Description:
This small deciduous shrub is ½-2' tall with spreading leafy branches.
The trunk and branches of older shrubs are often woody with
shredded bark, while young shoots and twigs are green to brownish
red, terete, and finely warty. Sometimes the twigs and shoots are
slightly
short-pubescent. Alternate leaves along the twigs and shoots are ¾-1½"
long and about ¼-¾" across; they are elliptic in shape and very finely
serrated along their margins. Both the upper and lower surfaces of the
leaves are medium to dark green and glabrous (or nearly so). The
short petioles are up to 1/8" (3 mm.) in length.
Small clusters of
nodding flowers develop from the preceding year's twigs. Each flower is
about ¼" long and a little less across, consisting of a short green
calyx with 5 teeth, a short-tubular corolla that is white or
pinkish white, 10 inserted stamens, and an inferior ovary with a single
style. The corolla is slightly indented along its upper rim, where 5
tiny lobes occur that are recurved. The peduncle and pedicels of
the clustered flowers are light green to reddish brown and glabrous.
The blooming period occurs from late spring to early summer for
about 3 weeks. Afterwards, fertile flowers are replaced by globoid
berries up to 1/3" (8 mm.) across that become dark blue with a whitish
bloom at maturity. At this time, the fleshy interior of each berry is
juicy and sweet and it typically contains 10-15 tiny seeds. The root
system is
usually shallow and spreading, although a taproot may develop on an
older shrub. Vegetative colonies are produced from underground
runners. The deciduous leaves often become red or burgundy during the
the autumn.
Cultivation:
The preference is full sun to light
shade, mesic to dry conditions, and an acidic soil that is sandy.
Cross-pollination between genetically distinct shrubs increases the
production of fruit. This shrub may fail to produce flowers and fruit
in areas that are too shady.
Range
& Habitat: The native
Lowbush Blueberry is occasional in NE Illinois (see
Distribution
Map).
Habitats include sand prairies, shrub prairies, sandy savannas,
sandy woodlands, rocky upland woodlands, rocky bluffs, sand dunes along
Lake Michigan, and bogs. Lowbush Blueberry is sometimes the dominant
understory shrub in some of these habitats, especially when they are
sandy. This shrub becomes more abundant in response to occasional
wildfires and the openings that such wildfires create.
Faunal
Associations: The flowers are cross-pollinated primarily
by various
bees, including Andrenid bees (
Andrena
spp.), bumblebees, and
honeybees. Both nectar and pollen are available as floral rewards. The
pollen is released from the anthers in response to the "buzz
pollination" of the bees (high frequency vibration of the thoracic
muscles). In addition to these floral visitors, many insects feed on
the foliage, stems, and other parts of blueberry shrubs. For example,
the larvae of two beetles,
Oberea
myops (Rhododendron Stem Borer)
and
Oberea tripunctata
(Dogwood Twig Borer), bore through the twigs of
these shrubs, while the larvae of two flies,
Dasineura cyanococci
and
Dasineura oxycoccum
(Blueberry Gall Midge), form galls on the buds
or developing flowers. Other insect feeders include the leaf beetles
Altica sylvia
and
Tricholochmea
vaccinii, the larvae of
Rhagoletis
mendax (Blueberry Fruit Fly),
Clastoptera saintcyri
(Heath Spittlebug),
Limotettix vaccinii
(Blunt-Nosed Leafhopper), and
Mesolecanium
nigrofasciatum (Terrapin Scale). The caterpillars of two
butterflies,
Callophrys augustinus
(Brown Elfin) and
Callophrys
henrici (Henry's
Elfin), feed on the flowers and developing fruits of blueberry shrubs.
In addition to these insects, the caterpillars of such moths as
Hemaris gracilis
(Slender Clearwing),
Sympistis
dentata
(Blueberry Cinder), and
Xestia dilucida
(Reddish Heath Dart) also feed on these shrubs. The
Insect Table has a more complete list of these insect feeders. Blueberry
fruits are an important source of food to many vertebrate animals.
These species include the terrestrial turtles,
Clemmys insculpta
(Wood Turtle) and
Terrapene
carolina (Eastern Box Turtle); such birds as the
Ruffed Grouse, Wild Turkey, Blue Jay, American Robin, Yellow-Breasted
Chat, Wood Thrush, and Eastern Bluebird (see the
Bird Table
for a more
complete list of these species); and such mammals as the American Black
Bear, American Red
Fox, Gray Fox, Striped Skunk, Franklin's Ground Squirrel, Fox Squirrel,
Least Chipmunk,
Woodland Jumping Mouse, Deer Mouse, and White-Footed Mouse (Ernst et
al., 1994; Martin et al., 1951/1961; Hamilton, 1941; Haugen, 1942;
Schmidt, 1931; Beeman & Pelton, 1980; Mosnier et al., 2008; Romain
et al., 2013; Noyce & Coy, 1990). In addition to the
fruits, the White-Tailed Deer and Cottontail Rabbit also browse on the
foliage and twigs. Because Lowbush Blueberry is a densely branched
shrub that often forms large colonies, it provides significant
protective cover for ground-nesting birds and other wildlife, including
the endangered Kirtland's Warbler.
Photographic
Location: A sandy woodland near
Lake Michigan at the Indiana Dunes State Park in NW Indiana.
Comments:
Lowbush
Blueberry (
Vaccinium
angustifolium) is one of the primary sources of
commercial blueberries, particularly in the New England region of the
United States. The flavor of the berries is sweet and mild.
Because this shrub is somewhat variable across its range,
different varieties have been described, although none of these are
currently recognized in Illinois. Compared to the Hillside Blueberry
(
Vaccinium pallidum),
Lowbush Blueberry has more narrow leaves and
its leaf undersides are less pale. It differs from another species,
Canada Blueberry (
Vaccinium
myrtilloides), by having leaf
undersides that are glabrous, rather than pubescent. These species
usually occupy drier habitats than the taller Highbush Blueberry
(
Vaccinium corymbosum);
the latter is typically found in forested bogs
and similar wet habitats.