Wild food plants and wild edible fungi of Heihe valley (Qinling Mountains, Shaanxi, central China): herbophilia and indifference to fruits and mushrooms

Wild food plant and fungi use in the world is very diverse. In many areas, mainly in urban centers or in the richest countries, few wild species are used, usually just a few wild fruits, mushrooms or green vegetables. However, in less developed countries wild food is still a significant component of nutrition. The use of wild greens and fungi shows a particularly interesting pattern as in some areas of the world these components of the diet are either avoided or little used (herbophobia and mycophobia, respectively), whereas in other areas they constitute an everyday part of nutrition [1]. For example in Amazonia and Eastern Europe wild greens are little used, in contrast to East Asia, India and parts of Africa [2]. Wild mushrooms are widely gathered in Italy, France, Catalonia, Slavic countries, Turkey, Mexico and parts of Africa, but traditionally little used in England [3]. The country the most renowned for its wide contemporary use of wild components in the human diet is China. This stems from a few factors [4,5]: (i) China frequently suffered severe food crises up until the 1960s, so the use of any natural resources was important to the inhabitants, (ii) wild plants and animals are believed to contain more “qi” (“life energy”), so they are regarded as more nutritious and healthy, (iii) Chinese culinary art likes indulging in a large number of, often strange, ingredients.

Turkey, Mexico and parts of Africa, but traditionally little used in England [3].
The country the most renowned for its wide contemporary use of wild components in the human diet is China. This stems from a few factors [4,5]: (i) China frequently suffered severe food crises up until the 1960s, so the use of any natural resources was important to the inhabitants, (ii) wild plants and animals are believed to contain more "qi" ("life energy"), so they are regarded as more nutritious and healthy, (iii) Chinese culinary art likes indulging in a large number of, often strange, ingredients.
Although the research on potentially edible wild plants has been well developed in China (e.g. [5][6][7][8][9][10]), studies focused on documenting local traditions of wild plant and fungi use using the methodology of modern ethnobotany are relatively few, and the publications in international papers solely concern ethnic minorities, i.e. Mongolians [11,12], Shaxi in Sichuan [13,14], Miao in Hunan [15] and a variety of ethnic groups in Yunnan [9,10,[16][17][18]. Two papers (in Chinese) concerning wild food resources in the Qinling Mounatins were published, but from a different part of these mountains [19,20]. The relatively short list of species given in them [19,20] suggests that only the most commonly used species were included. The ethnomycology of edible mushrooms in China is also under-developed (in spite of the extensive literature on the economic use of mushrooms in China), and particularly lacking are studies simultaneously oriented towards wild vegetables, mushrooms and fruits.
Paradoxically, little is known about wild food plant use patterns in north-central, central and eastern China where the dominant Han (i.e. "Chinese") population lives. The aim of our study was to fill this gap and to record wild food species in one little-developed, mountainous, rural area in the province of Shaanxi. For our study we chose probably the best-preserved forest complex in central China -the vicinity of the Taibai Nature Reserve, where the local population has a particularly rich choice of wild food plants and mushrooms.
The working hypothesis was that in an area of high biodiversity, in a country famous for the use of many species of wild foods, the farmers use a large number of wild vegetables, fruits and mushrooms in their nutrition, and this knowledge is widespread in the community. An additional aim was to elicit answers on the differences between present day use and use during the last widespread famine (1958)(1959)(1960).

