Plant diversity in herbal tea and its traditional knowledge in Qingtian County, Zhejiang Province, China

Herbal teas composed of locally occurring plant species have long been used as the primary form of health care in Qingtian County, Zhejiang Province, China. However, large-scale emigration overseas and an aging population threaten the conservation of traditional knowledge of these herbal teas. Traditional knowledge about the plants used for these herbal teas is not well documented in Qingtian, despite their widespread use. The aim of this study was to assess the plant-cultural diversity of plants used as herbal teas, and to point out the prospective value of herbal teas used by Qingtian people. This study was conducted using semi-structured interviews, as well as field and market surveys. Forty-three local informants were interviewed. We recorded plant resources, plant parts used, local names, and medicinal uses. Quantitative ethnobotanical indices, including cognitive salience (CS), frequency of citation (FC), index of informant consensus (F_ic) and use value (UV), were calculated to analyze the level of representativeness and relative importance of plants used in herbal teas. One hundred and twenty-nine species belonging to 75 families and 113 genera were reported to be used in herbal tea, with Compositae being the richest family. Whole plants are most commonly used to make herbal teas (66.7%). In this study, informants reported that 92.2% of plant species used in herbal teas are wild. The most utilized herbal preparation form is dry/fresh. Informants reported that herbal teas are used to treat 31 ailments. Our results show that the highest representativeness, based on CS and FC, was recorded for species Actinidia eriantha. Based on UV, the top five most used species are Goodyera schlechtendaliana, Plantago asiatica, Prunella vulgaris, Lophatherum gracile and Leonurus japonicus. The highest F_ic was cited for dental medicine. This study helps document the status of current herbal teas in Qingtian. The use value and traditional knowledge of herbal teas have provided basic data for further research focused on bioactivity studies and sustainable utilization of the most important species.