Common Knotgrass Herb

Naming

Bian Xu (Herba Polygoni Avicularis)——Shen Nong Ben Cao Jing (Shen Nong’s Herbal)

The Processing of Common Knotgrass Herb

Origin

The aerial part of annual herbaceous plant Polygonum aviculare L. of family Dolygonaceae.

Location

Most areas in China.

Harvest

Collected in summer.

The true smell and taste

No smell, slightly bitter.

Best quality

Green, profuse leaves, tender, without impurity.

Processing

Sliced and unprocessed.

The Effect of Common Knotgrass Herb

Property

Bitter, slightly cold; bladder meridian entered.

Actions

Induce diuresis to treat stranguria, remove dampness.

Indications

A. Stranguria

It is good at clearing damp-heat in lower-energizer, and inducing diuresis to treat stranguria. It is usually indicated for urolithic stranguria and heat stranguria, such as with Mu Tong, Qu Mai and Che Qian Zi in Ba Zheng San from Tai Ping Hui Min He Ji J u Fang. For blood stranguria, it should be combined with blood-heat-clearing and bleeding-stopping herbs, such as Da Ji, Xiao Ji and Bai Mao Gen.

B. Eczema and vulvae pruritus, damp-heat jaundice

It has the action of removing damp-heat to relieve itching and is indicated for vulva pruritus and eczema, damp-sore due to damp-heat accumulation in lower-energizer. It could be used singly or decocted with Di Fu Zi, She Chuang Zi and Jing Jie, etc., for external washing. It is also indicated for jaundice of damp-heat type with its action of clearing damp-heat. It should be combined with the dampness-drying and jaundice-treating herbs such as Yin Chen Hao and Zhi Zi, etc.

Dosage and Administrations

Decoct 9~15g. Double the dosage when use the raw one. Proper dosage is for external application.