Study area
The study was located in the Heihe National Forest Park, on the southern edge of the Taibai Nature Reserve, with the highest peak of northern China in the center of the reserve (Mt Taibai 3767 m a.s.l.). The nature reserve protects a highly diverse flora -from warm temperate (with subtropical elements) to alpine at the top. The National Forest Park (a less strict protection regime) is the southern extension of it, and mainly protects species-rich forests. The area is completely covered by ancient forest vegetation and rocky outcrops. The river Heihe valley belongs to the Houzhenzi administrative unit [town, zhen ( )], with an area of 822 km 2 . It is a very isolated place, which has vehicular access to the county town of Zhouzhi (where the post-office and schools are located) only via a 2.5 h drive through a winding precipitous gorge, often blocked for days by falling rocks. The whole valley is inhabited by 3500 people -ca. a thousand in the main settlement of Houzhenzi, and the rest in the hamlets scattered in the forest (Fig. 1).
The studied villages lie between 1000 and 1400 a.s.l. At these altitudes the climate is humid temperate, with daily temperatures in summer oscillating around 20-30 o C and winter temperatures around 10°C to −10°C. The mean annual temperature in Houzhenzi is 8.2°C, with high rainfall of nearly 1000 mm, out of which 44% is concentrated in the summer months [21]. The dominant vegetation is the species-rich Quercus variabilis and Q. aliena var. acuteserrata forest, with an admixture of Pinus tabulaeformis, and many deciduous tree species (e.g. Acer spp., Tilia spp.).
The majority of the local population are subsistence farmers who grow maize, potatoes, wheat and beans [21,22]. Sources of cash income are the orchards of zaopi (Cornus officinalis), walnuts (Juglans regia) and northern Sechuan pepper (Zanthoxylum bungeanum). Digging out medicinal roots and collecting medicinal herbs for wholesale buyers is also a very popular activity [21,22].

Methods
The field research was conducted in June and July 2011, as well as in August 2012, using transect walks and semistructured interviews with key informants, individual and group freelisting interviews (36 freelists were created), and cross-checking of the gathered herbarium specimens with key informants. Altogether, 82 people from five settlements (Houzhenzi, Diaoyutai, Huaerping, Jiangjiaping, Sanhe) took part in the study. The mean age of participants was 50 (from 16 to 83). The data were supplemented by participant observations by one of the authors (S. Y.) who had frequently visited the area, in 2007-2010, during all seasons of the year. During freelisting we separately asked, which species of wild vegetables (including underground organs), wild fruits and wild mushrooms were used. Making the three separate freelists enabled the comparison of the use of these categories and helped elicit answers from the respondents [23,24]. Freelists were made orally and written down on the spot by our team, including the Chinese-script version of the plant/fungi names.
The nine restaurants selling wild vegetables in Houzhenzi were also visited and menus were photographed in order to record the taxa sold and their price.
The study started from a few informants found using the snowball technique, but most interviewees were found by systematic walks through the village, visiting houses and asking the inhabitants if they wanted to take part in the study. We aimed at interviewing only one person from each household, only occasionally were two people from the same house interviewed, if there were signs that their knowledge differed (e.g. one of the spouses comes from another village, etc.). We also displayed some of our collections (mushrooms and some wild vegetables) in the main street of Houzhenzi, to observe the reactions and comments of people to the edible taxa shown.
Voucher specimens were collected from the specimens gathered during transect walks or supplied by informants, and are stored in the Department of Forestry, Northwest A&F University in Yangling.

