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Duheng (Asarum forbesii)

Pungent, warm, non-toxic. Primarily treats wind-cold cough and rebellious qi. Imparts fragrance to the body and clothing. Grows in mountain valleys. The roots are harvested on the third day of the third lunar month, thoroughly washed, and dried in the sun.

Tao Hongjing stated: The roots and leaves resemble Xixin (Asari Radix et Rhizoma), differing only slightly in odor. It is found everywhere. It is rarely used in medical prescriptions, but is consumed by Daoists. It causes the body and garments to become fragrant. The *Classic of Mountains and Seas* (*Shan Hai Jing*) states that it can treat ying (goiter). The *Tang Bencao* commentary notes: Duheng's leaves resemble those of kui (mallow), shaped like a horse's hoof, hence the common name "Horse Hoof Fragrance" (Matixiang). It grows on the shady side of mountains and in damp, low-lying areas near water. Its root resembles Xixin and Baiqian (Caulis Bupleuri). Currently, people often substitute it with Ji (Arisaema consanguineum), which is erroneous. Ji has a single stem with four leaves at the tip and white flowers between the leaves; it lacks any aromatic scent entirely. It is toxic and induces vomiting if ingested; it is only useful for treating sores and scabies, and must not be confused with Duheng. Minister Yuxi and others carefully note according to the *Erya*: "Du" refers to Tulü. The annotation states: This is Duheng. It resembles kui and is fragrant. The *Shan Hai Jing* says: On Tiandi Mountain, there is a herb resembling kui, with an odor like Miwu (Angelica dahurica), named Duheng. It enables horses to run fast, and consuming it cures goiter. Guo Pu's annotation states: Wearing it allows one to ride horses efficiently. Some say: Horses that consume it run vigorously. The *Yaoxing Lun* states: Duheng serves as a guiding drug. It can stop wheezing and panting caused by rebellious qi, resolve phlegm-fluids, break up stagnant blood, and primarily treat tumors and goiters in the neck region.

The *Tu Jing* states: Duheng was not previously recorded regarding its place of origin; currently, it is found throughout the Jianghuai region. The seedlings and leaves resemble Xixin, differing only slightly in aroma, while the root is also thicker, yellowish-white, and the leaves resemble horse hooves, thus named Matixiang. The roots are harvested on the third day of the third lunar month, thoroughly washed, and dried in the sun. Carefully noting the *Shan Hai Jing*: On the Mountain of the Heavenly Emperor, there is a herb resembling kui, with an odor like Miwu, named Duheng, which enables horses to run fast, and eating it cures goiter. Guo Pu's annotation states: Wearing it allows one to ride horses, or some say: Horses that obtain it run vigorously. The *Erya* calls it Du, also known as Tulü. However, Duruo is also called Duhen, leading some to suspect it might be Duruo. Based on Guo Pu's annotation stating it resembles kui and is fragrant, we know this is indeed Duheng. Currently, people use it for bathing decoctions and for perfuming clothes, which is excellent.

The *Yanyi* states: For Duheng, the root is used. It resembles Xixin, but the root color is white, and the leaves resemble the underside of a horse's hoof. Merchants often confuse it with Xixin; one must distinguish them thus. The *Erya* correctly identifies it as resembling kui and being fragrant. Comparing Duheng with Xixin reveals their authenticity. Moreover, Xixin from Huazhou is of superior quality. Duheng is yellowish-white, curled and brittle, forming clumps when dry.