Wild Edible Plants of Andalusia: Traditional Uses and Potential of Eating Wild in a Highly Diverse Region

A review of ethnobotanical sources focused on traditionally-used wild food plants in Andalusia (southern Spain), one of the most biodiverse regions in Europe, is carried out. With 21 original sources plus some previously unpublished data, the dataset shows a high diversity of these traditional resources, reaching 336 species or c. 7% of the total wild flora. Cultural aspects related to the use of some species are discussed and data are compared with similar works. The results are discussed through the lens of conservation and bromatology. For 24% of the edible plants, informants also mentioned a medicinal use (achieved by consuming the same part of the plant). In addition, a list of 166 potentially edible species is provided based on a review of data from other Spanish territories.


Introduction
The term 'wild foods' (WFs) has been used to describe all plant resources that are harvested or collected for human consumption outside of agricultural areas, e.g., in forests, savannahs, and other shrub-land areas [1]. A wide variety of WFs, including fruits, leafy vegetables, woody foliage, bulbs and tubers, cereals and grains, nuts and kernels, saps and gums (eaten or used to make drinks), mushrooms, terrestrial invertebrates (insects, snails, etc.), honey, birds' eggs, fish, shellfish, and meat from small and large vertebrates [2] contribute to the diets of large numbers of people [3]. Wild edible plants (WEPs) and, particularly, the consumption of traditional leafy vegetables (wild or leafy greens) as an important source of micronutrients are attracting a great deal of attention. These traditional leafy vegetables represent a valuable resource in several Mediterranean countries, such as France, Greece, Italy, Spain, and Turkey [1]. This is because, among the WFs, the most diverse and most frequently gathered group is that of wild edible plants (WEPs) [3]. Although previously neglected [4], the topic is now receiving renewed attention.
Uniformity in the markets now favours the demand for different crop varieties or species, both by consumers and, consequently, companies in this sector. With this standardization of foods and ingredients, WFs can be an important source of dietary diversity. On the other hand, while a large amount of information has been accumulated on the characteristics of the domesticated species, many gaps in this information remain, particularly for species, varieties, and breeds that are not widely used commercially. Thus, information on WFs is also often limited [3]. Efforts are being made to develop a body of literature on the nutrient composition and medicinal properties of wild foods (e.g., [5][6][7]). Other data (molecular-genetic data, ecogeographical data, vernacular names, parts used, modes of preparation, specific uses, seasonal harvest and use patterns, and traditional knowledge related to various aspects of management) can all be important in planning the sustainable use and conservation of wild food species [3]. Whilst WEPs are regularly deprecated by policy makers and considered to be "weeds of agriculture," it would be tragic if this were to led to the loss of the ability to identify and consume these important available species [8].
Given the high plant biodiversity of the study area, its long history of human settlement and cultural diversity, and the availability of a considerable amount of ethnobotanical literature, the diversity of plant resources used as food in Andalusia is under-known. Our aim with this work is to make it known and to analyse its potential.
The goal of this study was to compile, describe, and assess data on traditionally used WEPs from Andalusia. As a secondary goal, we aimed to offer information regarding the potential use of other species as WEPs which, growing wildly in the territory, are also being used in haute cuisine restaurants that use wild plants in their dishes.

