Background

Tea (Camellia sinensis (L.) Kuntze) is among the world’s most widely consumed beverages and embodies numerous economic, health, and cultural values [1,2,3]. Over two-thirds of the world’s population drank tea, and approximately two billion cups of tea are consumed daily [4]. In general, the plant species used to make various tea, including Green Tea, White Tea, Black Tea, and Pu’er Tea, belong to the subgeneric group Thea of the genus Camellia [5, 6]. However, many other plant species, which are not belong to Camellia, have been widely used as herbal tea or substitute tea [7,8,9,10].

Herbal tea, defined as water-based infusions/decoctions prepared with herbal ingredients other than Camellia sinensis, is used medicinally by indigenous and local peoples for improved nutrition, prevention, and treatment of health problems [11,12,13]. Usually, herbal tea may consist of one or several plant species prepared using poach, infusion, or maceration [14]. They are typically made from different plant parts, such as leaves, stems, fruits, flowers, seeds, and barks, intended to achieve a specific purpose, including relaxation, rejuvenation, or relief from a specific condition [15]. Nowadays, herbal tea is becoming increasingly popular worldwide due to their diverse biological properties (e.g., fragrance, taste, antioxidant properties, and so on), cultural and religious principles, and complementary effects [16,17,18].

China has a long history, rich biodiversity, and diverse ethnic culture. Over the long history, different linguistic groups have accumulated traditional knowledge of using herbal tea to treat diseases [17]. It is estimated that a total of 782 plant species are used as herbal tea in China, and 82% of the total species are used in Southern China [11]. For example, 222 ethno-taxa corresponded to 238 botanical taxa (species, varieties, or subspecies) that were recorded as herbal tea in the Lingnan region of Southern China [17].

Guangxi, an autonomous region of multiethnic groups living together with Zhuang people as the main group, is in the southwest of China. Due to the unique geographical location and superior climatic condition, Guangxi has rich natural resources [18]. Especially for plant species, Guangxi has 8562 known species of wild vascular plants, ranking top three in the country after Yunnan and Sichuan. Herbal tea drinks are popular in Guangxi and play a crucial role in protecting their health during long-term life practices to defend the heat and humidity [19]. Our previous ethnobotanical investigation found that herbal tea in Guangxi is fully popular as a daily practice by local people [20,21,22]. However, there have been only sporadic reports on the research of herbal tea in Guangxi, and these studies have not investigated the herbal tea comprehensively, especially lack of evaluation methods using quantitative indices [7]. Guangxi herbal tea has a long history, and there are many kinds of herbal tea exhibiting their own characteristics in different regions of Guangxi. These characteristics and traditional knowledge of herbal tea are urgently needed to be protected due to habitat loss, influence from mainstream culture, and modernization [23, 24]. Therefore, ethnobotanical research is necessary to investigate and document the herbal tea in Guangxi to inform conservation efforts of biocultural diversity toward supporting environmental and human well-being. On the other hand, the study and development of those herbal tea may bring new health benefits to human society or make better economic value for local communities.

To record and better understand the traditional knowledge and characteristics of Guangxi herbal tea, we carried out a comprehensive ethnobotanical investigation across Guangxi and conducted systematic evaluation on the plant species, cultural significance, health consistency, regional characteristics, and the challenges of the herbal tea in Guangxi. Given this, the objectives of this study are as follows: (1) How many herbal species have been used traditionally; (2) How and why the local people used the herbal species; (3) How to evaluate the importance of herbal species to local people and which plants are special. Obviously, this study will facilitate the protection and development of Guangxi’s herbal tea.

Methods

Study area

Guangxi Zhuang Autonomous Region is located in the south of China, between 104°28′–112°04′ E and 20°54′–26°23′ N, including 14 prefecture-level cities and 111 county-level administrative regions [20]. It covers an area of 237,600 km2. It is located at low latitude, with the tropic of cancer crossing the central part, the tropical ocean to the south, the Nanling Mountains to the north, and the Yun-Gui Plateau to the west. It is a tropical and subtropical monsoon climate zone. The complex and varied geographical environment and the excellent climate provide suitable conditions for rich biodiversity. Meanwhile, Guangxi is an autonomous region inhabited by many ethnic groups, including Zhuang (31.36%), Yao (3.7%), Miao (1.1%), Dong (0.7%), Mulam (0.4%), and Maonan (0.17%) [25]. They have created an effulgent art and culture, especially the tea culture [19].

