General information

During field research, we recorded the use of 65 fungi folk taxa which were listed as edible. In these folk taxa, we identified 76 scientific taxa on the genus or species (Table 1). We identified 21 taxa of species considered as inedible or poisonous to the genus or species level and 3 folk taxa on levels higher than family (Table 2). We also recorded the uses of 11 fungi species or genera for other purposes than food (i.e., medicinal and hallucinogenic, Table 3). Bearing in mind that recorded folk taxa correspond to different taxonomic ranks such as genera or orders, these folk classifications can actually apply to dozens of other different scientific species, which are rare (and rarely used) but similar and related to popularly recognized taxa. Considering that in a few cases the same taxon was present on more than one list (i.e., edible, toxic, other), there were altogether 92 different fungi taxa identified to the genus or species level, recorded as used or known, now or in the past, by people living in Mazovia.

The mean number of recorded edible fungal taxa is 9.5 and the median is 9, minimum 1 and maximum 28 per interview. We detected a very small, but significant difference between men and women in relation to knowledge about wild edible fungi (Fig. 3; p = 0.0145).

According to the results, men display more diversified knowledge considering wild edible fungi than women. Men reported on average 9.9 ± 4.8 fungi taxa while women 9.1 ± 4.4. There was no significant correlation between age of respondents and number of listed edible species; however, the graph of weighted least squares regression suggests that informants aged between 60 and 70 have on average the largest knowledge of wild edible fungi (Fig. 4).

However, after removing results for ages over 70, when the cognitive capacity of informants drops, we acquired a significant correlation between these two factors (Fig. 5).

Fig. 5 Relationship between wild edible fungi knowledge and the age of the informants ranged between 17 and 70 years Full size image

The mean number of listed inedible or poisonous fungi taxa is 1.7 (median = 2, minimum = 0, maximum = 6), and the mean number of fungi taxa with other useful properties is 0.15 (median = 0, min = 0, max = 3).

Taking into account the mean number of species listed, the largest number of fungi taxa are collected in Żurawka, Mińsk county (mean = 14.7); Faustynowo, Ciechanów county (mean = 12.75); and Węgrzynowice, Tomaszów county (mean = 12.26). When all the lists from one settlement were added together, the longest lists of edible fungi taxa were acquired for Pszczonów = 41, Żurawka = 37, Szczaki = 36, and Korytów and Węgrzynowice = 33. All these villages are situated close to each other in the central and south-western parts of the Mazovia region.

Mushrooms are frequently used in a variety of boiled and fried dishes. Many taxa are also preserved (dried, pickled, or frozen after brief boiling). The range of mushroom dishes and their processing techniques is so diverse that it is worthy of discussion in a separate paper.

Diachronic differences

In the data from the 1960s, 31 fungi folk taxa were identified as listed by Mazovian informants during Gajek’s research. In comparison, current field research based only on interviews conducted in the same localities enabled the identification of 65 wild edible fungi folk species used by Mazovian communities (after the DNA barcoding, the number of identified taxa increased to 76). Only two species present on Gajek’s list were not recorded during our research (Fig. 6). These are Sarcodon imbricatus and Xerocomellus chrysenteron. Both of them were listed in Pszczonów village. In the case of Sarcodon imbricatus, it is possible that it was confused during identification with Sarcodon squamosus, which was identified in the same village during the present research and was not present in the guide used for species identification during Gajek’s research [37]. It is still possible that this species occurs and is used there. Xerocomellus chrysenteron, on the other hand, is very abundant in Mazovian forests. Further DNA barcode analysis shows that Xerocomellus species are perceived by Mazovian residents as different variants of Boletus subtomentosus and are known under one collective taxa “zajączek” (Table 4). This probably also applies to Xerocomellus chrysenteron. However, because this species was not identified by the respondents during field research or by DNA barcode analysis of collected voucher specimens, it is not included in the present list of fungi taxa known as edible in the region.

