[Illustration: The Carolina poplar as a street tree]

But I must not get into the economics of street-tree planting. I started
to tell of the blossoms of this same Carolina poplar, which are
decidedly interesting. Just when the sun has thoroughly warmed up the
air of spring there is a sudden, rapid thickening of buds over one's
head on this poplar. One year the tree under my observation swelled and
swelled its buds, which were shining more and more in the sun, until I
was sure the next day would bring a burst of leaves. But the weather was
dry, and it was not until that wonderful solvent and accelerator of
growing things, a warm spring rain, fell softly upon the tree, that the
pent-up life force was given vent. Then came, not leaves, but these long
catkins, springing out with great rapidity, until in a few hours the
tree glowed with their redness. A second edition of the shower, falling
sharply, brought many of the catkins to the ground, where they lay about
like large caterpillars.

The whole process of this blooming was interesting, curious, but hardly
beautiful, and it seemed to fit in with the restless character of the
poplar family--a family of trees with more vigor than dignity, more
sprightliness than grace. As Professor Bailey says of the cottonwood,
"It is cheerful and restive. One is not moved to lie under it as he is
under a maple or an oak." Yet there are not wanting some poplars of
impressive character.

One occurs to me, growing on a wide street of my home town, opposite a
church with a graceful spire. This white or silver-leaved poplar has for
many years been a regular prey of the gang of tree-trimmers, utterly
without knowledge of or regard for trees, that infests this town. They
hack it shamefully, and I look at it and say, "Well, the old poplar is
ruined now, surely!" But a season passes, and I look again, to see that
the tremendous vigor of the tree has triumphed over the butchers; its
sores have been concealed, new limbs have pushed out, and it has again,
in its unusual height, assumed a dignity not a whit inferior to that of
the church spire opposite.

[Illustration: Winter aspect of the cottonwood tree]

This white poplar is at its best on the bank of a stream, where its
small forest of "suckers" most efficiently protects the slope against
the destructive action of floods. One such tree with its family and
friends I saw in full bloom along the Susquehanna, and it gave an
impression of solidity