Results
The list of included species with uses, vernacular names, edible use categories, parts of the plants used, and original sources is presented in Appendix A. We compiled the edible uses of 336 WEPs in Andalusia, belonging to 127 genera and 70 botanical families. A total of 428 edible uses and 2435 total citations have been recorded with the described mixed method (1288 UR from informants and the rest recorded by counting the number of sources mentioning each WEP).
Outstanding genera are: Thymus, with eight species (one with two subspecies) used as seasonings; Prunus, with seven species (two naturalized and five wild) of edible fruits (e.g., the endemic Prunus ramburii Boiss.); Rumex, with seven species; and Allium, with six species of edible bulbs. Other important genera with five edible wild species each are: Asparagus (edible tender shoots), Lactuca (edible leaves), Lonicera (flowers used as a snack), and Malva (with fruits eaten as snacks and, in some species, leaves as green vegetables).
The review was focused on plants growing wild in Andalusia. Nevertheless, we also included 28 species that were considered naturalised or sub-spontaneous (e.g., Robinia pseudoacacia L. or Melissa officinalis L., Appendix A) according to Blanca et al. [36]. Cultivated Rosaceae with edible fruits can also grow near cultivated lands, but they have not been included as WEPs except for cases in which naturalization has been clearly detected and is clearly mentioned in [36] (e.g., Prunus domestica L. and Prunus dulcis (Mill.) D.A. Webb). Other cultivated species, e.g., Malus domestica (Borkh.) Borkh., Cydonia oblonga Mill., Prunus armeniaca L., Prunus cerasus L., Prunus persica (L.) Batsch, and Pyrus communis L. were logically excluded from our dataset, as were others like Diospyros kaki L. f. and Punica granatum L.
The distribution among botanical families shows that the nine most important families comprise up to 59% of the species. The main families are represented in Figure 1A. (  For 40 of the WEPs, this is the first ethnobotanical report documenting their use in Andalusia. Most of them have uses not previously reported in the territory but generally well-known in nearby territories (28 of the plants are cited in the three consulted works). These include, for example, the consumption of the leaves of Calendula officinalis L., Leontodon tuberosus L., Cardaria draba (L.) Desv., and Diplotaxis erucoides (L.) DC., as well as the fruits of Sambucus nigra L. and Crataegus laciniata Ucria. Some are locally well reputed and frequently consumed (e.g., Rhagadiolus edulis Gaertn. in rural areas of Granada province).
The distribution of the parts of the plants used ( Figure 1B) shows a higher proportion of documented uses involving leaves, which are generally used in salads or soups. It is a heterogeneous group with an abundance of Asteraceae (35 species), Lamiaceae (12), and Brassicaceae (11), as well as the frequent use of Apiaceae and Polygonaceae (9). This is followed by the consumption of fruits, such as those of the Rosaceae species; stems and tender shoots (frequent in genus Asparagus and other plants with a similar mode of consumption); and aerial parts (i.e., all parts of the plant above the ground, especially in the case of the use of the Lamiaceae as seasoning). Most of the edible uses were categorised as "food" (55,8%), but "snacks" and "seasonings" (17 and 13% respectively) also stand out.

