: (1) The needle-leaved, naked-seeded conifers, such
as pine, cedar, etc., (2) the broad-leaved trees such as oak poplar,
etc., and (3) to an inferior extent by the (one-seed leaf) palms,
yuccas, and their allies, which are confined to the most southern
parts of the country.

Broad-leaved trees are also known as deciduous trees, although,
especially in warm countries, many of them are evergreen, while the
needle-leaved trees (conifers) are commonly termed "evergreens,"
although the larch, bald cypress, and others shed their leaves every
fall, and even the names "broad-leaved" and "coniferous," though
perhaps the most satisfactory, are not at all exact, for the conifer
"ginkgo" has broad leaves and bears no cones.

Among the woodsmen, the woods of broad-leaved trees are known as
"hardwoods," though poplar is as soft as pine, and the "coniferous
woods" are known as "softwoods," notwithstanding the fact that yew
ranks high in hardness even when compared with "hardwoods."

Both in the number of different kinds of trees or species and still
more in the importance of their product, the conifers and broad-leaved
trees far excel the palms and their relatives.

In the manner of their growth both the conifers and broad-leaved trees
behave alike, adding each year a new layer of wood, which covers the
old wood in all parts of the stem and limbs. Thus the trunk continues
to grow in thickness throughout the life of the tree by additions
(annual rings), which in temperate climates are, barring accidents,
accurate records of the tree. With the palms and their relatives the
stem remains generally of the same diameter, the tree of a hundred
years old being as thick as it was at ten years, the growth of these
being only at the top. Even where a peripheral increase takes place,
as in the yuccas, the wood is not laid on in well-defined layers for
the structure remains irregular throughout. Though alike in the manner
of their growth, and therefore similar in their general make-up,
conifers and broad-leaved trees differ markedly in the details of
their structure and the character of their wood.

The wood of all conifers is very simple in its structure, the fibres
composing the main part of the wood all being alike and their
arrangement regular. The wood of the broad-leaved trees is complex in
structure; it is made up of different kinds of cells and fibres and
lacks the regularity of arrangement so noticeable in the conifers.
This differ