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According to the *Bencao* (Materia Medica), the first character offended the temple name of Emperor Yingzong. The second character was "Yu" (Dioscorea). Because Tang Daizong's personal name was Yu, the second character was changed to "Yao", and people today call it Shanyao (Chinese Yam). In this way, the original name is completely lost. Fearing that after many years people might mistake Shanyao for a different substance, this is recorded here. This medicinal material is best when dried while fresh, which makes it suitable for use in decoctions. Its processing method: In winter, wrap hands in cloth, use a bamboo knife to scrape off the skin, place it in a bamboo sieve under the eaves in a ventilated area, avoiding direct sunlight. It dries by half in one night; wait until fully dry before storing. Drying is faster only when the wind is strong. The reason for using the dried product is that the fresh product is moist and slippery, making it unsuitable for medicine; if cooked, it can only be eaten and may stagnate Qi. The rest follows the classics.

In recent times, there are more than twenty varieties. Only those with single leaves, small yellow flowers, dark green small and thin leaves, and blooming according to the season are authentic. These are what the *Yueling* (Monthly Ordinances) refers to as chrysanthemums with yellow flowers. Additionally, white chrysanthemums from Dengzhou with single leaves can also be used in medicine, but other medical texts do not employ them. They specifically treat wind-heat affecting the head and eyes. Nowadays, many people collect them to make pillows.

The branches and leaves resemble those of the locust tree, growing five or six chi tall, but the leaf tips are slightly pointed and rough/rough-skinned, appearing to have white hairs. The fruits grow in pods, resembling acacia pods, growing on a single stem. The seeds are like small flat beans, unbreakable by teeth. Currently produced at the borders of Hedong and Hexi, they must be lightly roasted before use in medicine; otherwise, their nature is slightly cool. Raw usage tastes poor.

Those currently in use are all obtained through trade at the Hebei border markets (Quechang), originating entirely from Goryeo. They are generally hollow, soft, and tasteless, unlike those from Shangdang in Luzhou, which have rich flavor and solid texture, providing reliable efficacy. Locals who obtain a plant place it on a board, binding it with colored silk threads. The roots are quite slender and long, differing from those at the border markets. Roots hanging down may exceed one chi in length, or have ten branches. Their price equals that of silver, making them somewhat rare.

Fine as small grass, three or four cun long, flexible and tough. When broken, the cross-section resembles meat yet is solid. Nowadays, many people mix Mu Hu (Wood Dendrobium) indiscriminately, and even physicians cannot clearly distinguish them. The world also calls it Jin Chai Shihu (Gold-Hairpin Dendrobium), likely a metaphorical term coined by later generations. However, this is inappropriate. If Wood Dendrobium is broken, the center is hollow, resembling grain stalks, over a chi long, merely possessing a deep yellow lustrous color. True Shihu (Dendrobium officinale) has merit in treating deficiency-heat in the stomach.