Non-edible mushrooms traditional knowledge
Non-edible mushrooms identified
In total, we collected 178 specimens of mushroom considered non-edible by local community members. The specimens belong to 45 genera; two from the phylum Ascomycota and 43 from Basidiomycota. With 15 families, Agaricales was the best represented Order. The genera with the highest number of species were Amanita (12 spp), Cortinarius (9 spp), Russula (8 spp), Boletus and Clitocybe (5 spp) (Additional file 1).
We identified the taxonomic species of 120 specimens, which corresponded to 100 mushroom taxa. From these, 26 are reported in the literature as edible, 20 as non-edible and 10 as toxic; edibility is unknown for the remaining species (Additional file 1). Among the species reported as edible we found: Neoboletus erythropus (hongo-rado), Hygrophoropsis aurantiaca (brindis), Clavariadelphus truncatus (bate), and others (Additional file 1).
In both communities, 14 species were recognized as non-edible, and all non-edible mushrooms were considered poisonous. Species in such categories did not show a precise pattern with regards to their biological or ecological traits. An interesting finding was that, according locals, edible ethnotaxa could become poisonous when specimens are too ripened. This is the case for Amanita rubescens (poisonous cupcake/mantecado de veneno) and Laccaria trichodermophora (poisonous xōlētl/xōlētl de veneno). Others could become poisonous when the foraging season is over, for example, Lyphyllum gpo. decastes (mushroom of the bush/hongo de mata/xolete).
Discrimination attitudes
During the ethnomycological expeditions, we observed different ways people approach non-edible mushrooms. There is a set of non-edible mushrooms that had proper names: cītlal-nanacatl and hongo-rado, which can be recognized in plain sight, even from afar. These were handled with certain affinity, familiarity and even pleasure. Nonetheless, people intentionally destroyed them as a warning, to indicate that it is a poisonous mushroom and so, to prevent others from collecting it.
Another group of mushrooms did not have proper names (shrimp (camarón) and i-tlatla in cuā-te-cax). These were handled under particular circumstances like teaching, joking, curiosity, and identity confirmation. They were smelled, tasted, observed, and destroyed. The process of discrimination was executed in three stages: doubt, verification, and confirmation (Figure 2).
The third group had not proper names and was never handled. Although we asked about these species, they were met with a clear indifference, and therefore they are not destroyed (poisonous mushroom/hongo venenoso).
Local nomenclature for mushrooms
We obtained 179 local names (76 in FJM, 87 in SIBS and 16 shared) for non-edible mushrooms, 29 in Nahuatl, 97 in Spanish and 53 mixed. Traditional names corresponded to 130 genera, 47 taxonomic species and two of superior orders. Local names did not correspond with scientific names at a 1:1 ratio; in consequence, we grouped the local names into ethnotaxa, and identified the corresponding genus and species (Table 1). In general, mestizo Spanish speakers from FJM and Nahuatl speakers from SIBS designated the names of non-edible mushrooms by drawing comparisons with edible mushrooms. Spanish local names were composed of two words: noun and modifier, while Nahuatl names were formulated with a primary and a secondary lexeme.
The primary lexeme was formed by a root or nuclear modifier that generally matched the name of the similar edible mushroom, or “edible lookalike”. The secondary lexeme or marginal modifier qualified the first and usually granted the non-edibility attribute. In SIBS particularly, the secondary lexeme was composed of the relational noun i-tlatla in that indicates kinship, and was followed by the term for the similar, edible counterpart. For example, i-tlatla in tlalpīltzal.
There was however a contrast in the nomenclature for the most culturally important non-edible mushrooms. These had a proper name that did not refer to an edible lookalike, even if one exists. Such is the case for Amanita muscaria ̶ cītlal-nanacatl/ajonjolinado ̶ and Neoboletus erythropus ̶ hongo-rado ̶ in FJM. These proper names for non-edible species could contain modifiers that indicated specific traits that act as differentiators between varieties; for example, ajonjolinado blanco de encino, cītlal-nanacatl blanco de oyamel. Up to 40% of local names were mentioned by at least four people, and in general, these names were descriptive (cuerudo [leathery], volcancito [little volcano], ruleta [wheel], vidrioso [vitrous], etc.), references to elements of the environment such as animals (uña de ratón [mouse nail], venadito [little deer], pipilo), or references to characters (señoritas [ladies], oreja de diablo [devil’s ear], etc.).
