The ash
tree is any tree of the genus Fraxinus of the olive family (Oleaceae). The
genus includes about 70 species of trees and shrubs, mostly
distributed throughout the
Northern Hemisphere, some of which are
valuable for their timber and beauty. A few species extend into the
tropical forests of
Mexico and Java.
The leaves of ash trees are
opposite, usually
deciduous, and pinnately compound and have an
odd number of leaflets, often five to nine. The one-seeded fruits are
narrow and
winged and are called samaras. The flowers usually are
small and showy and grow in clusters, and some species have
petaled blooms. Most ash trees are small to medium in height,
though some of the larger
timber-providing species grow to 18-34 m
(60-120 feet).
Eighteen species of ash are found in
the United States, with five furnishing most of the
ash lumber cut. The most important are the white ash (F. americana) and the green
ash (F. pennsylvanica), which grow throughout the
eastern and much of the central
United States and northward into parts of
Canada. These two species furnish
wood
that is stiff, strong, resilient, and yet lightweight. This "white ash" is used for baseball
bats,
hockey sticks, paddles and
oars, tennis and other racket frames, and the
handles of shovels, spades, hoes, rakes, and other agricultural tools.
The black ash (F.
nigra) of eastern North America, the blue ash (F. quadrangulata) of the
Midwest, and
the Oregon ash (F. latifolia) of the Pacific Northwest furnish wood of comparable quality
that is used for
furniture, interior paneling, and barrels, among other purposes. The
Mexican ash (F. uhdei), a broad-crowned tree that is widely planted along the
streets
of
Mexico City, reaches a height of 18 m and has leaves with five to nine leaflets.
The
European ash (F. excelsior), with 7 to 11 leaflets, is a timber tree of wide
distribution throughout
Europe. A number of its varieties have been cultivated and
used in landscaping for
centuries. Notable among these are forms with dwarflike or
weeping habits, variegated
foliage, warty twigs and branches, and curled leaves. The
flowering ash (F. ornus) of southern Europe produces
creamy white,
fragrant flowers,
has leaves with seven leaflets, and reaches 21 m. It is also known as manna ash for a
laxative that is extracted from its gum. The
Chinese ash (F. chinensis) yields Chinese
white
wax.