Persicaria pensylvanica (L.) M.Gómez, Anales Inst. Segunda Enseñ., 2: 278. 1896.

( Polygonaceae)

Naturalized neophyte new for the flora of the province of Mantova (Lombardia) (Banfi & Galasso, 2010).

ITALY. Lombardia. Prov. Mantova: Viadana, river Po W of the bridge, sandy river bank, few plants, 15.09.2014, F. Verloove 11058 (BR) .

A native of North America, this species became naturalized in Europe, especially in riparian habitats. In Italy it is known from the northernmost regions (Celesti-Grapow et al., 2009a). It is here reported for the first time from Mantova province in Lombardia.

This species is obviously naturalized along river Po but usually occurs in small populations. It does not seem to be an aggressive invader.