PERSICARIA

PERSICARIA

POLYGONACEAE

Known as Bistort or Knotweed, this is a wide-ranging genus, including arable weeds and medicinal plants and in a wide variety of sizes, from prostrate ground-cover plants to tall, upright border perennials.

There are about 17 species, native predominately to the Himalayas and China, where they grow in damp wood- or grassland.

Most prefer moist, humus-rich soil in sun or part-shade, but many tolerate drier conditions once established. Some can be invasive.