Populus x, Moench

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1964, Flora Europaea - Volume 1. Lycopodiaceae to Platanaceae, Cambridge University Press : 55

9. P. x canadensis Moench , Verz. Ausl. Bäume Weissenst. 81 (1785)

( P. deltoides x nigra ).

Like 8 but much quicker-growing; trunk without bosses; twigs almost terete or slightly angled; leaves crenate-serrate, shortly cibate; stamens 15-25. Originated probably in France c. 1750; now planted almost throughout Europe for shelter and for timber.

Several clones are known in cultivation, which apparently arose independently in different places; the most important are:

(i) cv. Serotino, the oldest, staminate, up to 40 m high, with broad crown, glabrous twigs and deltate leaves. Extensively planted in W. & C. Europe.

(ii) cv. Serotino de Selys, like (i) but fastigiate. Arose in Belgium before 1818.

(iii) cv. Regenerata , pistillate, very similar to cv. Serotina but coming into leaf two weeks earlier; known since 1814. Extensively planted in C. Europe.

(iv) cv. Marilandica , pistillate, differing from cv. Serotina in its more spreading branches; leaves rhombic-ovate, coming into leaf earlier. Much cultivated in C. Europe.

(v) cv. Gelrica , staminate, very quick-growing tree with reddish shoots, coming into leafbetween cv. Serotina and cv. Marilandica . Extensively planted in C. Europe and the Netherlands.

(vi) cv. Italia 214, pistillate, with erecto-patent branches; young shoots red, glabrous; leaves large, deltate. Extensively planted in S. Europe.

(vii) cv. Robusta , like (i), but with pubescent twigs and petioles. Extensively planted in C. & N. W. Europe.

A closely related species is P. monilifera Aiton ( P. canadensis Michx fit, non Moench, P. deltoides var. monilifera (Aiton) A. Henry ), from Canada and N.E. United States, which is like 9 but has slightly angled or almost terete twigs, broadly ovate leaves 7-12 cm, wider than long, cuspidate, shallowly cordate at the base, and thinner. It is very rarely cultivated in Europe, though its name is commonly used erroneously for both 8 and 9.