General figures
Altogether, 159 plant species from 59 families (classified as 139 folk taxa) and 13 fungi taxa were mentioned by the informants as eaten at least once, but only 128 plant species and 12 fungi species were confirmed as eaten by more than one person (Tab. 1, Tab. 2, Tab. 3). The leaves and green parts of 104 species have been used, roots/rhizomes/tubers/bulbs of 18 species , flowers of 4 species and fruits of 36 species. Respondents mentioned wild vegetables most eagerly, and generally had problems listing wild fruits and fungi, stating that they are unimportant and are collected rarely. The gathering of young shoots of Celastrus orbiculatus and Staphylea spp. (mainly Staphylea bumalda, also S. holocarpa) was mentioned by nearly every respondent. Over 50% of respondents also mentioned gathering the young shoots or leaves of Caryopteris divaricata, Helwingia japonica, Pteridium aquilinum, Pimpinella sp., Amaranthus spp., Matteucia struthiopteris, Allium spp., Cardamine macrophylla and Chenopodium album (Fig. 2, Fig. 3). Six wild vegetables are served in most local restaurants (Tab. 3). Only one species of fruits (Schisandra sphenanthera) and none of the mushrooms were mentioned by over half of the respondents.
The domination of wild vegetables in foraging activities is also confirmed by the fact that they are the only category of wild food stored for winter. Drying is a very common preserving technique (Fig. 4). Households dry between 1-5 species each year, usually a few kg of dry shoots and leaves, but some households who host tourists [so called "nong jia le" ( )] can even dry a few dozen kg of dry "ye cai" (wild vegetables). Particularly large amounts of Chenopodium album are dried, as they are often used as winter fodder for pigs as well. Other commonly dried foods include Staphylea spp., Helwingia japonica, Celastrus orbiculatus, Toona sinensis and Cardamine macrophylla. Also, plants which are usually not treated as "ye cai", but as pig food (e.g. Artemisia subdigitata), are dried for the animals. In 2011 and 2012 dried Staphylea shoots were sold at the local food shop in Houzhenzi at 40 ¥/kg. Dried Chenopodium was, in 2011, sold to tourists a few km before entering the village, along with dried Auricularia and Lentinula mushrooms. Most families dry 1-5 species of wild vegetables outside on the concrete, on mats or inside the house on newspapers. Formerly wild vegetables were lacto-fermented, but now this is done very rarely.
Forest species, species of grasslands and forest edges as well as ruderal species are well represented in the list of collected taxa (however typical forest species dominate with 44% taxa, only 15% taxa are ruderal species, the rest are ubiquitous species or species of intermediate successional stages). The ruderal species are collected near homesteads. Their growth is often promoted. For instance when a farmer sprays their Cornus officinalis plantation with glyphosphate, they leave a clump of wild vegetables unsprayed. One of the most protected species is Chenopodium album, which is harvested and dried at the turn of May and June. Some forest species are harvested up to 5 km from the villages, up to the altitude of 1800 m a.s.l. At even higher altitudes, wild plants are only harvested while collecting medicinal herbs, which grow even higher.
All the older informants were asked about plants eaten during the severe food shortages that plagued China until the last case of famine in 1958-1960. The usual response was that they ate the same species but in larger quantities. They said that they were lucky having so many wild vegetables around, as some people from other, more populated areas had to take refuge in their mountains to avoid starvation. However, asking questions about the last time the particular species was used revealed that there is a group of taxa which could clearly be called famine plants -species, which were used in this area until the mid-20th century and are not used any more. These include: the leaves of Abelia engleriana, the rhizomes of Pueraria lobata, Pteridium aquilinum, Polygonatum spp., Sinacalia tangutica, the bulbs of Lilium giganteum and other Lilium species, and the bark of Ulmus spp. Nowadays the consumption of underground organs of plants has practically ceased and is restricted to the occasional use of Lilium spp. and Stachys affinis.
Wild vegetables are eaten in any of the daily three meals. The commonest preparation technique is boiling, then straining and sprinkling them with some oil in which Sechuan pepper, garlic, and sometimes ginger, was fried. Then they are served, warm or cold. This is a side dish, called "liang ban", accompanied by home-made wheat bread ("bing"), rice or other stirfried foods. Sometimes wild vegetables are also put into broad, home-made noodles served in spicy and sour soup. They are also, rarely, lacto-fermented. Dried vegetables are first soaked in water for a few minutes or hours and then used like fresh vegetables. Some respondents say that in the case of Staphylea shoots, drying even improves their taste and digestibility. Wild vegetables are also sold in all the local restaurants (Tab. 2), and every agritourist farm has them on their menu.
Fruits are and have always been less appreciated than wild greens. They are sometimes collected for fun by children or grown-ups going to the forest to collect wild greens, medicinal herbs or wood. They have never been stored for winter and are not used in any dishes by anyone, apart from dried Schisandra and Akebia fruits, used medicinally. In spite of this, most people easily mentioned a few species of wild fruits they had eaten.
Few fungi species are used, as most of them are generally feared. We found only one inhabitant of the valley, who had a hobby of collecting wild edible mushrooms, which he developed after gathering Boletus species for sale a few years ago. Others never go to the forest with the purpose of collecting mushrooms, apart from going to collect cultivated Auricularia and Lentinula edodes grown on piles of logs located in the woods. The only mushrooms relatively more widely known and accepted are Cantharellus cibarius, an unidentified Agaricales (called "banlijun", i.e. "chestnut mushroom"), Ramaria spp. (and possibly Clavaria spp.) treated by locals as one folk taxon "shuabajun" (i.e. "brush mushroom") and Grifola umbellata, whose sclerotia are collected for medicinal purposes, although fruiting bodies are occasionally eaten as well. However, only a third of the respondents have ever eaten the most commonly listed mushroom, Cantharellus cibarius. More than half of the respondents had never collected wild fungi in the forest. A few people who eat Boletus spp. species started doing so after taking part in commercial mushroom collecting a few years ago.

