Populus deltoides W.Bartram ex Marshall, Arbust. Amer.

Verloove, Filip & Ardenghi, Nicola M. G., 2015, New distributional records of non-native vascular plants in northern Italy, Natural History Sciences 2 (1), pp. 5-14 : 11

Populus deltoides W.Bartram ex Marshall, Arbust. Amer. : 106. 1785. [ Fig 5 ]

( Salicaceae )

Casual neophyte new to the flora of the province of Lodi (Lombardia) ( Banfi & Galasso, 2010).

ITALY. Lombardia. Prov. Lodi: San Rocco al Porto, river Po W of the bridge, river bank, several young, self-sown trees, 13.09.2014, F. Verloove 11059 ( BR) .

This North American native is widely planted in Europe, although much less so than P. × canadensis Moench (pro sp.), its hybrid with native P. nigra L. It is reported to be an exceptional escape from cultivation in Lombardia, only being known from three localities in the Pavia area since 1905 ( Banfi & Galasso, 2010; Ardenghi, 2013). In San Rocco al Porto several young, obviously self-sown trees were seen on the sandy banks of river Po.

Populus deltoides is a distinct species with leaves up to 18 cm long or even longer, provided with more prominent and hooked marginal teeth. These features distinguish it from juvenile individuals of P. × canadensis , which usually bear leaves larger than those of the adult trees (see Eckenwalder, 2010).

Figures

Fig. 5 - Populus deltoides, San Rocco al Porto (LO), September 2014 (Photo: F. Verloove).