Resembling spearmint, this herb has purplish stems with dark green, tapered smooth leaves growing sparsely along angled stems. It has a strong mint flavor, with overtones of basil. Long, slender flower stems are topped with dense clusters of tiny white or pink blossoms.
History and mythology
The common name of “knotweed” describes the swollen, jointed appearance of the stems of this herb. Polygonum literally means “many-kneed,” referring to the many angles in the stem. There are over 200 species of Polygonum, some of them included in medical Pharmacopeias of Switzerland, France, and Russia since Renaissance times. An important spring food in Northern Europe from early times it was also called “bistort”.
Various uses
Culinary
Polygonum, sometimes referred to as Asian mint or Vietnamese mint, is popular in Malaysia for use in fish and noodle dishes and features in the characteristic Nonya cuisine. In Thailand the shoots and leaves are eaten raw with nam prik (shrimp sauce) or added to curries. It is known as “daun keson” in Indonesia and Malaysia, and “rau ram” in Vietnam.
Medicinal
The dried rhizome has astringent and anti-inflammatory uses. In Europe, an infusion from the rhizome has been used as a gargle for ulcers and gingevitis, and applied to cuts, sores and haemorrhoids.