Discussion
The large number of used wild greens in this study is one of the highest recorded on such a small scale in the history of ethnobotanical studies. The only comparable study, by Zou [15], recorded the use of 335 taxa of wild vegetables, belonging to 87

Tab. 3 (continued)
Frequency: **** > 50% of respondents; *** > 1/4 of respondents; ** > 1/8 of respondents; * 1/8 of respondents or less, but at least 2 respondents.  families and 119 genera in 10 villages of Hunan, however the latter study concerned a larger and more heterogenous area. Ghorbani [16]  Knowledge of wild vegetables in China is additionally encoded in the language. Most wild vegetables have the word "cai", i.e. vegetable, so it is enough to know the name and to be able to recognize the plant to be able to presume its use, i.e. if it is a "cai" (vegetable) or "cao"/"yao" (medicinal plant).
The relatively high geographical diversity of the use of "ye cai" in China should be emphasized. For example none of the articles on wild vegetables of Qinling Mts mention the use of Staphylea spp. nor Pimpinella sp. -locally important vegetables [19,20].
The widespread phenomenon of drying wild vegetables is worth attention. This ancient preservation technique is nowadays rarely used for wild vegetables across the globe. Storing a particular food for winter may mean that this is a culturally significant item.
Several taxa are semi-domesticated, and undergo varying degrees of active protection. Some are increasingly brought from the forest to be planted in gardens (Toona sinensis, Staphylea bumalda, Asarum sieboldii). The two species of mushrooms widely cultivated using tree logs left in the garden or in the forest, Auricularia sp. and Lentinula edodes, were mentioned by some respondents as wild vegetables as well. This shows that, similarly to other geographic areas, the distinction between the wild and the cultivated is not usually sharp [2,25,26].
The local population utilizes a large proportion of the local edible flora. However, strong cultural biases can be seen even in such a herbophilous community. Some edible wild vegetables, e.g. Galinsoga sp., Reynoutria japonica, most Polygonum species and Lamium barbatum are not used, the common Stellaria media, is also eaten rarely and only by a few individuals.
Over half wild vegetables come from the forest. This is in contrast with some studies showing that human populations, even in wooded areas, tend to over-utilize the ruderal flora [27,28]. Here, at least two explanations are possible: (i) the fields' area is relatively small, so in the past the volume of wild vegetables from ruderal sites may not have been sufficient, (ii) many edible ruderal taxa are regarded here as pig food, and we observed some degree of separating wild vegetables for human consumption and pig food (the exception here is Chenopodium, eaten both by humans and pigs).
What is interesting is the large domination of wild greens over fruits and fungi. A typical answer of a respondent to the question about what wild veg they had eaten was: "ye cai hen duo" (there are many wild vegetables). On the other hand, the same question about fruits or fungi resulted in the opposite answer, e.g. "ye mogu/junzi hen shao" (there are very few wild fungi).
Wild vegetables are intentionally collected here, they are well known to everyone and dried for winter in most houses. Fruits are something unimportant, play objects, something one finds on a forest walk to collect herbs, something only eaten raw. They are never cooked or dried or added to any dishes. The only exceptions are the fruits of Schisandra, which are dried and sold as medicine. The lack of interest in mushrooms is puzzling, as China is usually regarded as a mycophilous part of the world [3,29,30].

Conclusions
The studied community displays one of the highest levels of herbophilia known in human cultures. On the other hand the community shows relative indifference to wild fruits and fungi, which are rarely collected, and only as an additional activity.
The results of this study show that further in-depth ethnobotanical research is needed to determine patterns in wild food plant and fungi use in different parts of China, as locally these patterns may be extremely variable.