black raspberry (Rubus occidentalis)
black cap raspberry
Rubus occidentalis L. var. pallidus L.H. Bailey
CONFIRMATION STATUS: Confirmed.
TAXONOMY: The currently accepted scientific of black raspberry
is Rubus occidentalis L.
While both raspberries and blackberries are members of the same genus,
the drupes of raspberries detach cleanly and easily from their receptacles,
while the drupes of blackberries do not. Other native raspberries produce
drupes that are red at maturity, rather than black-purple. When drupes
are unavailable for observation, Black Raspberry can be identified by the
following features: 1) The white petals of the flowers are narrow, rather
than broad and overlapping, 2) the compound leaves are usually trifoliate,
rather than palmate with 5 or more leaflets, 3) the leaflets are white
tomentose on their undersides, rather than some shade of green, and 4)
young vegetative canes often have a white bloom that can be rubbed off
(i.e., they are glaucous).
NATIVE STATUS: Native, United States and Canada.
GENERAL BOTANICAL CHARACTERISTICS: This native perennial
shrub produces little-branched canes up to 6' long during the first year.
These canes are initially erect, but they eventually arch sideways and
downward – their tips sometimes reach the ground. First-year canes are
vegetative and do not produce flowers and fruit. They are initially green,
hairless, and glaucous, but later turn brown and woody during the winter.
Scattered along the length of each cane are prickles that are short and
curved. During the second year, these canes develop short branches that
terminate in erect cymes or short racemes of flowers. Along the length of
these canes, there are alternate compound leaves. These compound leaves
are usually trifoliate; rarely are they palmate with 5 leaflets. The leaflets
are up to 3" long and 2" across. They are cordate-ovate or ovate in shape
and doubly serrate along the margins; some leaflets may be shallowly cleft.
The upper surface of each leaflet has strong pinnate venation, while its
lower surface is white tomentose (covered with white hairs that are very
short and appressed). The terminate leaflet has a short slender petiole,
while the lateral leaflets are sessile, or nearly so. The flowers are bunched
tightly together on the cymes/racemes. Each flower is about ½" across,
consisting of 5 white petals, 5 green sepals, and numerous stamens that
surround the multiple green carpels and their styles. The petals are elliptic
or oblong, while the sepals are triangular-shaped and spreading; the petals
are about the same length as the sepals. Each flower is replaced by a com-
pound drupe that is ovoid and about 1/3" long when fully mature. This
compound drupe is initially white, later becomes red, and finally turns
black-purple when it is mature. Each drupe consists of multiple drupelets,
each drupelet containing a single seed. The fleshy drupes are sweet and
slightly tart in flavor; they detach cleanly and easily from their receptacles.
The root system consists of a woody branching taproot. Vegetative offsets
are often produced by the canes rooting at their tips.
REGENERATION PROCESS: Black raspberry propogates itself by
reseeding and, to a limited extent, by vegetative reproduction.
SITE CHARACTERISTICS: Black raspberry prefers partial sun, moist
to mesic conditions, and rich loamy soil. In areas that are too sunny and
dry, the fruit may not develop properly without adequate rain. The canes
also fail to set fruit if there is too much shade. Prefers open, undisturbed
habitats such as fields, thickets, clearings, ravine flats, along hillsides, and
in open woods. It lives in both dry and moist areas, along roadsides, rocky
sites, and fence rows.
SUCCESSIONAL STATUS: Like other members of the Rubus genus,
black raspberry is usually associated with initial to mid- successional
conditions, and less frequently with more mature successional situations.
It preference for disturbed areas and "marginal" or opened woodland
conditions makes it less likely to be found in mature forest growths.
SEASONAL DEVELOPMENT: The blooming period occurs during the
late spring or very early summer and lasts about 2-3 weeks.
GENERAL DISTRIBUTION: Black raspberry is primarily found in the
eastern United States and Canada, ranging from Georgia north through
New England and into eastern Canada (excepting Nova Scotia and New-
foundland). It extends west through the Ohio Valley and into the Great
Plains, stopping at the Rocky Mountain region. Less common in Gulf Coast
states, it does not naturally occur in the southwest, far Pacific west and
northwest, or throughout most of the Rocky Mountain states (it has been
introduced into Colorado). In Canada it extends as far west as Ontario.
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
openings in deciduous woodlands, woodland borders, savannas, thickets,
fence rows, overgrown vacant lots, powerline clearances in wooded areas,
and partially shaded areas along buildings. Black raspberry adapts well
to human-related disturbance; it also occurs in higher quality natural areas.
IMPORTANCE AND USES: The nectar of the flowers attracts bees
primarily, including honeybees, bumblebees, Mason bees, Leaf-Cutting
bees (Megachile spp.), Cuckoo bees (Nomadine), Halictid bees, and
Andrenid bees. The short-tongued bees also collect pollen from the
flowers. Less often, small butterflies and skippers may visit the flowers
for nectar. Because raspberries are economically important, insects that
feed on the foliage, stems, and fruit are fairly well known. Insects that
chew on the foliage or suck sap include caterpillars of various moths,
spider mites and flea beetles, and leafhoppers. Insects that bore through
canes or roots include the caterpillars of some moths and grubs of various
wood-boring beetles. The fruit of both raspberries and blackberries is an
important source of food for many upland gamebirds and songbirds. Rac-
coons, fox squirrels, and chipmunks occasionally eat the fruit, while rabbits
and deer browse on the foliage and stems.
The Kiowa and Apache made a tea from the roots of Rubus species to
treat stomach ache. Blackberry root tea was also part of the traditional
pharmacopea for treatment of hemorrhaging and hemophilia. In the south,
blackberry tea was mixed with whiskey to expel gas. The juice of raspberry
fruits was used to flavor medicines.
While the flowers of black raspberry are not very showy, the fruit has
excellent flavor and is rather colorful.
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