Diversity and traditional knowledge of medicinal plants used by Shui people in Southwest China

The study area is situated in Sandu Shui Autonomous County, a part of the Qiannan Buyi and Miao Autonomous Prefecture in Guizhou Province, Southwest China (Fig. 1). Located between the Moon and Leigong Mountains, the study area spans 25° 30′–25° 10′ N and 107° 40′–108° 14′ E. Sandu County stretches 56 km from east to west and 78 km from north to south, encompassing a total area of 2380 square kilometers [20]. This region features a low mountainous landform type, with Gengding Mountain in the northwest as its highest point at 1665.5 m above sea level. The lowest point is positioned at the terminus of the Duliujiang River, with an altitude of 303 m, while the average altitude is 675 m. The area’s climate is classified as subtropical humid monsoon, characterized by extended summers and brief winters. The complex terrain, topography, and altitude variations have allowed the county to preserve a wealth of medicinal plant resources, which support the Shui people and their medicinal practices [21]. Preliminary botanical surveys indicate that there are 736 species of angiosperms in this area, and the main timber species include Cunninghamia lanceolata, Pinus massoniana, and Phoebe zhennan [22].

In Sandu County, the Shui people account for 65.93% of the total population, and the remaining consists of Han, Buyi, Miao, and Yao sociolinguistic groups [23, 24]. The historical origins of the Shui ethnic group date back to the period before the Qin and Han dynasties. They were once part of the “Luo Yue” group, which itself belonged to the larger “Bai Yue” collective of ethnic groups inhabiting the ancient Lingnan region. Due to conflicts and wars, they migrated from the Yongjiang River watershed area, traversed Hechi and Nandan, and ultimately settled near the Guizhou and Guangxi border [25]. Over time, they gradually diverged from the “Luo Yue” group and established their own distinct ethnic identity.

The traditional culture of the Shui people still retains many elements of the ancient “Luo Yue” culture. For example, they inhabit elevated wooden structures known as Ganlan-style buildings [26]. These buildings have a dual-purpose design: the lower section serves as an area for livestock and storage of farming tools, while the upper portion is dedicated to human habitation.

The Shui language belongs to the Kam-Shui language grouping within the Sino-Tibetan language family [27, 28]. The Shui people possess their own written language, using the “Shui characters.” However, with just over 400 characters, it is a limited medium for exchanging ideas and is mainly employed for ritualistic purposes, such as worship ceremonies [29]. As a result of their long-standing interactions with the Han Chinese, nearly all Shui individuals are now proficient in both the Shui and Mandarin Chinese languages. Consequently, Mandarin has become the predominant written language in their everyday lives.

In the Sandu Shui Ethnic Autonomous County, generations of Shui people have thrived amidst the high mountains, dense forests, and warm climate. However, due to historical transportation challenges, modern medical resources are often scarce [10]. Through long-term struggles with illnesses, the Shui people have gained extensive experience in using local herbs, which they call “hama,” to prevent and treat various diseases. Within the Shui community, it is common for individuals to be familiar with several medicinal plants, leading to the accumulation of numerous medicinal prescriptions for disease prevention and treatment.

Ten field surveys were carried out from July 2015 to August 2022 (Fig. 2), which lasted for up to 3 months in total, using participatory rural appraisal (PRA) and semistructured interviews, participatory observations, and focal group discussions in the investigation sites [30‐33]. The species, habitats, and varied uses of Shui medicinal plants were collected and documented. The field surveys were carried out in six townships, including Jiuqian, Pu’an, Zhouqin, Dujiang, Dahe, and Zhonghe. The field sites were identified after researchers observed and talked with suppliers in the open markets where medicinal plants were sold.

In the Shui region, most individuals have some familiarity with herbal medicine. However, only a select few individuals are recognized as dedicated Shui healers who exclusively practice this profession. The identified Shui healers were interviewed as key informants for this study. These key informants are renowned local healers with rich medical experience and effective treatment outcomes, serving as vital custodians and contributors to indigenous medicinal knowledge. In addition, other members of the Shui community, who possess only basic knowledge of herbal medicine and do not derive their livelihood from it, were regarded as additional informants. They contributed extensive ethnobotanical data to enrich the information gathered during this investigation.

A total of 15 Shui healers were interviewed as key informants, including 2 females and 13 males. Each of the Shui healers has practiced traditional medicine for more than 25 years. They have had rich medicinal experiences and positive clinical outcomes and are recognized in their communities as important custodians and practitioners in the knowledge of traditional medicine. Interviews with key informants included discussions regarding diseases, compatibility of medicinal materials, processing and treatment methods, taboos, and means of a succession of information. In this study, local Shui healers were followed during their collection of herbal medicines in the fields and recorded the names, medical uses, and parts of the medicinal plants used.

Snowball sampling was used to identify 132 other informants, 66 males and 66 females. The methods of semistructured interviews and guided field walks and focal group discussions were adopted to collect information. The questions included the name, gender, nationality, age, family address, contact information, and other information of the informants, as well as whether they knew and used medicinal plants and the diseases that can be treated effectively.

Fresh and dried plant materials identified during interviews were collected as voucher specimens and deposited in the herbarium at the Minzu University of China in Beijing, China, for future reference. The botanical identities of voucher specimens were confirmed by the authors and other botanists at the Minzu University of China. Plant names were cross-checked with Flora of China (http://​flora.​huh.​harvard.​edu/​china/​) and digital resources from the internet, including http://​www.​tropicos.​org/​ and http://​www.​worldfloraonline​.​org.

