In popular belief, the therapeutic features of these plants are higher if these species are collected during waning moon, in a period named locally “a’ mancanza” (meaning falling moon). The plants are cleaned and divided in small pieces, mixed each other in different quantities for species, shade dried.

Data analysis showed that the people that use traditional remedies possess the knowledge of a high number of plants. This can reflect the transmission of the phytotherapeutical knowledge among the investigation area. Generally, women are depositaries of the medicamental properties of plants, also because from ancient time the female line takes care of lands dedicated to gardens and cultivation of cereals, while the male line is dedicated to pastoral activities.

Furthermore, for most plant species, knowledge appears to be homogeneous, very scarce, or unaffected by external factors. Their effectiveness can sometimes be justified not only by the known presence of active chemical substances, but also by the widespread practice and even by the observation of the concrete benefit obtained by the informer. The use of different species in different Italian areas often depends on the local availability of plants or the presence of typical species: in the literature, it emerges that some wild plants have a very limited use. Since time immemorial, plants have been the first medicines to cure diseases. Man becomes aware of the ethnobotanical application of plants through trial and error. This knowledge has been transmitted orally from generation to generation and has been applied in different parts of the world [32]. Furthermore, ethnobotanical research discovers plant resources that can be used to obtain new compounds that lead to the development of innovative drugs for the treatment of diseases [33, 34]: in fact, the discovery of new botanical drugs and new food crops depends on ethnobotanical knowledge [35]. Finally, the ethnobotanical study of medicinal plants is based on the acknowledgment of contributions made by local communities and/or by single persons who share specialized acquaintance; on the other hand, it can contribute to help native people and the preservation of biodiversity in their environments [36].

Ethnopharmacology is based on the recognition that people, throughout history, have utilized natural products as therapeutic agents and traditional medicinal knowledge can be used as a tool to obtain more information about the therapeutic capabilities of a natural product [37]. Traditional understanding is a resource that has been below estimated in the past, and the actual contribution of ethnopharmacology to drug finding has often been discontinuous.

The aim is to move forward, mainly in the context of the sources available nowadays, formalizing the use of ethnopharmacology to increase the development of drug discovery and quicken the recognition of novel therapeutics [37].

Generally, nowadays, in veterinary medicine, traditional natural remedies are substituted by synthetic pharmaceuticals for the cure of animals. In the present time, official veterinary practices take care of animal health from all point of view and affect most of the veterinary procedures realized by shepherds and farmers. However, in various areas of the Mediterranean region, such folk practices resist and natural ethnoveterinary remedies are now only rarely employed by people; the reason why these remedies are referred by few informants [27].

Some plants, different from the mixtures of herbs that are randomly collected in the field, are used as animal fodder, to maintain their good health conditions. Generally, fodder plants were picked by women near to the village, but sometimes they were mowed and piled by men in front of their house.

Some botanical foods have been cited and mentioned in several areas, showing that there is an ethnobotanical convergence between the various Italian regions [14, 15, 17, 18]. “Let food be your medicine”: the Hippocratic declaration was linked to the traditional idea of food and reflects the approach of the Greek physician to medicine, highlighting the meaning of diet and existing habits in preserving health from diseases. In fact, in ancient time, many plant species employed in the medical practice were also consumed as aliments [28]. Several plants are consumed by people because they help maintain health. These plants may have a specific use or multiple properties and are able to counter and prevent a wide set of medical conditions [17]. Edible plants should be considered for their important socio-cultural, health, and economic benefits for both local communities and farmers engaged in their production and harvesting [11].

Dietary patterns change rapidly all over the world. The local food knowledge available, which forms the basis of many local traditions, is drastically diminishing.. At the same time, consumers demand novel types of tasty food, which is easy to prepare. In the Mediterranean, vegetables and salads, made from wild greens, have been particularly important as local (traditional) foods since ancient times. In recent years, wild food plants have increasingly became the focus of attention for many ethnobotanists in Europe. There are several reasons for this: the renewed interest in local traditional foods and in plant food sources; the related concepts of terroir and intangible cultural heritage, and the potential of these foods as nutraceuticals, in the prevention of diseases [15] and in the contribution to a healthy and balanced diet [23].

The rediscovery of the folk uses of plants in the area under consideration is not only of historical and scientific value, but could also represent a future, economic potential for the area. Several plants could still today be involved in the production of typical and appealing artifacts. In particular, the production of typical objects that are now on the decline (collars, baskets, clothes of particular textile fibers, and generally the artifacts under sale) could regain importance in the local economy [38].