enters the tropics, crosses the equator, and appears in the mountains of
Peru and Chili.... The books record one hundred and sixty species in the
world, and these sport and hybridize to their own content and to the
despair of botanists. Then, too, it comes of an ancient line; for
impressions of leaves in the cretaceous rocks show that it is one of the
oldest of plants."

Common it is, and therefore overlooked; but the reader may well resolve
to watch the willow in spring and summer, with its bloom and fruit; to
follow its refreshing color through winter's chill; to observe its cheer
and dignity; and to see the wind toss its slender wands and turn its
graceful leaves.

The poplars and the willows are properly considered together, for
together they form the botanical world family of the _Salicaceae_. Many
characteristics of bloom and growth, of sap and bark, unite the two, and
surely both, though alike common to the world, are common and familiar
trees to the dwellers in North America.

[Illustration: White poplars in spring-time]

One of my earliest tree remembrances has to do with a spreading
light-leaved growth passed under every day on the way to school--and,
like most school-boys, I was not unwilling to stop for anything of
interest that might put off arrival at the seat of learning. This great
tree had large and peculiar winter buds, that always seemed to have
advance information as to the coming of spring, for they would swell out
and become exceedingly shiny at the first touch of warm sun. Soon the
sun-caressing would be responded to by the bursting of the buds, or the
falling away of their ingenious outer protecting scales, which dropped
to the ground, where, sticky and shining, and extraordinarily aromatic
in odor, they were just what a curious school-boy enjoyed investigating.
"Balm of Gilead" was the name that inquiry brought for this tree, and
the resinous and sweet-smelling buds which preceded the rather
inconspicuous catkins or aments of bloom seemed to justify the Biblical
designation.

Nearly a world tree is this poplar, which in some one of its variable
forms is called also tacamahac, and balsam poplar as well. Its cheerful
upright habit, really fine leaves and generally pleasing air commend it,
but there is one trouble--it is almost too vigorous and anxious to
spread, which it does by means of shoots or "suckers," upspringing from
its wide area of root-growth, thus starting a little forest of its