Polygonum amphibia · būdmainis rūgtis
https://en.wikipedia.org/wiki/Persicaria_amphibia Persicaria amphibia is native to a large area across the northern hemisphere, including Europe, Asia, North America, and parts of Africa. It has been introduced elsewhere, such as South America and other parts of Africa.
It grows in many types of wet habitat, such as ponds, streams, and marshes. It is a rhizomatous perennial herb which takes a variety of forms and is quite variable in morphology. It may be an aquatic plant, growing submerged or floating in water bodies, it may grow in muddy and wet areas which are periodically inundated, and it may grow in moist spots on land, such as in meadows.