Description:
This deciduous tree is typically 30-60' tall, sometimes becoming up to
90' tall. It forms a single trunk about ¾-2' across that is often
crooked or leaning, while the crown is usually irregular and narrow. On
older trees, trunk bark is gray, somewhat rough-textured, flaky, and
irregularly fissured. The trunk bark of young trees, in contrast, is
light gray, relatively smooth, and often warty. However, various
lichens may discolor the bark. Branch bark and twigs are light gray and
relatively smooth; twigs are also terete with scattered white
lenticels. Young shoots are light to medium green and either glabrous
or mostly glabrous (sometimes with patches of short pubescence near the
bases
of petioles); the terminal buds of these shoots are nearly
black, short-conical in shape, and about ¼" long (see
Photo).
Pairs of
opposite compound leaves occur along the twigs and young shoots. These
compound leaves are odd-pinnate with 7-11 leaflets; they are about
10-18" long. The petioles and rachises (central stalks) of these leaves
are light green or light reddish green and mostly glabrous, although
the undersides of the rachises have patches of short brown
pubescence near the bases of the leaflets.
Individual leaflets are 3-5½" long and 1-2" across; they are
lanceolate-oblong or elliptic-oblong in shape and finely serrated along
their margins. The lateral leaflets are sessile, while the terminal
leaflet has a petiolules (basal stalklet) up to ½" long. The upper
leaflet
surface is medium to dark green and glabrous, while the lower leaflet
surface is pale green and mostly glabrous. However, there are tufts of
short brown pubescence along the bases of the lower leaflet
surfaces. Leaf venation is pinnate.
Black Ash can be either dioecious
or monoecious; it less commonly produces perfect flowers. These
purplish flowers are produced in compact clusters during the spring
before the vernal leaves develop. Male flowers are about 3 mm. (1/8")
long, each one consisting of a pair of stamens; they lack calyces and
corollas.
Female flowers are about 3 mm. (1/8") long, each one consisting of a
pistil; they
lack corollas and their calyces are absent or insignificant. These
flowers are cross-pollinated by the wind. Afterwards, fertile female
flowers
are replaced by single-seeded samaras that are narrowly oblong
in shape, about 1-1½" long, and 6-8
mm. across. These samaras are more tapered at their bases than
at their
tips; the latter are rounded or slightly notched. Except where their
seeds occur, the samaras are flat. The winged membranes of the
samaras extend downward past the edges of the seeds to their bases. The
samaras are distributed by water or wind. The root system is widely
spreading and shallow. This tree spreads by reseeding itself.
Cultivation:
The preference is full or partial sun, wet conditions, and soil
containing loam, sandy loam, clay-loam, or peaty material. This tree
has a wide pH tolerance. The seeds can take 2-3 years to germinate.
Black Ash usually lives up to 150 years, although some trees may live
up to 250 years. Flooded conditions can be tolerated for up to 2 months
during the growing season.
Range
& Habitat: The native Black
Ash (
Fraxinus nigra)
is occasional in northern Illinois, uncommon in
central Illinois, and rare or absent in the southern section of the
state (see
Distribution
Map). Illinois lies along the southwestern range limit of
this mostly
boreal species. Habitats include swamps, flatwoods, shady seeps and
springs, White Cedar fens, wet depressions in wooded areas, low areas
along lakes, and forested bogs. In Illinois, this tree is found in
higher quality natural areas. In deciduous woodlands, common associates
of this tree include
Acer
saccharinum (Silver Maple),
Fraxinus
pennsylvanica (Green Ash, Red Ash),
Quercus bicolor
(Swamp White Oak), and the
herbaceous
Caltha
palustris (Marsh Marigold). Black Ash is
able
to survive top kill from a wildfire by resprouting from the base of its
trunk.
Faunal Associations: Various insects feed on the leaves,
wood, plant
juices, and other parts of Black Ash and other
Fraxinus spp.
These
insect species include the wood-boring larvae of long-horned beetles,
plant bugs (mostly
Tropidosteptes
spp.), lace bugs, aphids, larvae of
gall flies, and caterpillars of many moths (see
Insect Table and
Moth
Table). The seeds of these trees are eaten by such birds as
the Wood
Duck, Wild Turkey, Cardinal, Pine Grosbeak, and Cedar Waxwing; the
Yellow-Bellied Sapsucker drills holes into the trunks of the trees to
obtain sap. Mammals feed on
Fraxinus
spp. in various ways. The Black
Bear, Fox Squirrel, Red Squirrel, White-Footed Mouse, and Meadow Vole
eat the seeds. In addition, the Beaver feeds on the bark and wood,
while the White-Tailed Deer feeds on the twigs and foliage. The
Silver-Haired Bat (
Lasionycteris
noctivagans) and other bats use such
trees as summer roosts and nursery colonies, particularly when they are
located near openings over meadows, fields, or bodies
of water. Black Ash, in particular, provides habitat for such
amphibians as tree frogs,
wood frogs, and spring peepers in forested wetlands.
Photographic Location: An oak flatwoods and shady seep at
the Horseshoe
Bottoms in Vermilion County, Illinois.
Comments:
Among the Ash trees (
Fraxinus
spp.) in Illinois, Black Ash (
Fraxinus
nigra) has the most northern distribution and it is
usually smaller in
size. Other common names of this tree include Basket Ash, Hoop Ash, and
Swamp Ash. The wood of Black Ash is relatively soft and flexible. It is
relatively easy to split and can be separated into thin strips. The
wood has been used to make cabinets, veneer, baskets, barrel hoops, and
the seats of chairs. Black Ash can be distinguished from other ash
species by its sessile lateral leaflets and by the tufts of short brown
pubescence on the bases of its leaflet undersides and adjacent areas of
its rachises. The trunk bark
of Black Ash is also unlike its counterparts in this genus: it is
relatively smooth, flaky, and irregularly fissured. In contrast, both
White Ash (
Fraxinus
americana) and Green/Red Ash
(Fraxinus pennsylvanica)
have coarsely textured trunk bark with deep interlacing furrows and
ridges.