Common Duckweed refers to the dried whole herb of Spirodela polyrrhiza (L.) Schleid., a perennial aquatic plant in the Lemnaceae family. It is produced throughout China and harvested in the summer. After harvesting, it is sun-dried and used in its raw form.
Properties & Meridians
Taste: Pungent
Nature: Cold
Meridians: Lung, Bladder
Functions
- Induces sweating and relieves exterior symptoms
- Promotes the eruption of measles and relieves itching
- Promotes urination and reduces swelling
Clinical Applications
- Used for wind-heat invasion with fever and no sweating.
- Treats incomplete eruption of measles and itching from wind rashes.
- Used for edema and urinary retention.
Usage & Dosage
Decoction: 3–10g
- External use: appropriate amount.
Precautions
Avoid use in cases of exterior deficiency with spontaneous sweating.