There is wide divergence of opinion and practice as to the limits and names of species. Probably, some of the difficulty in distinguishing native species of Populus is due to the fact that we have not recognized the presence of European or other hybrids in this country. Poplars are amongst the easiest of all trees to propagate and grow. They thrive in almost any soil, although the cottonwood is most at home in lowlands and along streets, at least in the East. Poplars are rapid growers.
Poplars have their interest as specimen trees as distinctly as do other kinds of trees.
P. alba is a large much branched tree with whitish bark on the young branches. P. nigra is a tree of medium to large size, with smooth twigs and leaves somewhat resembling those of the cottonwood. The tree usually has a pyramidal habit of growth and a dark cast to the foliage. Is rarely seen, even in cultivation grounds. With the exception of variety italica, these forms are little known in this country.