Persicaria hydropiper (L.) Delarbre

An annual herb. The stems are erect and curve upwards. It can be 80-100 cm tall. The stem has many branches. It forms roots at the nodes. The nodes are enlarged and they have a red ring at the base. The leaves are alternate and narrowly sword shaped. They have glands. The leaves narrow towards their base. The leaves have a peppery taste when chewed. There is a stipule or leaf like structures at the base of the leaf stalk. This has bristles. The leaf stalk is 2-5 mm long. The blade is sword shaped and 2-8 cm long by 0.5-2 cm wide. The flowers are in a slender spike. The spike is spread along the stalk. It tends to bend over. The flowering shoots can be 17 cm long. The individual flowers are small and white. There are 2 subspecies suited to temperate and tropical locations.

It is a temperate plant. It grows in shallow water along the edges of creeks and rivers. It grows in wetlands. It grows in open waste places. It suits sunny wet locations. It can grow from the seashore to 1500 m altitude. Tasmania Herbarium. In Yunnan. In Sichuan.

The stems and leaves are eaten. Young leaves have a strong peppery taste and are used to flavour food. They are finely chopped. The stalks are roasted, then peeled and eaten. The acrid juice is used as a spice. The young seedlings are used to garnish many dishes.

Can be grown by divisions or seedlings.