In addition, the previous ethnobotanical studies on herbal tea in Chaoshan [26], Fujian [27], and Taiwan [28], were selected for comparison with Guangxi in order to illustrate whether geographical and cultural differences affected the choice and use of herbal tea species in Guangxi. Chaoshan region lies in eastern Guangdong (a province next to Guangxi) and has a subtropical marine climate. Because of its abundant rainfall and sunshine, herbal tea drinks are very popular in this region for clearing heat [26]. Two Han branches (Chaoshanese speaking Chaoshan dialects and Hakka speaking Hakka dialects) are the main populations living in the Chaoshan region [29]. Fujian, which is adjacent to Chaoshan region, is located in southeast China. The sultry and humid subtropical monsoon climate in Fujian contributes its rich biodiversity, including many herbal tea species [27]. The Han Chinese including Hakka people are the main population in Fujian. Taiwan faces Fujian across the sea and has tropical and subtropical monsoon climate, which lead to hot and humid weather in summer, and local people consume herbal tea to clear heat and remove dampness [28]. In Taiwan, the population is composed of Han people (97%, including Hakka), aboriginals (2%), and others (1%) [28, 30].

Ethnobotanical survey and data collection

Field surveys were conducted based on the five surveys between October 2016 and May 2021. The Snowball sampling method was mainly used for the participant selection, and the semi-structured interview was mainly used to collect related information about herbal tea. Before each interview, prior informed consent was requested throughout the study [31]. After obtaining permission, various participants (farmers 23%, vendors 25%, village leaders 12%, religious leaders 4%, and traditional healers 36%) were interviewed. Based on the records from references, suggestions from local government, our knowledge and experience, and the results from snowball interviews, 51 villages and 21 traditional markets in Guangxi were selected as study locations (Fig. 1, Additional file 1: Table S1). A total of 463 informants were interviewed between 21 and 70 years old from these study locations to record plants used for herbal tea and document traditional knowledge of their habitats, used parts, medicinal effects, and preparation methods (Fig. 2), in which the habitats, including cultivated, wild, and cultivated or wild, were defined according to whether or not the plants grown with artificial care. Of the informants, 80% were over 45 years old, most had a low education level, and these informants were almost equally male and female. Product samples and voucher specimens were collected from markets, mountains, forests, and farming fields. In addition, photographs to record all plant species and gathering activities were taken simultaneously. Voucher specimens of all plants available during field investigations were collected and deposited in the herbarium of Guangxi Institute of Traditional (GXMI), Guangxi Academy of Traditional Medical and Pharmaceutical Sciences. Product samples, voucher specimens, and photographs were identified and confirmed referring to Flora of China, Flora of Guangxi, and botanical Web sites (e.g., http://www.tropicos.org/, http://www.cvh.ac.cn/search, http://www.plant.csdb.cn/).The botanical names were listed following Plants of the World Online database (https://powo.science.kew.org). Finally, the identified specimens were confirmed by other taxonomists from GXMI and completed the inventory of plant species consumed as herbal tea.

Fig. 1
figure 1

Locations of the ethnobotanic investigation on herbal tea in Guangxi

Fig. 2
figure 2

A Ethnobotanical investigation of herbal tea; B–D herbal tea plants in medicinal markets

Data analysis

Data analysis was carried out to evaluate how important and indispensable the herbal tea species are to local healthcare and daily diets. The taxonomic diversity, used parts, preparation methods, and categories of health-promoting were counted and analyzed. Moreover, three indices were applied to furtherly estimate the importance of certain species to the local community, which were named the relative frequency of citation (RFC), the informant consensus factor (ICF), and the cultural food significance index (CFSI).

The RFC was performed to quantify the use frequency of certain species, which was determined using the following formula:

Relative frequency of citation: \({\text{RFC }} = {\text{ FC }}/{\text{ N}}\).

FC refers to the number of respondents who mentioned a particular herbal tea plant, and N represents the number of informants participating in the survey [32, 33].

The ICF was used to measure the agreement among informants on the health-promoting effects of each herbal tea plant. The value was calculated following the formula:

Informant Consensus Factor: \({\text{ICF}} = \, \left( {{\text{Nur }} - {\text{ Nt}}} \right) \, / \, \left( {{\text{Nur }} - \, 1} \right)\).

Nur is the number of informants reporting a certain health-promoting effect, and Nt is the total number of herbal tea plants used for the particular health-promoting effect [34].

