Description: The common name of this native annual aquatic or waterside species refers to the biting peppery taste of the leaves when chewed. It is a rather uninteresting-looking plant up to about 2 ft (60 cm) tall (often less), with narrow leaves and a slender, drooping spike of green flowers. The flowers and the stalk of the spike carry small glands.

It is very common beside lakes, ponds, rivers and canals. A robust variety (var. densiflorum) grows in arable fields as a weed, especially in potato crops: it is very rare or perhaps overlooked.

Polygonum hydropiper is an alternative name.

All names: Persicaria hydropiper (L.) Spach; Polygonum hydropiper L.

Distribution Map from NBN: Persicaria hydropiper at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Persicaria hydropiper at iNaturalist World Species Observations database.