boxelder (Acer negundo)
fresno de Guajuco (Spanish)
SCIENTIFIC SYNONYMS: There are no scientific synonyms for Acer
CONFIRMATION STATUS: Confirmed.
TAXONOMY: The currently accepted scientific name for boxelder is
Acer negundo L. Numerous varieties of this widely distributed species
have been designated: 1) Acer negundo var. negundo L., 2) Acer negundo
var. interior (Britt.) Sarg., 3) Acer negundo var. violaceum (Kirchn.)
Jaeg., 4) Acer negundo var. texanum Pax., 5) Acer negundo var. californ-
icum Sarg., 6) Acer negundo var. arizonicum Sarg. These varieties appear
to represent fairly distinct geographic races. Intergradation occurs between
varieties and has been considerable between var. violaceum and var. negundo.
The Atlas of Virginia Flora lists var. negundo as the only species of Acer
negundo occurring in Facquier County.
NATIVE STATUS: Native, United States and Canada.
GENERAL BOTANICAL CHARACTERISTICS: Boxelder is a native
deciduous small to large tree with an irregular form. The trunk often di-
vides near the ground into a few long, spreading, rather crooked limbs,
which branch irregularly to support a broad, uneven crown. When grow-
ing among other trees, boxelder forms a high, open crown, with the un-
divided portion of the trunk much longer and usually straighter than that
of an open-grown tree. This variable-sized tree may reach 70 feet (21 m)
in height and 3 feet (0.92 m) in diameter but is more often medium sized,
from 40 to 50 feet (12-15 m) high and from 1 to 2 feet (0.3-0.6 m) in dia-
meter. Boxelder may also appear as a large shrub, and in upland soil on
the Great Plains this tree is usually only about 25 feet (8 m) high with
low, crooked branches.
Boxelder has a fast growth rate and a short life span; it typically lives for 75
years, with 100 years maximum longevity. Growth is rapid when young;
ong, smooth, green annual shoots extend 2 feet (0.6 m) or more in a year.
At maturity growth slows and brittle trunks and limbs shatter; old trunks
frequently put out clusters of sprouts and sometimes develop large burls.
A drought-tolerant tree once established, boxelder's roots are shallow and
spreading, except on deep soils. The bark is light grey and smooth but be-
comes furrowed into narrow, firm ridges and darkens with age. Twigs are
stout, light green to purplish or brownish with a polished look or are often
covered with a whitish bloom that is easily rubbed off. The blunt buds are
0.125 to 0.25 inch (2-5 mm) long with one or two pairs of scales and are
coated with fine white hairs.
Boxelder is the only maple with divided leaves. The three to seven leaflets
are from 6 to 15 inches (15-38 cm) long, light green above and greyish
green below, usually without hairs. The leaflets are shallowly lobed or
coarsely toothed. This completely dioecious tree has pale green male and
female flowers with a strongly pronounced reduction of flower parts, and
contains no rudimentary parts of the opposite sex. Male flowers are on
slender stalks in loose clusters, and female flowers are arranged along a
The fruit is composed of two fused, winged samaras which eventually
separate upon shedding. The angle separating the two wings is less than
60 degrees. The samaras, about 1.5 inches (4 cm) long, hang in long chains
on slender stalks, mature in autumn, and remain on the tree well into the
winter. Each contains a single seed without an endosperm. Seeds are 2 to
3 times as long as they are wide and are markedly wrinkled.
Many ecotypes of this species occur. Varieties are distinguished by the
morphological characteristics of glaucousness, pubescence, or color of the
branches and/or samaras.
REGENERATION PROCESS: Boxelder reproduces both sexually and
asexually. Large seed crops are produced each year. Seeds persist through
the winter; they are dispersed by wind or by birds and squirrels. Wind will
carry these winged seeds up to 100 yards across a snow surface. Boxelder
establishes by seed under a wide range of conditions: immediately after
disturbance on moist disturbed soil, along riverbanks, and in areas with
heavy cover and medium to heavy competition.
Vegetative reproduction is also common on damaged plants of this species.
New shoots will appear on exposed or injured roots. After the extreme
drought condition of the 1930's in the Great Plains, during which nearly all
boxelder trees in shelterbelts 30 years or older died back to the ground,
many trees recovered by producing root sprouts, forming a dense hedge or
undergrowth. In shelterbelts of the northern Great Plains, boxelder has a
dense growing habit resulting from the plant suckering at the root collar.
Although this species will produce abundant sprouts after disturbance, the
primary method of reproduction is through seed, due to the quantity pro-
duced each year and the facility of its distribution.
SITE CHARACTERISTICS: Boxelder generally grows on moist sites
along lakes and streams, on floodplains, and in low-lying wet places where
its shallow root system can find abundant moisture. Hardy to extremes of
climate, boxelder is drought tolerant once well established and can also
withstand short periods of flooding. Soils: This species is able to tolerate a
wide variety of soils but shows a strong preference for well-drained soils.
Although boxelder will grow on soils from gravel to clay, it grows best on
deep, sandy loam, loam, or clay loam soils with a medium to rocky texture
and a pH of 6.5 to 7.5.