The CFSI elaborated to evaluate the cultural significance of herbal tea plants by following the formula:

Cultural food significance index:\({\text{CFSI }} = {\text{ QI }} \times {\text{ AI }} \times {\text{ FUI }} \times {\text{ PUI }} \times {\text{ MFFI }} \times {\text{ TSAI }} \times {\text{ FMRI }} \times 10^{ - 2}\).

Seven indexes in the formula expressed the frequency of quotation (mention) by informants (QI), the availability of a plant (AI), the frequency of utilization (FUI), the used parts of the plant (PUI), multi-functional food use (MFFI), the taste score appreciation index (TSAI), and the food-medicinal role score (FMRI), respectively [35,36,37].

Results

Diversity of herbal tea plants in Guangxi

Our investigations showed that 155 plant species were used to make herbal tea in Guangxi. Ethnobotanical information of each species, including family, scientific name, Chinese name, habit, parts used, preparation and uses, habitat, materials status (dry or fresh), health-promoting effects, RFC, CFSI, and voucher number, is listed in Table 1.

Table 1 Local herbal tea plants in Guangxi Province

Family distribution

The most frequently used families were Lamiaceae (11 species), Orchidaceae (10 species), Theaceae (9 species), Fabaceae (9 species), Rubiaceae (7 species), Cucurbitaceae (7 species), Aquifoliaceae (7 species), Poaceae (6 species), Loranthaceae (5 species), and other 40 families contributing 84 species are represented mainly by four or fewer entities (Fig. 3A).

Fig. 3
figure 3

A Family distribution of herbal tea species; B Life form of herbal tea species; C Use parts of herbal tea species; D Preparation methods of herbal tea species

Habit and habitat of herbal tea

For the habit of 155 herbal tea species, the most frequent species were herbs, represented by 49 species, followed by shrubs with 46 species, trees with 36 species, and lianas with 24 species (Fig. 3B). In addition, most of them (124 species, 80%) were obtained from wild habitats, whereas only 20 (12.9%) species were cultivated, and 11 (7.09%) species were wild or cultivated. Similar findings were reported by other studies from China [11, 23]. Local people believe that wild plants are healthier than cultivated ones. In addition, they prefer dry materials because they believe that it would taste better than fresh ones. Also, dry materials are easier to store and more readily available when guests visiting.

Parts used

Local people in Guangxi use different plant parts to prepare herbal tea, and two parts can be used in some species for tea preparing (Table 1). The leaf was the most commonly used part, represented by 45 species, followed by whole plant with 36 species, branch and leaf 31 species, flower 22 species, and fruit 7 species (Fig. 3C). Other plant parts, including seed, root, bark, tuber, peel, and rhizome, are used less frequently. Leaves are more accessible in people’s daily lives. They are more likely to be tested by humans for the first time and learn from other animals’ behavior. Some herbal tea varieties were made from young leaves because they are similar in shape to Camellia sinensis, such as Adinandra nitida, Eurya chinensis, and Maesa japonica. This is one of the reasons for leaves was the most commonly used plant part of herbal tea [11, 22].

Preparation methods and materials status of herbal tea

Different plant parts may subject to different preparation methods for herbal tea drinks make. Three different modes of preparation were documented in this study. Decoction was the most commonly used processing method, represented by 115 species, followed by soak with 36 species. Four species (Chamaecrista mimosoides, Chamaecrista nictitans, Senna sophera, and Senna tora) were used soak after stir-fry (Fig. 3D). Some parts like stems, whole plants, barks, and old leaves are often processed by decoction, but young leaves and flowers are preferable to soak. The decoction is widely used in rural areas, while urban populations prefer the soak. Some herbal tea, especially cooling tea, can be served with sugar by urban people. Conversely, rural inhabitants prefer to drink the herbal tea without adding anything else. Most herbal tea preparations involved using single plant species or a single plant part, such as the stems of Neocinnamomum delavayi was cooked as herbal tea to prevent cold and cure infantile diarrhea, treat most distinguished guest, and ceremony festival by Zhuang people in Napo County, western Guangxi, while other parts of this species were not used as herbal tea in this area. According to our investigation and documentation, only a few herbal tea varieties were used to mix with traditional tea (Camellia sinensis), such as Jasminum sambac, Zingiber officinale, and Osmanthus fragrans, to obtain special aroma and taste. In the UK, Ireland, Canada, and India, milk is typically added into tea, while it is more common to take tea with lemon and honey in Eastern Europe. Several studies have shown that preparation conditions greatly affect the amount of extracted bioactive compounds such as polyphenols [38, 39].

