PERSICARIA

Genus of about 150 annuals and perennials. They may be evergreen, semi-evergreen or deciduous and many spread by stolons leading to a spreading habit which can be invasive. This habit and their commonly used name knotweed can give cause for concern but used wisely they are worthy performers. They are found in a variety of habitats worldwide and most have long-lasting spikes of flowers followed by distinctive 3-angled or ovoid fruits.