Fig. 6 The relationships between the taxa recorded in Gajek’s questionnaire from 1964 to 1969 (dotted line) and present research from 2014 to 2018 (solid line) Full size image

Table 4 The list of voucher specimens and the results of DNA barcoding Full size table

From our interviews and field observations, we hypothesize that most of the taxa not recorded in the 1960s were overlooked rather than being new uses. The local inhabitants are very conservative and cautious about fungi use and field guides tend to be used to confirm the identification of already-collected species. They usually do not start collecting new species based on the field guide. Of course, some new uses cannot be excluded. One of the respondents learned to use puffballs while receiving visitors from the UK and applied the English name, “puffball” on an everyday basis! Another example is Pleurotus ostreatus, which has not been traditionally consumed in Poland and was not present in the guide written by Orłoś [37]. Its collection from the wild became popular in the last few decades because of its broad commercial use and its presence in many modern culinary recipes.

Changes in preferences concerning wild fungi collection

Among taxa listed as edible by Mazovian inhabitants, a few species are currently considered as poisonous in Poland. These are Paxillus involutus, Amanita muscaria, Gyromitra esculenta, and Scleroderma citrinum [38, 39]. It is worth noticing that P. involutus is regarded as an edible mushroom by 38% of respondents. The reason behind this is that P. involutus was traditionally used as food in Mazovia until the 1980s, when the first reports about Paxillus poisoning syndrome were published in Poland [15]. The data on which taxa are used as food currently and which were used only in the past enable the depiction of changes in preferences concerning wild fungi collection. By comparing this data, we can see that the majority of the respondents stopped collecting P. involutus after warnings about their toxicity. However, 9% of them still claim that P. involutus consumption is perfectly safe (Fig. 7).

Fig. 7 Fungi taxa collected currently (blue) and only in the past (red) Full size image

Gyromitra esculenta and Scleroderma citrinum are usually consumed after specific preparation. Gyromitra esculenta is allowed for commercial use in Finland where it is considered a delicacy. However, it is sold only with attached instructions for its preparation [40]. Young and dried Scleroderma is used only as food flavoring, and according to some reports, it is safe to consume in very small portions [41]. It is usually used as a substitute for Tuber species; however, it is generally perceived as mildly toxic and unsafe for consumption [39, 42]. According to collected reports, A. muscaria was only used as food in the region in the past, during periods of war and famine, after long boiling and discarding of the water. This enabled the removal of toxins from its fruiting body. This method of preparation was also recorded in Italy [43, 44]. The memory of the use of Amanita muscaria was recorded in the villages of Klusek, Kozietuły, Leksyn, Psucin, and Stare Babice. While analyzing data concerning differences between taxa collected currently and in the past, we can also notice the large decline in the collection of species from Russulaceae family. This can be correlated with their absence on the list of fungi species allowed for commercial use in Poland [45], although they used to be widely collected (e.g., [14]).

Cultural significance

According to Smith’s Salience Index, the most culturally significant edible fungi taxa are Boletus edulis sensu lato (0.9157), Imleria badia (0.7959), Cantharellus cibarius sensu lato (0.7387), Suillus luteus sensu lato (0.7020), and Leccinum aurantiacum sensu lato (0.5368). The most salient inedible or poisonous taxa are Amanita sp. (0.4804), Tylopilus felleus (0.3666), Amanita muscaria (0.3048), and Amanita phalloides sensu lato (0.2767). Fungi taxa with other than culinary uses are characterized by low salience values. The most salient among them are Amanita muscaria (0.0950), Polyporales sp. (0.0187), Piptoporus betulinus (0.0158), Psilocybe sp. (0.0084), and Gyromitra esculenta (0.0027).

Folk taxonomy

The large number of interviews and frequent interaction with mushroom collectors enabled the transcription of local folk taxonomy into proper taxonomic classification. The acquired information enabled us not only to assign folk taxa to scientific taxonomic nomenclature, but also to describe folk views on connections between particular taxa.