Health-promoting effects and ICF of herbal tea

Various health-promoting effects of herbal tea consumption have historically been recognized by Chinese people [40]. Based on our investigation, a total of 141 herbal tea species have auxiliary efficacy, which is over ninety percent of our reported herbal tea in this study. Clearing heat away was the most common auxiliary efficacy, followed by detoxifying, improving blood circulation, cold and cough, tonic, and aid digestion (Table 2). Moreover, other auxiliary efficacies were expressed in a few numbers of herbal tea, such as alleviating a hangover, anti-inflammatory, antiviral, antitumor, calming the nerves, refreshing, anti-diabetes, treating headache, helping saliva producing and slake thirst, regulating qi, relaxing tendons, and activating collaterals (Table 2).

Table 2 Informant consensus factor by categories of health-promoting effects in the study area

Forty-one diseases reported by the informant were divided into eight categories. The ICF values for all disease types ranged from 0.42 to 1 (Table 2). The kind of disease with highest in ICF was the aiding digestion (1.00), followed by the tonic (0.73), eliminating dampness and diuresis (0.71), removing cold and cough (0.68), improving blood circulation (0.58), and clearing heat away (0.56). The high value of ICF for aid digestion, tonic, and eliminating dampness and diuresis may be due to the limited number of reports and information. The Nur and Nt of tonic (34, 10), removing cold and cough (32, 11), improving blood circulation (39, 17), and clearing heat away (101, 45) were all relatively high, indicating that local people had high consistency in these health-promoting effects of herbal tea.

Evaluation of herbal tea based on RFC and CFSI values

Relative frequency of citation (RFC) and cultural food significance index (CFSI) were applied to evaluate the important herbal tea in this study (Table 3). RFC reflects the relative importance of certain plants in a particular area. The RFC values of all herbal tea ranged from 0.002 to 0.773, among which the highest one was Siraitia grosvenorii (0.773), followed by Zingiber officinale (0.745) and Chrysanthemum indicum (0.704) (Table 1). The values of the cultural food significance index (CFSI) varied considerably from one species to another, with a minimum of 0.7 and a maximum of 5370.0. The most culturally significant herbal tea species were Siraitia grosvenorii (5370.0), Plantago asiatica (4664.4), Gynostemma pentaphyllum (3244.8), Zingiber officinale (3105.0), Pholidota chinensis (2885.6), and Morus alba (2466.0) (Table 3). Some species used for herbal tea are displayed in Fig. 4, and the details in the calculation of CFSI for each species are provided in Additional file 2: Table S2.

Table 3 Evaluation of herbal tea plants using CFSI (> 1000) and RFC index
Fig. 4
figure 4

Some herbal tea plants. A Ilex kudingcha; B Sarcandra glabra; C Plantago asiatica; D Centella asiatica; E Gynostemma pentaphyllum; F Siraitia grosvenorii; G Zingiber officinale; H Morus alba; I Lithocarpus litseifolius

Special and representative herbal tea in Guangxi

In addition to the herbal tea plants selected by the index, there are some particular and representative herbal tea plants in Guangxi, such as Adinandra nitida, Neocinnamomum delavayi, and Hedyotis effusa.

The young leaves of A. nitida are commonly used as Shiya tea (石崖茶) among rural communities. However, according to our investigation, some Yao people also collect its flower buds to make herbal tea, with clearing and detoxifying effects, and restraining and sterilizing bacteria. Prices vary enormously from buds to leaves. The flower buds are much more expensive. Currently, the complexity of abstraction and refined productions of buds are rare. The best time for collecting A. nitida is from middle May to early June. The brief preprocessing is as follows: firstly, dry the buds of A. nitida in the sun for one day or so, then bring them out of the direct sunlight for 2 or 3 weeks at a cool, well-ventilated place. It is light yellow color and intense flower fragrance, and a full-flavored palate that is unique yet smooth, with a memorable aftertaste.

The leaves of Neocinnamomum delavayi are common ingredients of Chinese herbal remedies to treat wind–dampness arthralgia syndrome, bruises, and wounds bleeding effectively. For Zhuang people lived in Pingmeng Town, Napo County, western Guangxi, the local people cut the stems into several pieces, then put them in a pan and cook, occasionally stirring, until red and just cooked for 4 to 5 min. This tea is used for a ceremony by the Zhuang people. The gift of hospitality is dedicated to the most distinguished guests. According to the villagers, the tea can prevent from getting cold and cure infantile diarrhea. However, current phytochemical research on N. delavayi is mainly focused on the chemical components of volatiles extracted from leaves. The pharmacological activity of this plant and its role in the human body are ignored.