Dual worldview
People from both studied communities conceptualized non-edible mushrooms as being in conjunction with a similar edible mushroom, and this concept emanated from a perception of the duality between good (edible) and bad (poisonous). Local names were a clear example of such dual perception; in fact, people declared that to know an edible mushroom, it is necessary to know its poisonous counterpart to prevent mistakes that would put one's health at risk. In both communities, people thought that the bad is evident in the mushrooms' morphology: “Edible and poisonous mushrooms are very similar in plain sight, but if you know them well, you can see the difference between them”.
Figure 3 shows the dual perception of non-edible mushrooms mentioned by more than 10% of people from both communities. For members of the FJM and SIBS community, the relationship between edible and non-edible mushrooms was very narrow and they even considered that one cannot exist without the other. This evidenced a complementarity that maintains the balance in the universe, where there cannot be more bad than good, since good controls bad and vice versa.
In FJM, they even compared the duality of good and bad mushrooms to the birth of twins; where according to their beliefs, one will get the good attributes while the other gets the bad ones. In SIBS, people used the noun i-tlatla in meaning “the lookalike” to refer to the good and bad duality.
Identification criteria
In total, interviewees mentioned 101 identification criteria for non-edible ethnotaxa, which were grouped as 32 general and 87 specific criteria. In both studied communities, there were 34 central criteria (abundance, unpleasant appearance, change of color after rough treatment, gills, fruitbody, color of the stipe and pileus, consistency, shape and thickness of the fruitbody, absence of worms, hymenium shape, pileus ornamentation, taste, and surface area). These were the most informative, detailed, and specific criteria, and sometimes they were included in the traditional names. Conversely, many specific criteria were used exclusively in one of the two communities; 24 in FJM (for example, big loculus, flat pileus and partial veil) and 43 in SIBS (shifting color with maturation, hymenium color, leathery cuticle, small stipe, pileus size and thickness, and fast decomposition).
These identification criteria are evidence that traditional methods for mushroom identification are based on the traits of fresh mushroom, where some attributes such as color, size, texture, thickness, weight, smell, taste, consistency and biotic environment, among others, are essential to differentiate edible from non-edible mushrooms. These criteria are related to the main characteristics that are used in classic taxonomy to distinguish organisms at a generic level; for example, scales on the pileus for the genus Amanita; color change after rough treatment for Boletales; branching patterns for coralloids; dentate hymenium for Sarcodon and Phellodon, and sporome color to discriminate varieties (Figure 4).
In both villages, we observed a consensus regarding the specific identification criteria for the most culturally important non-edible mushrooms (ajonjolinado-cītlal-nanacatl, pancita venenosa-popozoh-rrabia, panté de veneno-xo-tomāh de veneno, escobeta de veneno-xelhuāz de veneno, corneta de veneno-tlalpīltzal de veneno). Meanwhile, for ethnotaxa of lesser importance, the less relevant there were, the less precise were the criteria, and there was no consensus.
Classification systems
In both communities, we identified a classification system that is based on anthropocentric utility. It established a general group, mushrooms/hongos/nanacatl, which was subdivided in two subgroups: 1) edible mushrooms/hongos comestibles/cualinanacatl (encompassing all mushrooms that are part of their diets), and 2) poisonous mushrooms/hongos venenosos/pitzō-nanacatl (encompassing all mushrooms of null or unknown edibility). However, the lexical aspects of local names as well as the identification criteria both refered to traits that can be classified into more complex subdivisions (Figure 5). This classification proposal corresponded to a hierarchical inclusion scheme that is based on the structural criteria for morphological identification (shape, color, habitat, substrate, smell, taste, consistency), to distinguish non-edible species from edible species.
