Library

Sweet, neutral, non-toxic. It is a herb for the Foot-Shaoyin and Hand-Jueyin meridians. When used raw, its nature is slippery; it promotes blood circulation, resolves stasis, unblocks the meridians, facilitates urination, expels cold and heat pathogens in the heart, abdomen, and bladder, and treats injuries from falls and blows, as well as swelling from sores and boils. When stir-fried until blackened, its nature becomes astringent; it stops all types of vomiting, epistaxis, metrorrhagia, leukorrhea, hematochezia, and dysenteric blood. Decoction stops seminal emission.

It grows everywhere, but those from Taizhou are considered superior. When the tender leaves first emerge from the water, they are red and white. In summer, stems shoot up among the dense leaves, with flowers clustered at the stem tips like clubs; this is commonly known as "Pubang" (cattail flower spike), which refers to the pollen/dust within the flowers.

For pain due to blood and qi stagnation in the heart and abdomen, take together with powder of Datongcao (Lingzhi). (Verified Formula 1.)
For tongue swelling filling the mouth, apply as powder. Alternatively, mix with powder of Ganjiang (Dried Ginger) and apply. (Formula 2.)
For double tongue with sores, apply powder topically. (Formula 3.)
For epistaxis, take with Qingdai (Indigo Naturalis) and fresh boiled water. (Formula 4.)
For hematemesis and spitting blood, take two liang, three qian each time with cool boiled water. (Formula 5.)
If hematemesis persists, take as powder with Shengdi Tang (Rehmannia Root Decoction). (Formula 6.)
For hematuria. Same as above. (Formula 7.)
For bleeding from metal wounds, take regularly. (Formula 8.)
For fetal restlessness threatening premature labor, take with Jinghua Water (first-drawn well water). If the pulse is scattered, urgently add Renshen (Ginseng). (Formula 9.)
For retention of the placenta. Same as above. (Formula 10.)
For postpartum blood stasis, decoct three liang in water. (Formula 11.)
For Erzhen Xuejia (postpartum abdominal mass due to blood stasis), take with rice soup. (Formula 12.)
For postpartional irritability and oppression, take with flowing stream water. (Formula 13.)
For internal stasis from falls and blunt trauma, take with wine. (Formula 14.)
For dampness and itching in the genital area, apply as powder; four applications yield good results. (Formula 15.)
For otorrhea (pus discharge from ear), sprinkle powder into the ear. (Formula 16.)
For bleeding from the ear, use stir-fried blackened powder and sprinkle. (Formula 17.)
For severe bleeding from mouth and ears, urgently bind both breasts with cloth, and decoct together with Ejiao (Donkey-hide Gelatin) and Shengdi (Rehmannia Root) for oral administration. (Formula 18.)

This refers to the small duckweed found in water, not the large Spirodela.
Pungent, sour, non-toxic. Enters the Hand-Taiyin Lung Meridian. It clears skin heat and releases the exterior, eliminates urticaria and dispels wind, drains fluid retention and facilitates urination, stops itching and relieves thirst associated with Xiao Ke (Wasting-Thirst syndrome), and treats paralysis and palsy, as well as injuries from falls and blows causing hematemesis.

It grows in ponds and marshes everywhere. It sprouts in spring; some say it transforms from willow catkins. One leaf overnight multiplies into several leaves; fine roots grow beneath the leaves, which constitute its root system.
One variety has green surfaces on both sides. Another variety has a green upper surface and a purple-red lower surface resembling blood; this is called Zibei Fuping (Purple-backed Duckweed), which is superior for medicinal use. Harvest in July, place in a sieve, set the sieve over a large basin of water, and it dries easily.