Hedyotis effusa, also known as a Longgougan, is a medicinal plant in Fangchenggang and Qinzhou, which is easy to find in the variety of medicinal markets. The population of H. effusa once puzzled and fascinated us for a long time. Therefore, an efforted interview with the local people was conducted. According to the interviews, inhabitants are predisposed to get inflamed by the damp and muggy climate, boiling H. effusa for a tasty way to beat every summer’s heat.

Comparison of herbal tea between Guangxi and other neighboring areas

Herbal tea or cooling tea drinks were popular in Southern China and widely used for healthcare due to the damp humidity and heat levels of this area. In addition, rich cultural diversity of Southern China was presented with numerous Chinese minorities distributed in this zone. Therefore, to illustrate whether the geographical and cultural difference affected the choice and use of herbal tea species in Guangxi, we compared the species in our study with previous investigated herbal tea materials in Chaoshan [26], Fujian [27], and Taiwan [28] (Fig. 5A).

Fig. 5
figure 5

Comparison of herbal tea species between Guangxi and other areas in China. A The geographic distribution of the compared regions; B Venn diagram for the comparison of the plant species from different regions; C proportions of overlapping plant species used between Guangxi and neighbored regions

A Venn diagram was made to visualize herbal tea species consumed in four places. The results showed that there were 9 species both in Guangxi and Chaoshan, 7 species in Guangxi and Fujian, and 2 species in Guangxi and Taiwan (Fig. 5B). Moreover, there are 6 plant species (Centella asiatica, Houttuynia cordata, Imperata cylindrica, Morus alba, Plantago asiatica, and Prunella vulgaris) used among the four-place comparison (Fig. 5B). It is proposed that these species grow in these compared regions due to the similar natural environment conditions, and benefit to the local people’s health on preventing or treating common diseases in similar environment and climate. Remarkably, 122 (78.71%) of the 155 raw materials were used only in Guangxi (Fig. 5B–C), indicating that Guangxi also has its own special selection of herbal tea raw materials based on the unique composition of ethnic minorities and culture.

Discussion

Healthcare effects and safety of herbal tea consumption in Guangxi

Various health-promoting effects of herbal tea consumption have been historically recognized by Chinese people [40]. In this study, the most frequently mentioned healthcare functions of herbal tea were to clear heat away, represented by 101 species (65.16%). Similar results were found in other studies [3, 9, 21, 22]. “Heat” is an important medical term in Traditional Chinese Medicine (TCM) and various ethnomedical systems in China [41]. It is a pathogenic syndrome in the human body and may lead to a range of human health problems such as influenza, fever, cough, dizziness, and lung abscess [42, 43]. To “clearing heat away and detoxifying” is critical and frequently terms in TCM, which is equally to prevent or treat heat-related symptoms, and to treat infections from viruses and bacteria or the poisoning caused by food, heavy metals, and pesticide. Ilex kudingcha, Gynostemma pentaphyllum, Hypericum japonicum, and Microcos paniculata were widely used as a Liáng chá (“cooling tea” or “cool tisane” in Chinese) in Southern China [21, 44,45,46,47]. Herbal tea consumption has been considered an important element of traditional medicine that focuses on preventive therapies and treating sub-health conditions through targeted dietary changes, mood management, and a work rest balance [48, 49]. Herbal tea-drinking habit plays an important role in traditional healthcare system in Guangxi. Forty-one herbal teas could improve blood circulation, thirty-three could be used for tonic, and six could aid digestion. Some studies have reported that herbal tea has great potential in preventing and treating chronic metabolic diseases [50,51,52,53,54,55,56].

Herbal tea is often consumed safely by people without any restriction on the dosage that has a long history [11]. Although few adverse events associating with the most frequently mentioned herbal teas were found in our investigation, caution should be taken as “natural” is not always good. Fu et al. reported that some herbal teas' overconsumption might cause negative effects [11]. Other studies also found that some phytochemicals in herbal tea are risky to humans [11, 57,58,59,60,61]. The content and quality of herbal tea products must be controlled under the related legal requirement throughout the supply chain from collection, transportation, processing, production, and storage. New technologies and methods, such as two-dimensional chromatography fingerprinting, molecular identification, and chemical detection, should be developed to detect chemical contaminants and adulterants of herbal tea plant species [62,63,64]. Policies and administrative management about herbal tea products and the formulation of their quality standard may ensure their manufacture following the legal requirements. Public awareness of potential safety issues associated with herbal tea products must also be improved through propaganda and education programs.

