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The *Shennong Bencao Jing* (Divine Farmer's Materia Medica) did not distinguish between Bai Zhu (Atractylodis Rhizoma Alba) and Cang Zhu (Atractylodis Rhizoma), as their functions were originally identical. It was only from the Song and Yuan dynasties onwards that they began to be used separately. It is held that Bai Zhu has a bitter and sweet taste with a mild qi, tonifies the Middle Jiao (Middle Burner), eliminates dampness in the Spleen and Stomach, and is used to stop sweating. Cang Zhu has a bitter and pungent taste with a fierce qi, can ascend upwards, eliminate dampness in the upper body, and has a significant diaphoretic effect. Bai Zhu produced in Shexian, Anhui, is superior and should be stir-fried with soil from old walls. Cang Zhu produced in Maoshan, Jiangsu, is good and should be soaked in rice bran water and then roasted.

In the *Bencao Jing*, it was named Shuyu (Dioscoreae Hypoglaucae Rhizoma). The name was later changed to Shanyao (Chinese Yam) to avoid the imperial names of Emperor Daizong of Tang (Li Yu) and Emperor Yingzong of Song (Zhao Shu). The *Tang Bencao* states that those from the Shu Road are the best. Nowadays, only those produced in Huaiqing Prefecture are highly valued. However, varieties from other regions (referred to as "six places") are also quite excellent. People coming from Hebei say that boiling and eating yam there does not compare well with the produce from these six regions. In a local village, a poor family had a newborn lacking breast milk, suffering extreme exhaustion. Someone advised feeding the infant a porridge made of yam. By consuming only this food throughout, the child grew up healthy, fat, white-skinned, and disease-free, surpassing other children. Thus, the claim in the *Materia Medica* that it tonifies deficiency and emaciation is indeed evidenced. The *Bencao Gangmu* (Compendium of Materia Medica) records that wild varieties are suitable for medicinal use. Currently, yams from the "six places," when cooked, peeled, and processed, are white with a slight green tint and firm. Wild ones growing in mountains are even better. However, they are usually consumed merely as fruit or vegetables. If processed according to standard medicinal methods, their efficacy should not be inferior to those from Huaiqing. The *Bencao Gangmu* lists them in the Vegetable Section.

The *Bencao Jing* indicates its indications include heat stroke causing fever, inability to move the body, and various deficiencies such as tendon contraction and muscle nodules. Long-term consumption removes facial dark spots, improves complexion, adds luster, lightens the body, and prevents aging. The *Jieyao* (Explanation of Essentials) mainly relies on content from the *Mingyi Bielu* (Record of Famous Physicians). The *Bencao Gangmu* records that for treating various deficiencies, yam can replace Renshen (Ginseng Root), as it is neither cold nor dry, yielding great special effects. The *Jieyao* includes a formula containing Qiye (Toxicodendri Verniciflui Folium, Lacquer Tree Leaf) alongside Qingnian (Qingnian Grass, identity uncertain), which is Hua Tuo’s Qiye Qingnian San (Lacquer Leaf and Green Stick Powder). Qingnian grass is unrecognizable to people today; some say it is the true leaf of Huangjing (Polygonati Rhizoma), while others say it is Weirui (Polygonati Odorati Rhizoma). However, two elderly scholars in my hometown died after taking this formula sequentially. Some suggest that Qiye is actually the leaf of Wujia Pi (Acanthopanacis Cortex), known as Chaiqi in the *Bencao Jing*. A soldier in the locality suffered arm pain and could not draw a bow. Someone advised him to soak one jin (approx. 500g) of Weirui and four liang (approx. 200g) of Wujia Pi in wine and drink it. After finishing one jar, his health became vigorous, exceeding normal levels. Are ancient formulas really so effective? The *Bencao Gangmu* likely erroneously attached it under the Lacquer Tree. Lacquer itself is toxic. The claim in the *Bencao Jing* that long-term use lightens the body, and even the assertion in *Baopuzi* that it grants spiritual penetration and longevity, are hard to believe. The *Bencao Gangmu* attributes the toxicity to merchants mixing tung oil into lacquer, which is incorrect. I personally witnessed a lacquer harvester who accidentally spilled lacquer all over his body, resulting in incurable sores. How much more dangerous would ingestion be? Tao Hongjing correctly stated that raw lacquer is intensely toxic. Ancient texts did not use lacquer leaves, hence their flavor and aroma are missing. The *Bencao Gangmu* likely speculated on its therapeutic indications based on ancient formulas.