Library

[Water Fern / Duckweed] (Spirodela polyrhiza)
Taste: Acrid, Sour. Nature: Cold. Toxicity: Non-toxic. It originates from willow catkins flying with the wind, entering ponds and marshes, and generating life through water absorption. The smaller varieties have green surfaces and backs; the larger ones have green surfaces and purple backs. They lack roots below and float on the water surface. For medicinal use in treating Wind-Stroke (Zhong Feng, stroke characterized by facial paralysis), only duckweed is suitable. Harvested around the 15th day of the seventh lunar month, it is dried according to standard procedures. Spread out on a bamboo sieve supported by a water basin. Exposed to intense sunlight until completely dry. (If the basin lacks water, drying will not occur.) Pulverized into fine powder and sifted. Formed into pills the size of bean shots using honey. Administered with Doulin wine (wine poured over roasted soybeans), swallowed at once on an empty stomach. It induces rapid sweating and quickly dispels Wind pathogens. It also treats epidemic febrile diseases and can be used for bathing to relieve generalized pruritic sores. (Freshly harvested, decocted for external wash.) It reduces edema, promotes urination, eliminates acute dryness, and stops thirst. When mosquitoes are abundant on summer nights, burning its smoke can repel them.

(Chen Jiamo) Commentary: The *Puji Fang* (General Holy Prescriptions) entry for Dafeng Dan states: During the excavation of rivers in Tokyo (Bianjing), a stone stele was unearthed bearing Sanskrit celestial script, which no one could decipher. Lin Lingsu interpreted it character by character, revealing it to be a prescription for treating Wind-Stroke. The verse reads: "Heaven-born spiritual herb, rootless and stemless, neither in mountains nor on shores. Initially driven by east winds like flying catkins, floating green stems drift on the water surface. One divine ingredient removes deep ailments, harvest must be on the fifteenth of the seventh month. Fear not flaccid paralysis or stroke, three pills taken with wine induce profuse sweating."

[Euphorbia pekinensis / Chinese Spurge Root] (Da Ji)
Taste: Acrid, Sweet. Nature: Greatly Cold. Yin within slightly Yang. Toxicity: Slightly toxic. It is cheaply cultivated and grows everywhere. Red shoots emerge in spring, growing densely day by day. For medicinal use, only the main root is harvested. Side roots mistakenly included in decoctions cause unbearable cold diarrhea. It is incompatible with Dioscorea hypoglauca (Shuyu), compatible with Vigna angularis (Chidou). It is antagonistic to Glycyrrhiza uralensis (Gancao), Sargassum fusiforme (Haizao), and Genkwa flos (Yuanhua); it fears Acorus tatarinowii (Changpu), Phragmites communis rhizome (Lugen), and Rattus rattus feces (Shushi). Often used together with Kansui Radix (Gansui) to promote urination. It reduces edema, abdominal distension, and acute pain; eliminates skin dryness and pain caused by Wind-Stroke. It expels Gu toxicity, breaks up hard masses (Zhengjian). It regulates menstruation, induces abortion, dissipates neck goiters, and drives out blood stasis. The young plant is named Zeqi, with a bitter and acrid taste. It clears pathogenic heat from the skin and resolves edema of the face and eyes. It rapidly dispels abdominal water qi and supports deficient Yin qi.