Andalusian WEPs
As expected, among the WEPs in Andalusia, some species are widely consumed throughout many Mediterranean European countries, e.g., Sonchus spp., Crepis vesicaria L., Silene vulgaris (Moench) Garcke, Papaver rhoeas L., Borago officinalis L., Beta maritima L., Allium ampeloprasum L., Portulaca oleracea L., Crataegus monogyna Jacq., and Foeniculum vulgare Mill. (e.g., [11]). In fact, all plants with 20 or more URs (21 species, Table 1) were listed in previous reviews or datasets at both the national and Mediterranean levels [11,35] and are also widely used in other Spanish territories (see Appendix A for references). Additionally, the bromatological and phytochemical profiles of these plants have already been surveyed [7,37]. gathering is forbidden or requires special permission from the government (such as Allium sphaerocephalon L. and Ribes alpinum L. in the National Park of Sierra Nevada). Plants may also belong to a genus with other species more frequently used as WEPs (Allium baeticum Boiss. is only cited in one work, as the species is neither frequent nor abundant, but A. ampeloprasum L. is among the most cited ones). Furthermore, the local use of endemic species may be restricted to a small distribution area (Cirsium rosulatum Talavera and Valdés is only used in Cazorla and surroundings, as it is a local endemism of that territory.). Alternatively, species may be more or less widely present, but only used locally (Chrysanthemum coronarium L. was only used as WEP in Cabo de Gata). Meanwhile, plants with few recorded instances as WEPs in the form of a non-medicinal beverage were generally cited as medicinal in the form of herbal teas (Santolina rosmarinifolia L. subsp. canescens (Lag.) Nyman; Thymus baeticus Lacaita). There may also be underreported but well-known edible uses (Origanum compactum Benth., widely used in Cadiz but just cited in one work without URs; and Prunus ramburii Boiss., gathered for liquors in Granada). Finally, some WEPs may be eaten during times of famine, but while edible may not really taste good or may not provide much nutritional value. Some sources [38][39][40] distinguish between regular WEPs and plants edible only in cases of emergency after the Spanish Civil War (1936)(1937)(1938)(1939). The gathering of WEPs was a means of survival in the years of scarcity after the war, as in other territories and recent conflicts (e.g., [41][42][43]). It has been alluded that, due to the scarcity of food, the collection of wild species increased, which were not always edible [38].
Previous comparative studies within other Mediterranean countries showed that the Spanish traditionally use a higher number of WEPs (51.5% and 15% more than Italy and Greece, respectively) even though only a few species (which are widely used as WEPs) were shared between the three countries [11]. Our data show that nearly 7% of the wild plants of Andalusia have been used as WEPs (considering 4437 plant taxa; [44]). This is similar to the national ratio (7.5%, based on 419 WEPs and a total of 5537 vascular plants in the Iberian Peninsula [22,35,45]). This high amount of local wild resources traditionally used as food can be seen as a culturally positive attitude regarding the use of wild vegetables, which was described as herbophilia [46]. In this sense, Andalusia can also be seen as an herbophilic territory, in contrast with other types, such us Poland, classified as aherbous, or even herbophobous [47]. Moreover, only 58% of the included taxa (195 plants, see Appendix A) are recorded as edible in the PFAF database [48], which also compiles other important catalogues (e.g., [49,50]), denoting a high proportion of locally used or under-known plant resources.
It is noteworthy that 33% of the plants included here (121 species) were not previously reported for Spain [35] or in the two recent reviews of territories near Andalusia (i.e., Valencia [51]; and Albacete [31]). Thus, this also represents an important contribution to the knowledge of the species used at a national level.

Bromatology and Medicinal Use
While significant progress has been made in the field of WEP bromatology (e.g., [5][6][7]52]), much research remains to be done in this area. For 35 WEPs (Appendix A), nutritional values and contents are known, and food composition tables can be seen [7]. In this publication, the authors selected 41 plant species extensively consumed in the Mediterranean region (mentioned in four to sixteen different countries). It is noteworthy that, of these 41 species, only four are not cited in Andalusia. Nevertheless, the majority of the Andalusian WEPs (90%) have not been studied in detail, and the nutritional or medicinal benefits that their consumption can provide are unknown, thus representing a challenge for bromatologists, nutritionists, and researchers in the field of food science and technology.
For 83 of the plant species included in the list, informants also listed at least one medicinal use achieved simply by consuming the same part of the plant used as a food. Therefore, 24% of the WEPs can also be considered traditional functional foods, and in our opinion, this merits further study. In general, most of the medicinal uses are related to digestive dis-Plants 2023, 12, 1218 6 of 30 orders (70 plants had uses including treating gastralgia, stomach ache, parasites, diarrhoea, constipation, or as appetizers), but others relate to respiratory disorders (32 for cold, cough, bronchitis), circulatory disorders (10), or may be used as diuretics (8), or against kidney (8) or liver (5) disorders, or hypercholesterolemia (5). Some specific medicinal uses of certain species were already noted [7,22,31], but more studies on these folk uses are needed within the scope of ethnopharmacology (outside of the focus of this review).

