Plant leaves for wrapping zongzi in China: an ethnobotanical study

BACKGROUND: Zongzi, a common Chinese rice-pudding and one of the most symbolic foods in traditional Chinese festivals, is integral to both Chinese traditional culture and daily meals. Traditionally, the leaves of different plant species have been used to wrap zongzi. The variety of zongzi leaves (ZLs) can contribute to the zongzi-based cultural diversity. Given the cultural and dietary significance of zongzi, the ethnobotanical surveys were carried out, aiming to investigate the diversity of plant species and associated traditional botanical knowledge of ZLs, which could attract particular attention for their further studies. METHOD: Both literature studies and field surveys were conducted in the study. The field investigations were carried out from May 2006 to June 2018 throughout China. Ethnobotanical information about ZLs was obtained by direct observation, semi-structured interviews, and key informant interviews. RESULTS: In total, ZLs from 57 plant species were identified and recorded, belonging to 38 genera and 18 families. Several folk legends have been formed to explain the origin of using plant leaves to pack zongzi. Over time, Chinese people have developed diverse traditional botanical knowledge surrounding ZLs, especially regarding the zongzi flavor, antiseptic functions, and medicinal values. Based on the literature review, some species of ZLs such as the leaves of Corchorus capsularis and Vernicia fordii may even pose a potential threat to human health. Presently, in some regions of China, the traditional ZLs, such as Cocos nucifera, Tilia tuan, and Zizania latifolia, are being substituted by commercialized ZLs such as Phragmites australis and Indocalamus tessellatus. CONCLUSION: A variety of traditional ZLs have been discovered in China. Although diverse traditional knowledge exists in China surrounding the usage of ZLs, some species may have the potential of threatening human health. Therefore, further explorations are necessary to comprehensively evaluate traditional ZLs, the results of which could help to conserve the cultural diversity of zongzi, to guarantee food safety, and to encourage the uses of plant leaves in food, medicine, and environmental management, for our human health.