「土茯苓」一名首見於明代醫籍《續醫說》。它因16世紀初流行的新疾楊梅瘡而聲名鵲起，一度成為風靡世界的驅梅要藥。本文旨在探討這一初時名不見經傳的草藥，如何伴隨新疾的流播而漸得要藥之譽。大致而言，土茯苓的知識書寫經歷了三個階段：最初為南方平澤的禹餘糧；後出現俗名萆薢，二者同物異名；再至楊梅瘡要藥、正名土茯苓。掌握知識話語權的主流醫家或知識菁英，與普通醫家或擅通醫藥者，共同參與了其文本知識書寫的歷程。主流醫家構成了土茯苓知識的核心敘述，並在肯定知識的準確性中發揮關鍵性作用。權威的庇佑使土茯苓知識生產與傳播歷程中獲得認同與信賴，也在一定程度上保證了醫藥知識演化的穩定性和延續性。然而，本草知識的構建無法單獨依賴某些人物或理論，仍需注意到游離於菁英之外的「少數者」。儘管這些醫家或因名望所限，未能留存更多訊息，但也正因這樣一個敢於挑戰主流醫學知識群體的存在，才得以在某種意義上緩解知識權威造成的僵化威脅。本文行文雖止於清代，但同一物種如何為不同異文化人群所書寫的命題，仍值得進一步關注。

The term Tufuling (often referred to as Smilax glabra) was first described in an ancient Chinese medical book, Xuyishuo, from the Ming dynasty. It quickly gained renown for use in treating the outbreak of syphilis in the early 16th century, a new disease at that time. This present article endeavors to discuss how an unknown herb ultimately became widely known as a valuable medicine for fighting the spread of a new disease. This process occurred in three stages: Initially, a plant called Yuyuliang grew in the southern marsh, this is considered the earliest historical reference to Tufuling. Later, it was considered to be a herb of the same type as Bixie (often referred to as Rhizoma Dioscoreae Septemlobae) but called a different name. It finally appeared in ancient Chinese medical books under its standardized name Tufuling, identified as an essential syphilis medicine. The intellectual elite and ordinary people alike played their respective roles and missions in the production and diffusion of knowledge about Tufuling. The former undoubtedly established the core narrative of knowledge related to Tufuling and played an important part in affirming the accuracy of this knowledge. Authoritative support has ensured greater recognition and trust in the production and dissemination process of knowledge concerning Tufuling, which ensures the stability and continuity of the evolution of medical knowledge to a certain extent. However, herbal knowledge cannot be solely reliant on specific individuals or theories, and the “minority” who are detached from the elites must not be forgotten. Although these practitioners may have provided less information due to their limited renown, it is the existence of this group who dared to challenge mainstream medical perspectives that helped counter the increasing threat of knowledge authority. Although this article only covers the evolution of knowledge related to Tufuling to the end of the Qing dynasty, the question how an intercultural population has written about the same herb species merits further attention.