Resina Liquidambaris — Liquidambar formosana Hance (family Altingiaceae), the resin exuded from the trunk; also known in the trade by the older name 白胶香
Nature and flavour. Acrid and slightly bitter, neutral. Liver and Lung systems.
A tree resin rather than a plant part, and the only item in this batch whose classical record is mostly external. The sources credit it with quickening the blood and relieving pain, staunching bleeding, resolving toxin and helping flesh to generate, and it is recorded for knocks, falls and painful swellings, for sores, abscesses and insect bites, and less commonly for bleeding from the nose or mouth in the traditional description. It is applied to the skin on its own or in plasters and salves, and it is a standard ingredient of the compound plasters and trauma liniments of Chinese pharmacy. The internal record exists in the classical sources but is small next to the external one. The traditional uses are recorded; the modern clinical evidence for them is limited and is not established.
性味归经。辛、微苦，平。归肝、肺经。
这是树脂而非植体部位，也是本批中古典记载以外用为主的一味。古籍谓其活血止痛、止血、解毒生肌；记载用于跌扑损伤与肿痛，疮疡、痈肿与虫咬，较少见地亦载其治传统所称的鼻衄、咯血。多单用或入膏药、软膏外敷，是中药房复方膏药与跌打搽剂中的常备成分。内服记载在古籍中存在，但与外用相比分量很小。上述传统用途有文献记载，其现代临床证据有限，尚未被证实。
这一味应当先当作外用品看待。外敷时它是苏合香、香脂类的树脂，而这一类树脂在皮肤科是公认的接触性致敏原 —— 苏合香本身即列入标准斑贴试验系列 —— 因此贴敷处出现发红、瘙痒或皮疹扩散，是揭掉停用、而不是继续贴的理由。破损皮肤、已感染的创面与烧伤，未经专业指导不得使用。内服方面它绝不属于厨房之物：活血类树脂的古典禁忌一律适用，孕期与哺乳期禁用，且吞服本品并无已确立的现代证据支持。此类树脂在流通中名称重叠，既易掺伪、也易与其它芳香树脂混淆；鉴定依据是拉丁名与供应商，而不是袋上的一个中文名。因其黏而芳香，应远离儿童与眼睛。任何使用都须在合格执业者监督下进行；本页刻意不回答「该用多少」。