blackberry (Rubus allegheniensis)
Rubus allegheniensis Porter var. plausus L.H. Bailey
Rubus allegheniensis Porter var. populifolius Fernald
Rubus attractus L.H. Bailey
Rubus auroralis L.H. Bailey
Rubus fissidens L.H. Bailey
Rubus longissimus L.H. Bailey
Rubus nigrobaccus L.H. Bailey
Rubus nuperus L.H. Bailey
Rubus pennus L.H. Bailey
Rubus rappii L.H. Bailey
Rubus separ L.H. Bailey
CONFIRMATION STATUS: Confirmed.
TAXONOMY: The currently accepted scientific name of common black-
berry is Rubus allegheniensis Porter. There are two varieties of Rubus
allegheniensis occurring in Virginia: 1) variety allegheniensis, and 2)
gravesii Fernald. The Atlas of Virginia Flora lists Rubus allegheniensis
without variety designation. Variety allegheniensis is described.
It can be difficult to tell the different Rubus species apart. The fruits of
common blackberry tend to be a bit larger and more elongated than those
of other blackberries, and they usually have an excellent flavor. This black-
berry is distinguished from other blackberries by the numerous glandular
hairs on the peduncles and pedicels of its elongated racemes of flowers.
Furthermore, its mature leaflets are usually no more than twice as long
as they are wide.
NATIVE STATUS: Native, United States and Canada.
GENERAL BOTANICAL CHARACTERISTICS: This native woody
shrub forms canes that are initially erect, but often bend downward to
re-root in the ground. These canes actively grow and form leaves during
the first year, and develop fruits in the form of drupes during the second
year, afterwhich they die down. The canes are about 3-6' tall; they are
green where there is new growth at the tips, otherwise they are brown
or reddish brown with stout prickles that are straight or somewhat curved.
The alternate leaves are usually trifoliate or palmately compound; they
have long petioles. The leaflets are up to 4" long and 3" across; they are
up to twice as long as wide. A typical leaflet is usually ovate with coarse,
doubly serrate margins; it may have a few scattered white hairs on the
upper surface, while the lower surface is light green and pubescent. The
canes develop racemes with about 12 white flowers; these racemes are
much longer than they are wide. There are conspicuous glandular-tipped
hairs on the peduncles and pedicels of the inflorescence. A flower has 5
white petals and 5 green sepals with pointed tips; this flower is about ¾-1"
across. The petals are longer than the sepals, rather rounded, and often
wrinkly. In the center of each flower, are numerous stamens with yellow
anthers surrounding a green reproductive structure with a prickly appear-
ance. There is little or no floral fragrance. The drupes develop later in the
summer; they are about ¾" long and 1/3" across, although their size varies
with moisture levels. The drupes are initially white or green, but eventually
turn red, finally becoming almost black. They are seedy and have a sweet
flavor when fully ripened. The root system consists of a taproot. This plant
often forms loose colonies vegetatively.
REGENERATION PROCESS: Common blackberry propogates itself
by reseeding and, to a limited extend, through vegetative reproduction.
SITE CHARACTERISTICS: Common blackberry prefers light shade
to full sun, and mesic conditions; some drought is tolerated, although
this can reduce the size of the drupes. Growth is best in rich fertile soil;
a clay-loam or rocky soil is also acceptable.
SUCCESSIONAL STATUS: Common blackberry is prolific in early suc-
cessional stages. It is generally found in abandoned or disturbed areas,
and is less common in mid- to late successional stages of forest growth.
Like other members of Rubus genus, it is often "marginally "associated
with forest growth, perferring peripheral locations.
SEASONAL DEVELOPMENT: The flowers bloom during late spring or
early summer for a month.
GENERAL DISTRIBUTION: Common blackberry is primarily found
in the eastern United States and Canada. It ranges from Georgia north to
the maritime provinces of Canada (except Newfoundland), and extends
west through the Ohio Valley and into the eastern portion of the Great
Plains. It is not naturally found in the lower Mississippi Gulf coast, south-
west, Rocky Mountain region, and most of the Pacific Northwest. It does
occur in California and British Columbia.
SKY MEADOWS DISTRIBUTION:
Shrub 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: Habitats include
moist to slightly dry prairie edges along woodlands, thickets, open wood-
lands, savannas, woodland meadows, limestone glades, fence rows, areas
along roadsides and railroads, and abandoned pastures. This plant favors
disturbed, burned-over areas in and around woodlands; it is one of the
shrubby invaders of prairies.
IMPORTANCE AND USES: The nectar and pollen of the flowers attract
many kinds of insects, especially long-tongued and short-tongued bees.
This includes honeybees, bumblebees, Little Carpenter bees, Nomadine
Cuckoo bees, Mason bees, Green Metallic bees and other Halictid bees,
and Andrenid bees. Other visitors of the flowers include wasps, flies, small
to medium-sized butterflies, skippers, and beetles. Many of the flies and
beetles feed on pollen and are not very effective at pollination. The cater-
pillars of the butterfly Satyrium liparops strigosum (striped hairstreak)
and several species of moths feed on the common blackberry. Also, vari-
ous upland gamebirds, songbirds, and mammals feed on the fruit, stems,
or foliage of this plant. Among the upland gamebirds, the greater prairie
chicken, wild turkey, bobwhite, and ring-necked pheasant have been
observed eating the drupes of blackberries. These various animals help to
distribute the seeds far and wide. The common blackberry provides some
shelter and shrubby protection to various ground-nesting birds and small
mammals, such as the cottontail rabbit. In general, the ecological value of
blackberries is very high.
The fruit can be eaten raw, cooked or dried for later use; its taste has been
described as pleasantly sweet and with a somewhat spicy flavour.
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