la_)
(Swamp Cottonwood, Downy Poplar). The largest deciduous tree of
Washington. Very common. Heartwood dull brown, sapwood lighter brown.
Wood soft, close-grained. Is now manufactured into lumber in the West
and South, and used in interior finish of buildings. Northern Rocky
Mountains and Pacific region.

=95. Poplar= (_Populus grandidentata_) (Large-Toothed Aspen).
Medium-sized tree. Heartwood light brown, sapwood nearly white. Wood
soft and close-grained, neither strong nor durable. Chiefly used for
wood pulp. Maine to Minnesota and southward along the Alleghanies.

=96. White Poplar= (_Populus alba_) (Abele-Tree). Small to medium-sized
tree. Wood in its quality and uses similar to the preceding. Found
principally along banks of streams, never forming forests. Widely
distributed in the United States.

=97. Lombardy Poplar= (_Populus nigra italica_). Medium-to large-sized
tree. This species is the first ornamental tree introduced into the
United States, and originated in Afghanistan. Does not enter into the
markets. Widely planted in the United States.

=98. Balsam= (_Populus balsamifera_) (Balm of Gilead, Tacmahac). Medium-
to large-sized tree. Heartwood light brown, sapwood nearly white. Wood
light, soft, not strong, close-grained. Used extensively in the
manufacture of paper pulp. Common all along the northern boundary of
the United States.

=99. Aspen= (_Populus tremuloides_) (Quaking Aspen). Small to
medium-sized tree, often forming extensive forests, and covering
burned areas. Heartwood light brown, sapwood nearly white. Wood light,
soft, close-grained, neither strong nor durable. Chiefly used for
woodenware, cooperage, and paper pulp. Maine to Washington and
northward, and south in the western mountains to California and New
Mexico.

RED GUM (See Gum)

SASSAFRAS

=100. Sassafras= (_Sassafras sassafras_). Medium-sized tree, largest in
the lower Mississippi Valley. Wood light, soft, not strong, brittle,
of coarse texture, durable in contact with the soil. The sapwood
yellow, the heartwood orange brown. Used to some extent in slack
cooperage, for skiff- and boatbuilding, fencing, posts, sills, etc.
Occurs from New England to Texas and from Michigan to Florida.

SOUR GUM (See Gum)

SOURWOOD

=101. Sourwood= (_Oxydendrum arboreum_) (Sorrel-Tree). A slender tree,
reaching the maxim