Other characters: The buds are small, brown, and smooth, while those of the European elms are covered with down. The small side twigs come out at almost right angles to the larger terminal twigs, which is not the case in other species of elm.
Fig. 40.—Leaf of Carolina Poplar.
Other common names: White elm.
Comparisons: The English elm (Ulmus campestris) is also a tall, dignified tree commonly seen under cultivation in America, but may be told from the American species by the difference in their general contour. The branches of the English species spread out but do not arch like those of the American elm, and the bark of the English elm is darker and coarser, [Fig. 38]. Little tufts of dead twigs along the main branches and trunk of the tree are characteristic of the English elm and will frequently help to distinguish it from the American elm.
The Camperdown elm may be recognized readily by its dwarf size and its low drooping umbrella-shaped crown.
Lombardy or Italian Poplar (Populus nigra, var. italica)
Distinguishing characters: Its tall, slender, spire-like form and rigidly erect branches, which commence low on the trunk, make this tree very distinct at all seasons of the year. See [Fig. 39].
Leaf: Triangular in shape, similar to that of the Carolina poplar but smaller, see [Fig. 40].