The majority of folk fungi classifications in the study area taxa were based on units defined as folk genera [46] (or generic species [47]). Sometimes, these folk genera were universally divided into two or more folk species using folk binominals (e.g., in the case of Leccinum). Usually one, the most frequent, of the scientific species was taken as the model (“core”) of the folk genus representing its “essence” (compare [47]) and a few more closely related species from the same section were classified in the same folk genus. However, there were also instances when informants were able to distinguish other species with different local names from the core taxon based on model species. These species were divided in two groups—in a broad sense (sensu lato) and in a strict sense (sensu stricto). One such example is “prawdziwek” (porcini), identified as Boletus edulis sensu lato, within which some respondents were able to distinguish “prawdziwek dębowy” (oak porcini)—Boletus reticulatus, and “prawdziwek piaskowy” (sand porcini)—Gyroporus castaneus, though most respondents would not distinguish them. There were also cases when informants were able to distinguish a group consisting of separate taxa whose fruiting bodies had a similar appearance. This occurred with the taxa named “kozaki,” which corresponds to the Leccinum genus. Within this taxon, on the basis of different coloring, two model species, Leccinum aurantiacum sensu lato and Leccinum scabrum sensu lato were distinguished. Within the collective taxon Leccinum aurantiacum sensu lato, some of the respondents distinguished L. quercinum, L. versipelle, and L. vulpinum. Furthermore, within the group of L. scabrum sensu lato, 14 respondents were able to distinguish L. pseudoscabrum. All these species were differentiated on the basis of such characteristics as color, symbiotic relations, flesh characteristics (discoloration and density), and habitat. A similar model of classification applies to other genera such as Russula.

Classification of fungal species on the basis of the shape of fruiting bodies does not always coincide with one individual scientific genus. This happens in the case of folk taxa, known across most of the Mazovia region under the name “gąski” (literally “geese”). Because of the similarity in the shapes of their fruiting bodies, this folk taxon consists of three genera—Calocybe, Lepista, and Tricholoma. Within this taxon, Mazovian inhabitants identify species such as Calocybe gambosa, Lepista nuda, Tricholoma equestre, and Tricholoma portentosum. This was observed in the villages of Korytów, Klusek, Szczaki, and Węgrzynowice.

In the case of species from the genus Suillus, the majority of collected species are associated with the model species Suillus luteus. In folk taxonomy, Suillus variegatus is not perceived as a species associated with other Suillus species, and has different names, due to its distinctive form.

Among inedible and poisonous fungi (Table 2), a different group, which cannot be fully assigned to existing scientific taxa, is the mushrooms known as “psiaki” (literally “dog mushrooms”). This folk taxon contains all species with small fruiting bodies belonging to the Agaricales order. Another higher taxon distinguished in folk taxonomy is “huby,” (bracket fungi) which can be assigned to the order Polyporales (Tables 2 and 3). Rubroboletus satanas was described as poisonous by five respondents despite its absence in the local mycobiota. In this case, literature was the main source of their knowledge, as this species gained notoriety across the country as the most poisonous Boletaceae that can be found in Polish forests.

On the basis of collected data about the folk methods of fungi classification, we can determine the main factors responsible for folk fungi taxa differentiation. These are:

1. Order/family/genus—shape of fruiting bodies; 2. Species (in a broad sense)/section—shape, color, utilitarian properties; and 3. Species (in a strict sense)—shape, color, utilitarian properties, symbiotic relations, habitat, time of occurrence, taste, smell, flesh characteristics, milk presence, and characteristics.

Differentiation of local fungi names

Data acquired during folk taxonomy analysis enabled us to collect 526 folk names of wild growing fungi. There is visible discrepancy in number of local names assigned to particular fungi taxa. For example, 397 respondents, who have traditional knowledge about Leccinum aurantiacum sensu lato collection, listed 25 different local names of this fungus while 242 respondents who listed Lactarius deliciosus sensu lato know this taxon only under one name—“rydz”.

DNA barcoding

Edible fungi samples collected during field research were used to further DNA barcode analysis. Out of 101 samples, 88 were successfully identified using molecular analysis (Table 4). Sixty-four samples came from voucher specimens collected fresh during field research, and 24 were acquired from already dried specimens preserved by the respondents. As many as 11 of analyzed samples were not identified during previous field research; thus, the number of fungi taxa identified during present research increased to 92. Among species identified using DNA barcoding are two (Hydnum elipsosporum and Paxillus cuprinus) that are new to the mycobiota of Poland [48,49,50]. Identification of these species among other edible fungi collected by people living in the Mazovia region is also the first direct confirmation of their use for consumption.