Conservation of WEPs
Contrary to what is often assumed, evidence demonstrates that a significant proportion of wild food comes from areas used for crop and/or livestock production, or from around the home [53], and Andalusia is no exception. Most of the WF resources are collected in places with anthropogenic vegetation and in grassland and meadow zones, and it seems that people collect these resources mostly from nearby places [54].
The overuse of wild products is a major problem in many places and has implications both for biodiversity and, in the medium term, for the sustainability of the livelihoods of people relying on these resources [3]. Overexploitation is the main threat to the conservation of wild food species [3], followed by habitat alteration and pollution. Nevertheless, in Spain, studies dealing with the most diverse group of wild plants gathered for traditional medicinal practices have demonstrated that this problem is not of great concern (commercial exploitation excluded) since the vast majority of the species used do not experience problems in their conservation and, with few exceptions, are not included in regional or national conservation laws [55]. Thus, the same could be said for WEPs.
Most plant species in Appendix A are not endangered. Gathering from wild populations is only prohibited for six plant species, as they are recorded in the Andalusian list of endangered plants and mushrooms (annex of Decreto 23/2012, Andalusian Government). However, regional regulations concerning the exploitation of wild species on privately owned forest lands (Orden de 2 de junio de 1997, BOJA) also require a specific authorization in order to gather certain species (31 plants mostly Lamiaceae, marked in Appendix A). Lastly, Ribes alpinum L. and R. uva-crispa L., species frequently found in other Spanish territories but rarely in Andalusia, are vulnerable according to the standards of the IUCN [36].
The role of WEPs in cultures and agroecosystems has been outlined [12]. The simplification of the environmental structure and diversity of the farming activities is clear, as well as the influence of agriculture on the evolution of weedy species and its ecology. However, most WEPs can be considered weeds, and their ecology is to grow close to areas inhabited by humans [22,54]. Their cultivation could be a success from the perspective of the diversification and resilience of agricultural practices. Agroecological farms are particularly suitable for the cultivation of new WEPs to develop novel food products based on low-input systems and the valorization of ecosystem services. Furthermore, some WEPs are more drought-resilient than cultivated plants, permitting water-saving agricultural practices [25].

WEPs Potentially Used (PWEPs)
While the WEPs in Appendix A were recorded through ethnobotanical methods in the original sources and have a cultural background, we are aware that the real potential for wild species in Andalusia to be used as food is much higher. In order to compare the traditional WEPs with the potential of the Andalusian natural landscape, we also present (Supplementary Table S1) a table with potentially exploitable species. In this sense, we define them as potential wild edible plants (PWEPs). In order to be included in this table, the species must have met at least one of the following criteria: 1. they grow wild in Andalusia and can be gathered without cultivation; 2. they have been cited as edible in other Spanish regions (e.g., [28,29,31,35,51,56]); 3. they are currently used in haute-cuisine restaurants in the region (e.g., leaves of Mesembryanthemum nodiflorum L. or Lepidium sativum L.); and 4. they have been used as food in the past (e.g., stems of Halogeton sativus (L.) Moq.).
With these criteria, Supplementary Table S1 presents a tentative list of 166 plant species not included in Appendix A, which may potentially be gathered as food resources. Some of the species have been traditionally consumed in Spain in the past, for example, several halophytes prepared in vinegar similar to Capparis fruits (e.g., stems of Halimione portulacoides (L.) Aellen or Halogeton sativus (L.) Moq.; [57,58]). Some Aizoacae and Chenopodiaceae are currently served in luxury restaurants. Going back into history, in the Spanish-Muslim literature from the Al-Andalus period (7th to 15th centuries) we can find data on the edibility of wild plants that are no longer consumed today, either due to cultural changes or an erosion of the traditional knowledge. We highlight the edible use of Cynomorium coccineum L., mentioned by Abu l'Jayr (XI-XII centuries) and Ibn al-Baytar (XIII century) [59], as well as the use of Rhus coriaria L. fruits (sumac) as a seasoning, still frequent in the Levant. Even earlier, some wild vegetables in this table were consumed by the Romans, e.g., Crambe maritima L. [58]. Finally, we included some species that are relatives of others reported as WEPs on the basis of a probable confusion or indistinct use regarding the species (or even when recognising the genus). As an example, Appendix A lists three species of Onopordon whose leaves' midribs are eaten in times of famine in Granada, Cordoba, and Jaen. In addition, we include two more species as PWEPs for which ethnobotanical data have been reported in other Spanish territories [35].
With this section, we want to draw attention to the local potential of the plant kingdom for human food, even if there is no specific cultural basis that recognises these resources as food resources. This idea of PWEPs has already been used in other territories (e.g., [60]). In our opinion, as long as the cultural contexts of the population residing in the study area and the population interviewed for data collection on plant uses are the same, PWEPs can reflect the real potential for the use of local resources. This does not apply if cultural backgrounds are not similar. Nature is full of examples: while Solanum nigrum L. is generally considered toxic in Spain due to its alkaloids and therefore not cited as a WEP (a view also reflected in some vernacular names such as 'tomatillo del diablo'), its fruit is consumed as food in Bolivia and Peru, and its leaves in Australia, Tanzania, Ethiopia, and Somalia [61].
Adding these PWEPs to the list of WEPs in Appendix A, we achieve a total number of 532 plant species which, growing wild in Andalusia, can be freely gathered for food and reach 12% of the total flora of the region. In a review of the possible 'solutions for a cultivated planet,' the authors conclude that "the challenges facing agriculture today are unlike anything we have experienced before, and they require revolutionary approaches to solving food production and sustainability problems. In short, new agricultural systems must deliver more human value, to those who need it most, with the least environmental harm" [62]. In our opinion, WFs can meet some of these challenges, as they are foods produced with little associated environmental damage, and their cultivation and domestication can motivate this revolutionary approach for food production.

