Persicaria maculosa

An annual herb native from temperate Eurasia to Indochina and from Macaronesia to northern Africa, it belongs to the Polygonaceae family. It is widely naturalized in both hemispheres and is invasive in parts of North America, where dense growth can compete with native plants and crops. It grows in moist disturbed ground, with erect or spreading stems that are often reddish. The narrow leaves usually bear a dark central blotch. A fringed, tubular sheath surrounds the stem at each leaf base. Dense, spike-like clusters contain small pink or occasionally white flowers. The fruits are shiny, brownish black nuts, either flattened or three-sided. Its seeds provide food for birds and mammals. Photographed in Colombia.