Knotgrass

the herb of knotgrass (Polygoni herba)

Knotgrass (Polygonum aviculare) is a low, spreading annual with small leaves and inconspicuous flowers in the leaf axils; it stands being walked on and grows exactly where the ground is trodden down, beside paths, in yards and in cracks in paving.

The flowering herb is gathered from June to September, without the root; it is cut with shears, because the stems are tough. It is dried in the shade, in a thin layer.

Because it grows on paths and in yards, the place matters most when gathering: never beside roads, in car parks or where animals are kept. The plant is rich in silica, much like horsetail.

Use and evidence

The EMA recognises traditional use to increase the amount of urine in minor urinary complaints and as a help in mild inflammation of the mouth or throat; the other broad claims have not been retained. EMA 1, EMA 2.