Xixin (Asari Radix et Rhizoma), grows in the valleys of Mount Hua. It is now available everywhere, yet those produced elsewhere are not as authentic as those from Huazhou. Its roots are slender, and its taste is extremely pungent; hence it is named Xixin. The roots are harvested in February and August and dried in the shade for use. Nowadays, many people substitute it with Ducheng (Duhuo's look-alike). Ducheng is toxic to humans, so careful distinction is required when using it. In early spring, Ducheng sprouts from perennial roots; its leaves resemble a horse's hoof, standing three or two cun high; the stems are as thick as wheat stalks, with five to seven leaves, or eight to nine leaves per clump, without other branches or vines; purple flowers grow贴地 (close to the ground) on the reed heads within the gaps between leaf stems, appearing faintly visible; small fruits like beans form secretly, containing fragmented seeds resembling Tianxianzi (Hyoscyamus niger). Both seedlings and leaves are green and wither after frost. Its roots form clumps, resembling a rice brush in density, slender and four to five cun long, slightly yellowish-white, with a pungent taste. In the Jianghuai region, it is commonly called "Hati Xiang" (Hoof Fragrance). Because it is often mistakenly used, it is described in detail here.

Duhuo (Angelicae Pubescentis Radix) and Qianghuo (Notopterygii Rhizomatis et Radix) originate from the river valleys of Yongzhou or Longxi Nan'an. Those from Shu-Han are currently considered superior. Seedlings emerge in spring, with leaves resembling Qingma (green hemp); flowers bloom in clusters in June, varying in color from yellow to purple. When bearing fruit, plants with yellowing leaves grow among rocks, while those with green leaves grow in soil. This herb does not sway in the wind but moves spontaneously when there is no wind, thus also known as Duyao Cao (Swaying Grass). Roots are harvested in February and August and sun-dried for use. *Ben Jing* states that these two belong to the same category. Nowadays, people refer to the purple variety with dense nodes as Qianghuo, and the yellow variety forming blocks as Duhuo. Another view: Tao Hongjing noted that Duhuo grows in Yizhou, northern Sichuan, is slightly white in color, hollow and large in shape, and similar in usage to Qianghuo. Currently, there is a large Duhuo in Shu resembling Jiegeng (Platycodon root) but larger, with an odor completely unlike Qianghuo, possessing slight cold properties and few therapeutic effects. There is another Duhuo from Shu, resembling Qianghuo in shape, slightly yellow and very large. When harvested, it is cut into inch-length pieces and dried; its aroma is strong and fragrant, somewhat resembling Qianghuo, with an additional scent of Huaiye (Sophora leaf). It is widely used below the capital with excellent efficacy, leading one to believe this is the true Duhuo. However, market vendors sometimes select large Qianghuo as Duhuo, which is inappropriate. Generally, there are two types: those from Western Sichuan are yellow and fragrant like honey; those from Longxi are purple and called "Shanqian Duhuo" by Qin-Ling people. Ancient formulas used only Duhuo, whereas modern formulas use both Duhuo and Qianghuo, which is erroneous. *Qie Zhong Fang* treats stroke; upon initial detection, regardless of severity, phlegm-saliva must be induced to vomit first, followed by sequential treatment. For vomiting induction, use 5 da liang of Qianghuo, decocted in 1 da dou of water until reduced to 5 sheng. Strain the residue, add 0.5 sheng of good wine, mix with 0.5 sheng of stir-fried Niu Bang Zi (Arctii Fructus) sifted to fine powder. Adjust the dosage with the previous decoction and wine to induce vomiting. If the patient is already dizzy or unconscious, administer forcibly. Do not use purgatives or Miu acupuncture/moxibustion. Only treat with tonic soups, and recovery will occur naturally.