Latin: Persicaria maculosa

Other names: Redshank knotweed, persicaria, lady’s thumb

Family: Polygonaceae

Redshank is a common weed found in the United Kingdom that belongs to the buckwheat family (Polygonaceae). It is also known as redshank knotweed, persicaria, or lady’s thumb. Redshank is an annual plant known for its upright growth habit, reddish stems, and distinctive pink to reddish flower spikes.

Identifying Redshank

A crop of wheat almost smothered with redshank

A crop of wheat almost smothered with redshank

Redshank possesses several distinct features that help distinguish it from other similar-looking plants. The stems of redshank are erect and often have a reddish tint, especially near the nodes. The leaves are lance-shaped or oval and have distinct dark spots or “thumbprints” on them, which give rise to the common name “lady’s thumb.”

The flowers of redshank are borne on tall, slender spikes that can reach lengths of up to 15 centimeters. The flower spikes are pink to reddish in color and are densely packed with small flowers. The flowers typically bloom from late spring to early autumn.

The Challenges of Redshank

Redshank can be a problematic with its ability to produce abundant seeds and its adaptability to a range of soil conditions make it a challenging species to control. Redshank can compete with crops and desirable plants for resources such as nutrients, water, and sunlight. It can also interfere with harvesting and reduce crop yield and quality.

One of the challenges with redshank is its rapid growth and ability to regrow from root fragments.