Muhlenbergia frondosa (Poir.) Fernald, Rhodora, 45 (534): 235. 1943.

( Poaceae)

Naturalized neophyte new to the flora of Emilia-Romagna (Conti et al., 2005; Celesti-Grapow et al., 2009a).

ITALY. Emilia-Romagna. Prov. Reggio nell’Emilia: Boretto, river Po E of the bridge, riparian woodland, locally, 13.09.2014, F. Verloove 11000 (BR, MSNM) .

Muhlenbergia frondosa is a native species in southern Canada and the contiguous U.S.A. (Peterson, 2003). It is only rarely seen outside of its native distribution range. However, in Italy it is known since several decades from Piemonte (Soldano, 1977) where it is naturalized, for instance in riparian woodland alongside river Sesia. In recent years it seems to spread in northern Italy: Bertolli & Prosser (2013) reported about its discovery in Trentino-Alto Adige and in September 2014 it was also detected alongside river Po in Boretto. This species is rather inconspicuous and often very reluctant to flower; it may be more widespread but overlooked.