Study Area
The review covers the whole territory of Andalusia, one of the 17 autonomous communities of Spain ( Figure 2). Covering 87,268 km 2 , the region has a highly diverse physical environment, with altitudes from sea level up to 3479 metres a.s.l., several mountain ranges, a high diversity of geology and soils, and a Mediterranean climate with a great variety of microclimates [63]. Andalusia is, together with the Rif, one of the two main centres of biodiversity in the Mediterranean basin (the other includes parts of Turkey and Greece; [44,64]). The checklist of vascular flora includes 4437 plant taxa distributed across 171 botanical families [44]. It is the most diverse region on the Iberian Peninsula in terms of vegetation types [65]. . Andalusia is, together with the Rif, one of the two main centres of biodiversity in the Mediterranean basin (the other includes parts of Turkey and Greece; [44,64]). The checklist of vascular flora includes 4437 plant taxa distributed across 171 botanical families [44]. It is the most diverse region on the Iberian Peninsula in terms of vegetation types [65].  Table 2 for proper citations and territories covered in each original source. Large numbers are for provincial studies, medium for regional studies, and small for county or municipal studies.
In addition to the species, vegetation, and landscape diversity, cultural and historical factors should also be considered [66]. Andalusia is one of the most populated regions in Europe [67] and has been so since ancient times. Multiple cultures of the Mediterranean have passed through the area, which has also been central to trade with other regions of the world from the 15th century onwards. Consequently, the diversity of plant resources used in traditional ways is high.

Review Method and Inclusion Criteria
The review was focused on ethnobotanical field works which were based on direct data collection with local informants in which traditional knowledge was sought. We first selected opportune ethnobotanical literature from Andalusia, dealing with edible plants (see Table 2 for original sources, types of works, citations, and other interesting data for each). The ethnobotanical literature dealing not with edible resources, but with medicinal ones (e.g., [68,69]) was omitted.  Table 2 for proper citations and territories covered in each original source. Large numbers are for provincial studies, medium for regional studies, and small for county or municipal studies.
In addition to the species, vegetation, and landscape diversity, cultural and historical factors should also be considered [66]. Andalusia is one of the most populated regions in Europe [67] and has been so since ancient times. Multiple cultures of the Mediterranean have passed through the area, which has also been central to trade with other regions of the world from the 15th century onwards. Consequently, the diversity of plant resources used in traditional ways is high.

