Lemna, Duckweed, Fu Ping 浮萍

Lens palustris, Lens lacustris, L. aquatica, Muscus palustris
Fu Ping (TCM)
Gart der Gesundheit, Cuba, 1485
Ortus Sanitatis, Meydenbach, 1491
Krauterbuch, Lonitzer, 1578

Kreutterbuch, Matthiolus, 1586

4 different varieties of Duckweed (Lemna)
Lindman, Bilder ur Nordens Flora, vol. 2 (1922-1926)

Botanical name:
Lemna spp., including L. minor
There are a number of types of Duckweed
TCM uses the related Spirodela polyrrhiza and others,
and in some parts, Lemna species (incl. L. minor) are used.

Parts used:
Dried herb

Temperature & Taste:
Cool, dry. Pungent

Classifications:
A. Clear Exterior Wind-Heat
L. minor
Flora von Deutschland, Kohler, 1886

Uses:
1. Clears Wind-Heat, Promotes Sweat:
-acute wind-heat cold / flu with fever, headache, body aches (TCM)
-acute Heat diseases and Fevers (Lonicerus)
-Rhinitis, Pharyngitis

2. Clears Heat, Promotes the Expression of Rashes
-promotes expression of Rashes such as Measles (Chinese Pharmacopoeia)
-wind-heat Itching

3. Clears Heat, Promotes Urine:
-Edema with Oliguria (Chinese Pharmacopoeia)
-mostly used for Acute Wind-Heat conditions with Edema

4. Externally:
-applied to hot inflammations and tumors (Lonicerus)
-'applied on acute gout and painful arthralgia'. (Avicenna)
-Boils, Carbuncles
-Nasal Polyps
-Acute Swellings, Erysipelas and Herpes (Avicenna)
-'when used with old olive oil, softens aud soothes the Nerves'. (Avicenna)
-as a palster, applied to Hernia (Avicenna)
-burned to drive away Mosquitoes. (Bensky)


Dose:
It can be taken as a solo medicine to clear Heat and promote Sweat.
Decoction: 3–9 grams (up to 30 grams), added towards the end of decocting
Powder: 1–3 grams

Comment:
1. This is an especially effective cooling herb to promote Sweating. Ancient TCM practitioners claimed it more effective than Ephedra Ma Huang to promote sweat.
2. Ashes contain iodine and bromine.

Main Combinations:
1. Acute Wind-Heat cold or flu:
i. Duckweed with Schizonepeta Jing Jie, Peppermint (Bo He), Forsythia Lian Qiao
ii. Duckweed with Peppermint (Bo He), Cicada slough (Chan Tui), Forsythia Lian Qiao
2. Beginning stages of Measles or other Eruptive Fevers:
i. Duckweed with Peppermint (Bo He), Burdock seed (Niu Bang Zi)
ii. Duckweed with Peppermint (Bo He), Cicada slough (Chan Tui),
3. Itching Rashes: Duckweed with Peppermint (Bo He), Burdock seed (Niu Bang Zi), Sophora Ku Shen

Cautions:
1. Not used in deficient conditions, especially with spontaneous sweating. In general, it is not used in cases with sweating.

Main Preparations used:
Distilled Water