Comparison of the results with available data

The majority of regional ethnomycological studies have focused only on fungi species used for consumption. Examples include works from Mexico, such as the study conducted in two municipalities of the Sierra Tarahumara, with 22 recognized edible folk taxa [51]; in Tsotsil town in the Highland of Chiapas with 25 edible taxa [52]; or in Amelaco, Quéretaro, where the authors were able to list 33 taxa [53]. The number of species sold in local markets in Mexico is much higher. For example, in the Ozumba market, 60 different species of fungi are sold throughout the year [54]. The same number of species was reported as sold in the markets in the city of Poznań (Poland) in the 1930s [11]. Other recent works come from the western Black Sea region of Turkey (33 edible species) [7] and Africa, such as studies from Cameroon with 22 edible fungi taxa [55], or the research conducted by Tibuhwa in rural areas of Tanzania where 75 different wild fungi species were recorded as sold as food in local markets [6]. In the case of the present research, by using both species identification in the field and DNA barcode identification, we were able to compile a total list of 76 different fungi species used as food by people living in the Mazovia region. This is the longest list of edible fungi species recorded during field ethnomycological research (one species more than the list from Tanzania). Furthermore, the complete list of 92 fungi taxa (including inedible and poisonous and taxa with other than culinary purposes) listed both during field research and molecular identification is simultaneously the longest list recorded during ethnomycological studies based on field research.

Although mushroom collecting in Poland is common and culturally salient, in other areas of Poland, only shorter lists composed of 20–30 species are known [14, 56]. Obviously, the extent of our study was relatively large, facilitating the obtaining of a longer list, but cultural factors also may play a role. Unfortunately, we do not have detailed comparative data from other Northern Slavic countries. From our preliminary unpublished observations and popular literature on fungi use, we can hypothesize that all these countries (Czech Republic, Poland, Slovakia, Belarus, Ukraine, and Russia) form something which we call the “Northern Slavic Mycophilic Belt.”

Characteristic species documented during the research

Among fungi recorded as used for consumption purposes in the Mazovia region are a few species whose collection is restricted only to particular locations. For example, Scleroderma citrinum is used as a spice for food only in villages situated in central and south-eastern Mazovia, e.g., Burakowskie, Całowanie, Łękawica, Stare Babice, and Żurawka. The collection of Calvatia gigantea, which was, by the way, protected in Poland until 2014, is popular in Flesze village, which is the northernmost studied location. The fruiting body of this fungus is usually cut into thick slices and pan-fried coated in grated breadcrumbs and egg. Calocybe gambosa is gathered in the south-western Mazovian villages of Korytów and Węgrzynowice. This species is prepared for consumption in the same way as species from the genus Tricholoma. It is used as an ingredient in soups and sauces and as a side-dish after pickling in vinegar. Residents of the south-western villages Korytów and Pszczonów often collect Craterellus cornucopioides, which is usually sautéed with scrambled eggs and used as a sauce ingredient. It is also considered a great filling for pierogi dumplings. We can also notice an interesting distribution of localities concerning the frequent collection of Hygrophorus hypothejus. The use of this species is very popular in two villages situated near the south-western border of the Mazovia region (Pszczonów, Węgrzynowice) and two villages located in the north-eastern part of Mazovia (Cieciory, Wyrzyki). This species is usually consumed as a snack after pickling in vinegar, but it can also be used as an ingredient in everyday dishes. The village of Węgrzynowice is the only location with a record of Lactarius piperatus consumption, which was used as a food only after boiling and discarding the water. Lactarius vellereus is most popular in the village of Psucin where its fruiting bodies, after a long soaking in water, are salt-fermented in a large metal vessel (called sagan). Futhermore, the village of Dąbrowa is the only one in which inhabitants distinguish Leccinum quercinum species from other orange-capped Leccinum species, and it is considered as a delicacy on a par with Boletus edulis.

It is worth mentioning that men are significantly more knowledgeable about wild edible fungi species than women (Fig. 3). This opposes the general view on wild fungi pickers based on 80 ethnomycological studies with gendered data [57]. A similarly greater mushroom knowledge among men was previously recorded in Poland [56] and was also observed in China [58].