Description:
This multi-stemmed shrub is up to 15' tall and abundantly branched. The
woody stems are covered with relatively smooth gray bark; short raised
lenticels are scattered across this bark. Depending on the ecotype,
some shrubs may have short spur-branches that have a
thorny appearance. Young twigs are light brown or dull reddish
purple and hairy; some hairs are long, while other hairs are short.
Pairs of opposite leaves occur along the twigs. The leaf blades are
¾-2" long and about one-half as much across; they are ovate-oblong to
obovate-oblong to broadly ovate and
their margins are smooth. The upper leaf surface is medium green and
hairless (or nearly so), while the lower surface is pale green and
hairless, except
along the midrib of each leaf underside, which is
finely hairy. The
short petioles are nearly non-existent to ¼" in length; they are
usually pubescent.
Leafy twigs terminate in panicles of white
flowers about 1-2" long; these panicles are pyramidal to ovoid in
outline. In addition to the central stalk, each panicle has a few short
lateral stalks that terminate in the pedicels of the
flowers. These stalks are light green, light
brown, or reddish purple; both long and short hairs are present.
The pedicels are less than 1/8" (3 mm.) long and usually pubescent.
Individual
flowers are 1/4-1/3" (6-8 mm.) long, consisting of
a trumpet-shaped white corolla and a very short tubular calyx that is
pale green to pale yellow. The corolla has 4 spreading lobes that are
about one-half the length of the corolla tube, while the calyx has 4
shallow teeth. Each flower also has two stamens with pale yellow
anthers and
a pistil with a single style; the stamens extend to about the base, or
a little beyond the base, of each corolla's lobes. The blooming period
occurs during late spring for about 1½ weeks. The flowers have a strong
fragrance that is sweet with musty overtones. Afterwards,
they wither away and are replaced
by berries that often
persist until the fall or winter. At maturity, individual berries are
about ¼" long, ovoid-globoid in shape, and bluish black with a dull
white bloom; the interior of these berries is juicy and seedy.
Cultivation:
The preference is full sun to light shade, moist to dry-mesic
conditions, and soil containing loam or clay-loam. Possibly other soil
types are acceptable as well. This introduced shrub is easy to
cultivate, but it may become invasive in some areas.
Range
&
Habitat: The non-native Border Privet has naturalized in
only a few
counties of Illinois (see
Distribution
Map); it is a rare shrub in
the wild. However, these records may underestimate its true
distribution within the state, and it may become more common in the
future. Border Privet was introduced from Japan or China as an
ornamental shrub that can be clipped into a hedge. In naturalized
areas, habitats include woodland openings, thickets, roadsides, and
vacant lots. Border Privet is often cultivated in yards, parks,
cemeteries, and other properties. This shrub has the potential
to become invasive within the state.
Faunal
Associations: The
flowers offer nectar and pollen as rewards to floral visitors. These
visitors include honeybees and other bees, the Red Admiral and other
butterflies, and probably other insects. The foliage of Privet shrubs
(
Ligustrum spp.)
is eaten by the caterpillars of some Sphinx moths,
specifically:
Ceratomia
undulosa (Waved Sphinx),
Sphinx chersis
(Great
Ash Sphinx), and
Sphinx
kalmiae (Laurel Sphinx). The caterpillars of
Podesesia syringae
(Lilac Borer Moth) bores through the woody stems of
these shrubs, as do the larvae of the long-horned beetle,
Tylonotus
bimaculatus (Ash & Privet Borer). Other insect
feeders include the
aphid,
Macrosiphum gei,
and the flea beetle,
Trichaltica
scabricula
(Hottes & Frison, 1931; Clark et al., 2004). Among vertebrate
animals, the berries are eaten to a limited extent by such songbirds as
the Eastern Bluebird, American Tree Sparrow, and Cedar Waxwing (Martin
et al., 1951/1961). These birds spread the seeds to new
areas. The foliage of Border Privet is more or less toxic to mammalian
herbivores and it
is usually shunned by them. Both the foliage and berries are toxic to
humans.
Photographic
Location: Along a sidewalk at the border of a cemetery in
Urbana,
Illinois.
Comments:
Several varieties and subspecies of Border Privet have been described
in China and Japan, although the cultivars of this shrub in the United
States usually resemble the typical variety or subspecies. Several
species of Privet shrubs in Illinois have been introduced from either
Europe or Asia, but only Border Privet and Common Privet (
Ligustrum vulgare)
are known to naturalize within the state. Common Privet
is relatively difficult to distinguish from Border Privet, but some
useful distinctions can be made: 1) for Border Privet, both the young
twigs and stalks of the floral panicles are conspicuously
hairy, while for Common Privet they are hairless or minutely pubescent,
2) the floral panicles of Border Privet are 1-2" in length, while those
of Common Privet are usually longer, and 3) the corolla lobes of Border
Privet are about one-half the length of its corolla tubes, while the
corolla lobes of Common Privet are about the same length as its
corolla tubes. However, this last distinction may not be reliable in
all cases because of the variations that exist within these two
species.
Another species that is sometimes cultivated, Chinese Privet (
Ligustrum sinense),
has escaped in other areas of the United States, although
apparently not in Illinois. Chinese Privet can be distinguished from
the preceding two species by the strongly exerted stamens of its
flowers; its anthers extend beyond the tips of the corolla lobes. The
anthers of Border Privet and Common Privet, in
contrast, extend only to the base, or a little beyond the base, of
their corolla lobes.