Uses
In both sites, most people (55.5% in FJM and 66.6% in SIBS) stated that non-edible mushrooms are useless. However, an important proportion of the population mentioned different anthropocentric categories, such as medicine (18.5% in FJM and 11.1% in SIBS), drug (3.8% in FJM and 3.7% in SIBS) and insecticide (3.8% in FJM and 11.1% in SIBS). The use as insecticide was the most common in SIBS, and it was attributed to A. muscaria, which was also recognized as a medicine when consumed in small amounts to induce vomiting (current use) or to control tachycardia (discontinued use). This species was also reported as edible, provided the scales and cuticle are removed. Medicinal and culinary uses of A. muscaria have disappeared, since they were formerly performed by elders.
In FJM, 25.6% of interviewees mentioned that Neoboletus erythropus (hongo-rado) is traded in the main markets of Puebla and Mexico City. This commercialization is recent, and the mushroom pickers/hongueros had to assimilate the idea that this mushroom is being used as a medicine in both cities before they agreed to sell a specimen considered poisonous. Currently, there are families that specialize in collecting this species, and they obtain significant economic benefits by collecting several kilograms a day. Nonetheless, medicinal use has not yet been integrated into traditional practices in FJM, since they still consider it as a poisonous mushroom with commercial use.
Symptoms and local remedies used to treat mycetism
Most members of both communities associated the consumption of non-edible mushrooms with death (49% in FJM and 59% in SIBS). However, they acknowledged that some of them only cause specific intoxications (38% FJM and 30% SIBS), hallucinations (3% FJM) and even cancer (1% FJM and SIBS). Interviewees posed that all intoxications are not the same, but that every mushroom possesses a type of poison, and consequently, that the symptoms are specific, ranging from gastrointestinal problems to death (Figure 6).
In the two communities, a significant proportion of the interviewees indicated that there aren't any existing local remedies for intoxications caused by wild mushroom consumption (20% in FJM and 49.2% in SIBS). They considered that the only option is to consult a physician to get medication. Nevertheless, 32% of the people interviewed in FJM and 31.6% in SIBS denoted the availability of local remedies to mitigate the discomfort caused by intoxications and even to avoid death.
Traditional remedies aimed to mitigate the symptoms caused by mushroom intoxication; for example, the treatment for gastrointestinal problems is the ingestion of garlic tea, vinegar and milk, to purge the organism of the ingested mushroom, and as such, eliminate the effects of the intoxication. This remedy is followed by an infusion of peppermint, chamomile and skunk epazote to help to restore the stomach. Interestingly, SIBS habitants mentioned that ingestion of alcoholic beverages like pulque (fermented sap of some Agave species) and aguardiente (cane liquor) is one of the most effective cures to avoid death by mushroom poisoning.
In both sites, this knowledge of mushrooms was distributed within the adult population and was gender related: The women are the ones who go to the forest to forage resources and medicinal plants, while the men who devote their days to agriculture show a more detailed knowledge of the remedies and their effects against the symptoms of intoxication.
Cultural importance
Cultural importance indicators showed that the most important ethnotaxa for both communities were Amanita muscaria (ajonjolinado-cītlal-nanacatl), Neoboletus erythropus-Xerocomellus chrysenteron (hongo-rado-panté, venenoso-xo-tomāh rabia) and Suillus pseudobrevipes/S. tomentosus (popozoh venenoso, de veneno). When comparing the taxa presented in both villages, in FJM, N. erythropus (hongo-rado) was a different ethnotaxa than the rest of Boletales species; while in SIBS, this species was considered part of this group. For statistical analysis, N. erythropus was placed into Boletales (Table 2).
In FJM the most important taxa were A. muscaria (ajonjolinado de veneno), Pholiota sp. 1/Psathyrella sp. 1 (xolete de veneno) and N. erythropus (hongo-rado). The most frequently mentioned was A. muscaria (ajonjolinado de veneno) with a clear difference between this species and the remaining ones (Additional file 2). In SIBS, Boletales (xo-tomāh de veneno), A. muscaria (cītlal-nanacatl) and Sarcodon spp./Phellodon spp. (tlalpīltzal de veneno) were the most commonly cited. Although the FM of Boletales was the highest, A. muscaria (cītlal-nanacatl) was more often mentioned first, explaining its higher ordinal value of rank (Additional file 3). Also, there was no consensus between both communities regarding the status of the two most important taxa (A. muscaria in FJM, and B. aff. bicolor, N. erythropus and Xerocomellus chrysenteron in SIBS).