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The flavor is pungent and warm, with great toxicity. It treats wind-stroke (Zhong Feng), aversion to wind accompanied by shivering sweating, eliminates cold-dampness bi-syndrome (Bi Zheng), rebellious cough and upward rushing of qi, and breaks up accumulations of cold and heat. Its juice, when boiled, is called She Wang (Poisonous Arrow Paste), used to kill birds and beasts. (Attached from *Bie Lu*.)

(*Shen Nong Ben Cao Jing* names it Wu Tou; *Bie Lu* names it Wu Hui; currently known as Cao Wu, which is the wild variety of Wu Tou, found everywhere. Its root is black on the outside and white on the inside, wrinkled and dry. Its nature is highly toxic, more intense than Chuan Wu, and cannot be used indiscriminately as mentioned in Jie Gu's previous remarks.)

(Cao Wu Tou is now often planted in courtyards by people in Hangzhou. It blooms in September with pale purple, delicate flowers, appearing at the same time as chrysanthemums, hence called Ying Ge Ju (Parrot Pigeon Chrysanthemum) or Shuang Luan Ju (Double Phoenix Chrysanthemum), named after its floral shape. The root has great toxicity, significantly different from that produced in Sichuan. In ancient times, it was sometimes called Wu Tou and sometimes Wu Hui, with no distinction made based on the era. Later generations distinguished them by shape: those with a regular shape resembling a crow's head were called Wu Tou; those with two branches merging together resembling a crow's beak were called Wu Hui. Although their shapes differ, their therapeutic effects are identical, so strict distinction is not necessary. Yin An classified Wu Tou as belonging to Chuan Wu and Wu Hui as belonging to Cao Wu, likely fearing that later generations might confuse the terms and use them incorrectly, potentially causing harm. Although this is a forced distinction, his intention greatly benefits the world and future generations.)

Although Wu Hui is also called Wu Tou, it is essentially Tu Fu Zi (Local Aconite). Its nature is inferior and toxic; it can only search out wind and overcome dampness, open stubborn phlegm, break hard accumulations, and treat stubborn sores by using toxicity to combat toxicity. It cannot, like Fu Zi, augment the superficial yang of the Taiyang channel, assist the fire-heat of the Shaoyang channel, and facilitate the circular rotation of Shen Ji (Spirit Mechanism). Users must distinguish between them carefully.

(The toxicity of Cao Wu exceeds that of Chuan Wu. This is because Chuan Wu is cultivated by human effort and harvested at the appropriate time, whereas Cao Wu grows wild above ground and ages over many years, making its energy particularly fierce. This is analogous to taro: cultivated taro is non-toxic and edible, while wild taro is toxic and inedible; the principle is the same. Furthermore, Chuan Wu is first salted to reduce its harshness, then shipped long distances, taking time, thus slightly reducing its toxicity. Cao Wu is unprocessed by salting and may be freshly harvested for immediate use, resulting in greater toxicity. Lu Bu Yuan stated: Human diseases include four types—Bi (obstruction), Feng (wind), Wei (atrophy/withering), and Jue (reversal/cold limbs). Cao Wu's power only宣 (disseminates/opens) Bi and Feng. Yang Qi movement has four aspects: ascending, descending, exiting, and entering. Cao Wu's power operates only through ascending and exiting. However, Yang Qi tends to act independently and exclusively engages in killing activities. Like a stubborn person who should be avoided, one must exercise caution. Collecting Wu Tou, crushing it to extract juice, and boiling it produces She Wang. Hunters apply it to arrowheads to shoot birds and beasts; those hit die instantly. If it hits a human, death is also instant. *Ri Hua Ben Cao* states: For poisoning by She Wang, any one of the following can detoxify: Gan Cao (Licorice Root), Lan Zhi (Indigo Juice), Xiao Dou Ye (Vigna Seed Leaf), Fu Ping (Duckweed), Leng Shui (Cold Water), or Ji Cai (Shepherd's Purse). Using just one of these alone is sufficient to counteract it.)