The data were cleaned and inputted into Microsoft Office Excel for statistical analysis. An ANOVA was used to compare the number of medicinal plants recognized by herbal doctors between age-groups and townships [34]. The relative frequency of citation (RFC) was used to evaluate the most common plant species used by local healers to treat various diseases, using the following formula:where FC is the number of prescriptions mentioning the use of a plant species and N is the total number of prescriptions in this survey [35].

Information on a total of 15 local healers was collected through this study, which encompassed six townships. Healers started treating patients by setting up stalls at village fairs, inviting patients to their homes, and providing door-to-door medicinal services [36]. At the township level, Jiuqian township has five identified local healers, followed by Pu’an (3), Zhouqin (2), Dujiang (2), Dahe (2), and only one local healer in Zhonghe (Table 1). These local healers have little or no formal training or education. Their medicinal knowledge is mainly acquired through family inheritance, other healers, or self-study. The specialized Shui healers conduct their treatments in private clinics or township hospitals.

Like other ethnic minorities [37‐39], Shui communities also face challenges brought by Western medicine to preserve traditional medicine. This is because of modernization and urbanization that have resulted in fewer young people wanting to learn and practice traditional medicine. Low salary is also a fundamental issue that deters younger generations from learning traditional ethnomedicinal knowledge. As a result, the healer demographics skew older, an average age of 54, with only two healers under 40 years old. Healers were grouped by age, and a significant difference in the number of plants recognized by herbal doctors in the three age-groups (F = 54.870, p = 0.002, ANOVA) was identified (Table 2). The results show that older Shui healers have accumulated a rich experience in medicinal plant collection, identification, and treatments. However, ANOVA of the relationships among the number of medicinal plant species recognized in each township, found there was no difference in this study. This suggests that the traditional healers from different townships have a similar knowledge base of medicinal plants, and patients would likely get comparable therapy no matter in what township they sought traditional treatment (F = 0.341, p = 0.566, ANOVA) (Table 3).

As for the gender structure of the healers, the Shui traditional healers included 13 male and 2 female healers. Most Shui traditional healers pass on their medical skills and knowledge to their sons, and in some cases, their nephews. This male progenitor transmission of traditional knowledge is a common form of inheritance throughout southwest China, such as Miao [40], Yao [41], and Dong [42]. However, this male progenitor system limits the pool of potential healers to only men directly related to the practitioner, and not others in the community, including women or unrelated individuals with an interest in health. Shui men traditionally collect plants, often in remote mountainous areas, and therefore learn more about the diverse medicinal flora of the region, whereas women are more likely to remain closer to home to attend domestic duties. This cultural norm further reinforces the male progenitor custom of healer selection.

Thus, to break this male progenitor system of medical knowledge inheritance, the Shui community is encouraged to collaborate with medical colleges and universities in Guizhou to establish a department of Shui ethnic medicine. This will enable a more diverse demographic of Shui people to receive systematic education and training.

As shown in Table 2, the F statistic is 54.870, and the sig value is 0.002 < 0.01, so there is a significant difference in the number of medicinal plants recognized by healers in the three age-groups.

As shown in Table 3, the degree of freedom is 1, the F value is 0.341, and the sig value is 0.566 > 0.01, so there is no significant difference in the number of medicinal plants recognized in each township.

A total of 132 informants from different demographic groups were interviewed on the therapeutic properties of medicinal plants throughout the six townships under study. As indicated in Table 4, informants were equally divided between females and males. They constituted five age-groups falling in the range of 18–92 years, with the majority being 20–79 years. Nine young people under the age of 20 were reluctant to use herbs, and only two thought herb use was “great,” 21 people between the ages of 20 and 39 were reluctant to use herbs, and six thought herb use was “great,” while more people in their 40 s and older think of using herbal medicine first when they get sick. Moreover, people over 60 are the most satisfied with the efficacy of herbal medicine.

The results presented in Table 4 suggest that the demographic variables of informants influence the traditional medicinal plant knowledge of use and efficacy. Data on age-groups clearly show that older people rely more on medicinal plants. Many older people have gained in-depth knowledge of traditional medicine not only from their ancestors, but from their own observations over many years of utilization. Nevertheless, the lack of knowledge among younger generations may be due to changing lifestyles and waning interest in traditional medicine. These changes indicate a high risk of losing such important cultural heritage, and ways to prevent this loss are urgently needed.

A total of 505 species in 405 genera and 156 families of medicinal plants were documented in the Shui communities (Table 5). Among these 505 species, 130 species were identified for the first time as having medicinal usage, which is indicated by an asterisk in Table 5. The results also provided information on each species, including scientific name, family, Chinese name, local name, distribution, part used, use and value, preparation method, and voucher specimen number (Table 5). Compared with ethnomedicinal documentation in other communities, such as Yao people in Gongcheng County [41], Li people in Wanning [43], Bulang people in Menghai County [44], Tujia and Miao people in Jianshi County [45], Dong people in Tongdao [46] and Yi people in Shilin [47], the Shui medicinal species are especially diverse (Fig. 3). Many of the Shui medicinal plants have the typical characteristics of subtropical species. For example, herbs are mostly annual, and shrubs have strong adaptability and fast growth.