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Duheng, ancient records do not specify its place of origin; it is now found throughout the Jianghuai region. Its seedlings and leaves resemble those of Asari Radix et Rhizoma (Xixin), differing only slightly in aroma, while its root is also thicker, yellowish-white in color. The leaves resemble a horse's hoof, hence the name "Horse Hoof Fragrance" (Mati Xiang). The roots are harvested on the third day of the third lunar month, thoroughly washed, and sun-dried. According to the *Classic of Mountains and Seas* (*Shan Hai Jing*), there is a grass on Mount Tiandi that resembles Malva verticillata (Kuicai) in shape and smells like Pogostemon cablin (Miwu); it is called Duheng. Wearing it allows one to run as fast as a horse, and consuming it cures goiter (Ying). Guo Pu's commentary states: "Wearing it enables one to run swiftly." Another view holds that horses become stronger and faster after ingesting it. The *Erya* refers to it as "Du," also known as "Tulu." However, since Du Ruo is also sometimes called Duheng, some suspect they are the same. Based on Guo Pu's note that it resembles Kuicai and is fragrant, we know this is indeed Duheng. Currently, people use it for bathing water and as clothing fragrance, which is very effective.

Zicao, grows in the valleys of Dangshan and the Chu region, and is now ubiquitous. It is sometimes cultivated in household gardens. Its root is used for dyeing purple. The *Erya* calls it "Miao," and the *Guangya* calls it "Ci." The seedlings resemble Patchouli (Lanxiang); the stem is red, and the nodes are green. It flowers in February with purple-and-white blooms and bears white fruit in autumn. The roots are harvested in March and dried in the shade. It is rarely seen in ancient prescriptions. Modern physicians frequently use it to treat Cold Damage (Shanghan) and epidemic diseases, specifically to promote the eruption of sores and rashes that fail to surface. In Wei Zhou's *Single-Action Prescriptions* (*Duxing Fang*), it is prescribed for smallpox-like eruptions (Wandou Chuang) by boiling Zicao into a decoction for drinking. Later generations adopted this method, finding the efficacy particularly rapid.

Ziwan, grows in the valleys of Fangling, as well as in Zhending and Handan. It is currently found in Yaozhou, Chengzhou, Sizhou, Shouzhou, Taizhou, Mengzhou, and Xingguo Jun. Seedlings and leaves emerge close to the ground in March, with three or four leaves connected together. Yellow-purple and white flowers bloom in May and June, producing black seeds. The root possesses white hairs and is very soft and fine. Roots are harvested in February and March and dried in the shade. There is another variety that is white, named Baiwan. Su Gong stated: "Baiwan is equivalent to Nüwan, and their therapeutic properties are identical." When Ziwan is unavailable, Nüwan can be used interchangeably. Relevant details follow in subsequent entries. It is rarely used nowadays. However, it is considered essential in the ancient and modern *Chuanxin Fang*. For treating chronic coughs that do not resolve, this prescription is excellent. Remove the rhizome head from 1 liang of Asters Tataricus Root (Ziwan) and 1 liang of Winter Flower Bud (Kuandonghua), along with 0.5 liang of Stemona Root (Baibu). Pound and sieve these three substances into a powder. Take 3 qianbi per dose. Decoct with 3 slices of Fresh Ginger (Shengjiang) and 1 Smoked Plum (Wumei), mix with the decoction, and take one dose before sleep after meals.