Local cultural differences could affect the choice of herbal tea plants

Herbal tea or cooling tea drinks are popular in Southern China and widely used for healthcare due to the damp humidity and heat levels of this area. Previous ethnobotanical studies have documented the plant materials and related traditional knowledge of herbal tea used in a few areas located in Southern China, such as Chaoshan [26], Fujian [27], and Taiwan [28]. In this study, a comparison of herbal tea between Guangxi and three neighboring areas (Chaoshan, Fujian, and Taiwan) was made. The results indicated that Guangxi has its own unique selection of herbal tea species. However, these compared four places have similar latitude ranges in geographical location (Fig. 5A) and hot/humid subtropical monsoon climate, which should result in similar natural environment conditions among these places. It means the natural environment is not the reason or at least the main reason for the unique choice of herbal tea plants by local people in Guangxi. Given this, the population composition and corresponding specific culture could be proposed as a crucial reason for the choice of herbal tea species.

As an autonomous region, Guangxi has the largest minority population in China. The Zhuang nationality accounts for 83.28% of minority population and 31.36% of the population in Guangxi [25]. In addition, the ethnic groups, including Yao (3.7%), Miao (1.1%), Dong (0.7%), Mulam (0.4%), and Maonan (0.17%), have sizable populations in Guangxi [25]. The Hakka, belonging to Han branch speaking Hakka dialects, has settled down in Chaoshan, Fujian, and Taiwan with a very considerable population [27, 29, 30]. Therefore, based on the above population composition of the compared places, the traditional knowledge of the main ethnic groups such as Zhuang, Yao, and Miao, and their culture on the use of plant resource could be one of the reasons for the differences in herbal tea species used compared to the other three areas, whose selection of herbal tea species may be affect by the traditional knowledge and culture from local communities. Importantly, it is necessary to further investigate how do the local culture affects the choice of herbal tea plants in the future.

Herbal tea is facing increasing opportunities and challenges

In urban areas of Guangxi, small stores run liáng chá was very popular here and there. The liáng chá industry has dramatically grown around Guangxi to meet regional, national, and global demand for herbal tea and dietary supplements for part reason of Guangxi government promotion [65]. This phenomenon is in line with the modern pursuit of health and dietary requirements. This active demand will certainly result in increased herbal tea. On the one hand, the sustainability of the herbal drinks' ethnomedicinal base is threatened with global environmental change, expanded commercialization, policies, and over-harvesting of natural resources. On the other hand, it promotes the cultivation of herbal tea plants to develop better and faster. For example, Camellia petelotii, as an herbal tea, has been listed as one of the most endangered species in China due to its natural population size [66]. Recent pharmacological studies revealed that this plant has good healthcare functions for its rich bioactive components [67]. In the past, it was not used extensively because of restrictions on wild natural resources, and the price was too high (the highest point reaching 30 000 CNY per kilogram) [68]. Advanced technology-based breeding and cultivation made C. petelotii becoming common in recent decades. Similarly, Gynostemma pentaphyllum, Ilex kudingcha, and Adinandra nitida have also begun industrialization for orientating markets on brand extensions.

Conclusions

This study conducted a comprehensive ethnobotanical investigation across Guangxi to document the plant species used as herbal tea, traditional knowledge of the herbal tea including used parts, preparation and treatments, and analysis of the cultural significance, health consistency, and special characteristics of Guangxi herbal tea. Our study recorded 155 herbal tea species in Guangxi. Most of these species were herbaceous plants, most commonly used part was leaf, and the main preparation method was decoction. Moreover, forty-one health benefits were reported from the recorded herbal tea and clearing heat away was the most common health-promoting effect. In total, 122 herbal tea species were only found in Guangxi compared to the herbal tea species reported in neighbored regions; among them, Siraitia grosvenorii, Plantago asiatica, Gynostemma pentaphyllum, Zingiber officinale, Pholidota chinensis, and Morus alba were the most cultural significance herbal tea species in Guangxi.

Our findings revealed that local people have rich traditional knowledge about herbal tea, which plays a vital role in their healthcare. These traditional knowledge and culture could affect the local people to select and use different herbal tea plants. The recorded herbal tea species in this study possess tremendous potential for local economic development in the future. Further research on efficacy evaluation and product development of herbal tea species is necessary.