SUCCESSIONAL STATUS: Boxelder occurs in a variety of forest
types ranging from early to late seral, making its successional position
difficult to determine. It is moderately shade tolerant but does not repro-
duce in its own shade. It usually establishes under pioneering species such
as cottonwood and willow, particularly in the northern Great Plains, and is
then followed by more shade-tolerant, climax species. In Arizona and New
Mexico, boxelder is a dominant or codominant overstory species in several
high-elevation riparian communities.
SEASONAL DEVELOPMENT: Boxelder flowers from March through
May with or before the appearance of the leaves. The fruit, a winged
samara, ripens from September through October and is dispersed from
September through March. Boxelder's leaves turn a dull yellow color in
the autumn and drop throughout the fall and winter.
GENERAL DISTRIBUTION: Boxelder is widespread in riparian and
palustrine communities throughout most of the contiguous United States.
Its range extends from New Jersey and central New York west through
extreme southern Ontario, central Michigan, northern Minnesota, central
Manitoba, central Saskatchewan, southern Alberta and central Montana,
eastern Wyoming, Utah, and California; and south to southern Texas and
central Florida. It is also local in New Hampshire, Vermont, Massachusetts,
Connecticut, Idaho, and Nevada. Boxelder has been naturalized in Maine,
southern Quebec, New Brunswick, Nova Scotia, Prince Edward Island, and
in southeastern Washington and eastern Oregon. Varieties of boxelder
occur in the mountains of Mexico (Nuevo Leon, San Luis Potosi, and south
to Chihuahua) and in Guatemala. Variety negundo is distributed throughout
the eastern United States and has been introduced to eastern Washington
SKY MEADOWS DISTRIBUTION:
Tree specimens can be found on trails marked in red.
Appalachian Trail/Old Trail
South Ridge/North Ridge
Rolling Meadows/ Lost Mountain
HABITAT TYPES AND PLANT COMMUNITIES: Throughout its
range, boxelder is most often associated with various species of cottonwood
(Populus spp.) and willow (Salix spp.). On the northern Great Plains, box-
elder will generally outlive cottonwood and willow to become an associate
in American elm (Ulmus americana), hackberry (Celtis occidentalis), mul-
berry (Morus spp.), and green ash communities. In the central Great Plains
and in the eastern United States, boxelder occurs with elms (Ulmus spp.),
sugar maple (Acer rubrum), basswood (Tilia spp.), and ashes (Fraxinus
spp.), which eventually replace boxelder in the overstory along with other
more durable and shade-tolerant species. At higher elevations on the Utah
plateaus, boxelder occurs in the riparian zone with water birch (Betula
occidentalis), narrowleaf cottonwood (Populus angustifolia), willows, and
blue spruce (Picea pungens). In New Mexico and Arizona, scattered along
streambeds in riparian forests at higher elevations, boxelder is a typical
canopy dominant with Arizona alder (Alnus oblongifolia) and coyote
willow (Salix exigua).
IMPORTANCE AND USES: Riparian boxelder communities provide
important habitat for many wildlife species and protect livestock from
temperature extremes in summer and winter. Many species of birds
and squirrels feed on the seeds of boxelder. Mule deer and white-tailed
deer use it in the fall as a browse species of secondary importance. The
nutritional value of boxelder is low for livestock, with fair energy value,
poor protein value, and suspected toxicity.
Growth of boxelder is poor on saline, sodic, sodic-saline, and most acidic
soils; it is not recommended for use in rehabilitation of disturbed sites.
This tree's potential for erosion control and for long-term revegetation is
low to medium. In California, Arizona, and parts of Nevada and New
Mexico, boxelder is one of many native species used for revegetating
flood control basins to provide quality wildlife habitat. In the southeastern
United States where soil moisture (or inundation) is likely to be excessive
for several weeks at a time, boxelder is one of the favored flood-tolerant
species recommended for recreation plantings.
Boxelder is not a desired timber species because its wood is light, soft, close
grained, and low in strength. The wood is used locally for boxes and rough
construction, and is used occasionally for cheap furniture and woodenware.
Boxelder was once used for posts, fencing, and fuel but the soft, spongy
wood generally makes poor firewood.
Boxelder, first cultivated in 1688, is often held in low regard as an orna-
mental tree in cities. Its limbs are brittle and break easily; its trunk is
susceptible to rot and infested with boxelder bugs, which make their way
into houses with the arrival of cold weather. The leaves turn a dull yellow
and fall untidily over a long period, as do the winged seeds, giving this
species the reputation of being a "dirty tree". However, because of its
fast growth and drought and cold hardiness, boxelder is popular in rural
communities for street and ornamental plantings; and for shelterbelts.
Boxelder's abundant sap contains a large proportion of sugar as well as
mucilaginous and demulcent properties, and can be made into a pleasant
beverage. The Plains Indians used the sap as a source of syrup, and it is
still used today, but the product is not as sweet as sugar maple syrup.
Crooked Run Valley