Description:
This shrub is 5-15' tall, sending up multiple woody shoots from
the base that branch upward and arch outward. The branches toward the
center of each shrub tend to be straight. Older shoots at the
base of the shrub have gray wrinkled bark, while branches of the basal
shoots
have bark that is gray and more smooth. Twigs are pale brown to reddish
brown, smooth, and hairless with scattered lenticels, while young stems
are light green to green, angular or terete, and usually pubescent.
Pairs of opposite leaves occur along the twigs and young stems. The
leaves are 2-4" long and 1½-3½" across; they are cordate-ovate to
nearly oval and coarsely dentate with 7-18 pairs of teeth along their
margins. The upper leaf surface is yellowish green to dark green and
glabrous to sparsely covered with short appressed hairs. The lower leaf
surface is pale green with prominent veins and variably hairy. The
typical variety of Southern Arrow-Wood has tufts of hair at the
junctions of the lateral veins with the central vein on the lower
surface of each leaf, while var.
deamii
has hairs distributed across
the entire lower surface of each leaf. These hairs are short, white,
slightly appressed, and either simple or stellate. The petioles
are ¼-1" long, light green, and usually pubescent. At the petiole
bases, there are no pairs of stipules.
Flat-headed panicles
of flowers about 2-4" across are produced from the tips of
leafy stems or
short spur-stems. The branching stalks of each panicle are light green
to yellowish green and usually pubescent. Individual flowers are about
¼" across, consisting of a white corolla with 5 spreading lobes, a very
short calyx with 5 teeth, 5 stamens, and a pistil with a single style.
The stamens are strongly exerted from the corolla. The blooming period
occurs from
late spring to early summer for about 3 weeks. In each panicle, the
flowers come into bloom at about the same time. The floral scent is
malodorous. Afterwards, the flowers are replaced by small drupes about
¼" across that are globoid to ovoid-globoid in shape and blue-black at
maturity. Each drupe contains a single stone (seed with a hard coat)
that is ovoid in shape, somewhat flattened, and grooved along one
side. The woody root system is shallow and branching, sometimes
producing underground runners that form clonal offsets.
Cultivation:
The preference is full or partial sun, moist to mesic conditions, and
soil containing loam, silt, sand, or rocky material. This shrub has
relatively few problems with disease organisms and it is easy to
cultivate.
Range
& Habitat: Southern Arrow-Wood is native to
southern Illinois, where it is rare in natural areas. In other areas of
the state, it may be encountered as an escape
from cultivation. Habitats include thinly wooded slopes, openings in
bottomland woodlands, woodland borders, streambanks, and fence rows.
This shrub is cultivated throughout the state as an ornamental
landscape plant, although it rarely seems to escape. However, it may be
confused with the more common
Viburnum
recognitum (Smooth Arrow-Wood),
which is sometimes regarded as a variety of Southern Arrow-Wood.
Occasional disturbance is beneficial if it reduces competition from
canopy trees.
Faunal
Associations: The unpleasantly scented
flowers attract Halictid bees, Andrenid bees, flies, and beetles. Both
nectar and pollen are available as floral rewards. Fly floral visitors
include Syrphid flies, dance flies (
Empis
spp.,
Rhamphomyia
spp.),
Tachinid flies, Chloropid flies, and others. Beetle floral visitors
include long-horned beetles (Cerambycidae), leaf beetles
(Chrysomelidae), Dermestid beetles, tumbling flower beetles
(Mordellidae), Scarab beetles, and others. To a lesser extent,
bumblebees, other long-tongued bees, butterflies, and skippers may
visit the flowers for nectar. Caterpillars of the butterfly
Celastrina
argiolus (Spring/Summer Azure) feed destructively on the
flowers and buds of
Viburnum
spp., while some moth caterpillars feed
primarily on the foliage of these shrubs. The latter include
such species as
Agriopodes
fallax (The Green Marvel),
Calledapteryx dryopterata
(Brown Scoopwing),
Coleophora
viburniella,
Hyparpux aurora
(Pink Prominent),
Metaxaglaea
inulta (Unsated Sallow),
Schizura badia
(Chestnut Schizura), and
Zale
horrida (Horrid Zale).
Other insect feeders include
Pyrrhalta
viburni (Viburnum Leaf
Beetle); wood-boring larvae of the long-horned beetle
Oberea
schaumi; the plant bugs
Lygidea viburni and
Lygocoris viburni;
and the
aphids
Aphis
viburniphila,
Ceruraphis
viburnicola, and
Nearctaphis
bakeri.
The fruits of Southern Arrow-Wood and other
Viburnum spp. are
consumed to some extent by a variety of upland gamebirds and songbirds,
including the Brown Thrasher, Northern Mockingbird, Pileated
Woodpecker, Wild Turkey, Blue-Headed Vireo, and Swainson's Thrush (see
the
Bird Table for a
more complete listing of these
species). Mammals eat the fruit to a more limited extent; they
include the Black Bear, Red Fox, Striped Skunk, Opossum, Fox
Squirrel, Gray Squirrel, and White-Footed Mouse. White-Tailed Deer have
been known to browse on the twigs and foliage of these shrubs, but it
is not preferred as a source of food. Near bodies of water, the
beaver occasionally feeds on the bark and branches and also uses them
in the construction of its lodges and dams. The Indigo Bunting, Prairie
Warbler, White-Eyed Vireo, and other songbirds sometimes construct
nests in the branches of
Viburnum
spp.
Photographic
Location:
Along a fence row near the University of Illinois in Urbana, Illinois.
The photographed shrub is the more hairy variety of Southern
Arrow-Wood,
Viburnum
dentatum deamii.
Comments: Southern
Arrow-Wood is very similar in appearance to Smooth Arrow-Wood (
Viburnum
recognitum), except its leaf undersides are more hairy and
they are
never whitened. Another species,
Viburnum
molle (Soft-Leaved Arrow-Wood),
differs from Southern Arrow-Wood by having leaves that are more cordate
in shape and berries that are more narrowly ovoid in shape. The leaves
of Soft-Leaved Arrow-Wood also tend to have more pairs of teeth along
their
margins (often exceeding 20 pairs per leaf). Another similar species,
Viburnum rafinesquianum
(Downy Arrow-Wood), is a smaller shrub (up to
6' tall) with smaller leaves (up to 3" in length). The leaves of Downy
Arrow-Wood also tend to have fewer pairs of teeth along their margins
(less than 10 pairs per leaf) than those of Southern Arrow-Wood. Within
the
Viburnum genus, species in the Arrow-Wood group have leaves with coarse
dentate teeth and their flowers are malodorous. In contrast, species in
the Viburnum group have leaves with fine teeth and their flowers are
sweetly scented.