Review Method and Inclusion Criteria
The review was focused on ethnobotanical field works which were based on direct data collection with local informants in which traditional knowledge was sought. We first selected opportune ethnobotanical literature from Andalusia, dealing with edible plants (see Table 2 for original sources, types of works, citations, and other interesting data for each). The ethnobotanical literature dealing not with edible resources, but with medicinal ones (e.g., [68,69]) was omitted. All the original sources followed general ethnobotanical field methods based on semi-structured interviews along with the proper identification of the plant material gathered with the informants using local flora (for more details on field work, see f.i., [22,40] Benítez, 2009, or Benítez et al., 2017). Voucher numbers for each species can be consulted in the original sources. Botanical nomenclature and families were standardized using Blanca et al. [36,44] (2009) and Cueto et al. (2018). As the complete list of the vernacular names of some species is long, we only mention the most used names according to the consulted sources. This paper does not aim to review the traditional medicinal uses of the included species. The included medicinal uses from the consulted literature only apply to the edible parts of each plant and are only achieved when local people specifically eat this edible part [22] (Benítez et al., 2017). Thus, other medicinal uses involving other parts of the plant or modes of application other than ingestion (e.g., external uses) are not included (e.g., when the medicinal use requires a specific preparation other than eating the edible part or drinking the specific drink generally prepared for food and not as a medicinal beverage, it was not included).
We also report previously unpublished data on the use of some species as food. These are based on our research team's ethnobotanical records, which were collected using the same methods described above.

Categorization of Edible Uses
Using the specific consumption forms filled out by the informants, we classified edible uses into different categories: (i) foods, when ingested in any way, cooked or raw, such as when fried, boiled, used in salads or omelettes, etc., including wild fruits; (ii) snacks, when ingested only for their special, pleasant taste, such as the extraction of nectar from flowers, small fruits eaten raw without seeking any nutritional property, etc.; (iii) seasonings, when added to any traditional recipe; (iv) liqueurs, when an alcoholic beverage is prepared with a plant; (v) drinks, for plants prepared in infusions or decoctions with water without seeking a medicinal property; and (vi) curds, for plants used to make homemade cheese. In this sense, note that according to this classification, parts of edible plants eaten raw cannot be locally considered a food but a snack, either because it is seen as too small of an amount when ingested, or because the intake is valued more for its flavour than for its nutritional properties [22] (Benítez et al., 2017).
We use a mixed method to count the total number of citations for each use. For sources mentioning the original use reports (UR) for each use and species in the covered territory, we added the UR in the table of results, adding them up. For sources with original verbatim quotations, each quotation referring to the same use was counted as one UR. For sources that did not include the UR for each use (see Table 2 for details), we separately counted each source mentioning this use. Final citations were considered as the sum of the total sources without URs plus the total number of URs from sources with this data. Uses not previously reported also counted as one UR each.

Conclusions
Information on the wild species traditionally used as food in Andalusia was little known and divulged. The literature review plus a few unpublished data presented here provide data on the edible uses of 336 wild species, representing c. 7% of the total flora of Andalusia. The nutritional potential is known for only a small number of these species. However, the high proportion of species that are also used medicinally by ingesting the same part used as food (24%) is remarkable, and also means that these species can be considered as functional foods for traditional use, which deserves further study as well. Additionally, with few well-known exceptions involving species listed in the conservation laws of the territory or regionally categorised as vulnerable, the rest have no protection nor conservation problems, which supports their traditional and responsible use. Although ethnobotanical studies have already been conducted in several territories of Andalusia, there are still some territorial gaps to be covered by field research. The remarkable cultural and plant diversity of Andalusia, along with its recent history, has led to an intense and diversified exploitation of its wild resources, as presented in this study. The diversity of WEPs is presented as an agroecological solution, either by harvesting species from the wild, or by cultivating them in a low-input cost and drought-resilient type of agriculture.