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Rubus pensilvanicus — Pennsylvania blackberry

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Facts

Pennsylvania blackberry has oval terminal leaflets on the first-year stems and short (2-4 mm or 1/4 inch long), sparse prickles. The fruits of Pennsylvania blackberry are edible.

Habitat

Anthropogenic (man-made or disturbed habitats), forest edges, meadows and fields, swamps

New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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Characteristics

Habitat
  • terrestrial
  • wetlands
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont
Growth form
the plant is a shrub (i.e., a woody plant with several stems growing from the base)
Leaf type
the leaf blade is compound (i.e., made up of two or more discrete leaflets
Leaves per node
there is one leaf per node along the stem
Leaf blade edges
the edge of the leaf blade has teeth
Leaf duration
the leaves drop off in winter (or they wither but persist on the plant)
armature on plant
the plant has spines, prickles, or thorns
Leaf blade length
110–220 mm
Leaf blade width
110–220 mm
Leaf stalk
the leaves have leaf stalks
Fruit type (general)
the fruit is fleshy
Bark texture
the bark of an adult plant is thin and smooth
Twig winter color
  • brown
  • gray
Bud scale number
there are three or more scales on the winter bud, and they overlap like shingles, with one edge covered and the other edge exposed
Show all characteristics

  • Buds or leaf scars

    Bud scale number
    there are three or more scales on the winter bud, and they overlap like shingles, with one edge covered and the other edge exposed
    Bud scar shape (Fraxinus)
    NA
    Collateral buds
    there are no collateral buds on the sides of the branches
    Leaf scar arrangement
    there is one leaf scar per node on the stem or twig
    Superposed buds
    there are no superposed buds on the branch
    Winter bud stalks
    the winter buds have no stalks

  • Flowers

    Carpels fused
    • the carpel is solitary or (if 2 or more) the carpels are not fused to one another
    • the carpels are fused to one another
    Enlarged sterile flowers
    there are no enlarged sterile flowers on the plant
    Flower petal color
    white
    Flower symmetry
    there are two or more ways to evenly divide the flower (the flower is radially symmetrical)
    Hairs on ovary (Amelanchier)
    NA
    Hypanthium present
    the flower has a hypanthium
    Inflorescence hairs
    there are hairs on some part of the inflorescence
    Inflorescence type
    the inflorescence is a raceme (a long unbranched stem with stalked flowers growing along it)
    Number of pistils
    6 or more
    Ovary position
    the ovary is above the point of petal and/or sepal attachment
    Petal and sepal arrangement
    the flower includes two cycles of petal- or sepal-like structures
    Petal appearance
    the petals are thin and delicate, and pigmented (colored other than green or brown)
    Petal fusion
    the perianth parts are separate
    Sepal appearance
    the sepals resemble leaves in color and texture
    Sepal cilia (Ilex)
    NA
    Sepal tip glands
    there are no glands at the tips of the sepal lobes
    Sepals fused only to sepals
    the sepals are separate from one another
    Stamen number
    13 or more
    Stamens fused
    the stamens are not fused to one another

  • Fruits or seeds

    Berry color
    • NA
    • black
    Fruit tissue origin
    there are no flower parts that form part of the fruit
    Fruit type (general)
    the fruit is fleshy
    Fruit type (specific)
    • the fruit is a berry (fleshy, with the wall enclosing one or more sections, with two or more seeds)
    • the fruit is a drupe (fleshy, with a firm inner ovary wall that encloses a single seed)
    • the fruit is an aggregate (composed of multiple fused ovaries from one flower)
    Nut with spines (Fagaceae)
    NA
    Wings on fruit
    there are no wings on the fruit

  • Glands or sap

    Sap color
    the sap is clear and watery
    Stalked glands on fruit (Rosa)
    NA

  • Growth form

    Growth form
    the plant is a shrub (i.e., a woody plant with several stems growing from the base)

  • Leaves

    Hairs on underside of leaf blade
    the underside of the leaf has hairs on it
    Hairs on upper side of leaf blade
    the upper side of the leaf is not hairy, or has very few hairs
    Leaf blade base shape
    • The base of the leaf blade is cordate (heart-shaped, with rounded lobes)
    • the base of the leaf blade is cuneate (wedge-shaped, tapers to the base with relatively straight, converging edges), or narrow
    • the base of the leaf blade is rounded
    Leaf blade base symmetry
    the leaf blade base is symmetrical
    Leaf blade bloom
    the underside of the leaf has no noticeable bloom
    Leaf blade edges
    the edge of the leaf blade has teeth
    Leaf blade edges (Acer)
    NA
    Leaf blade flatness
    the leaf is flat (planar) at the edges
    Leaf blade hairs
    the hairs on the leaf blade are different from the choices given
    Leaf blade length
    110–220 mm
    Leaf blade scales
    there are no scales on the leaf blades
    Leaf blade shape
    • the leaf blade is elliptic (widest near the middle and tapering at both ends)
    • the leaf blade is obovate (egg-shaped, but with the widest point above the middle of the leaf blade)
    • the leaf blade is ovate (widest below the middle and broadly tapering at both ends)
    • the leaf blade is rhombic (roughly diamond-shaped)
    Leaf blade texture
    the leaf blade is herbaceous (has a leafy texture)
    Leaf blade translucent dots
    there are no translucent dots on the leaf blade
    Leaf blade vein pattern
    the main veins of the leaf blade are pinnate (the secondary veins branch off at intervals from the main central vein) and non-arcuate (not arched towards the leaf tip)
    Leaf blade veins
    the leaf blade has one main vein running from the base toward the tip
    Leaf blade width
    110–220 mm
    Leaf duration
    the leaves drop off in winter (or they wither but persist on the plant)
    Leaf form
    the plant is broad-leaved (with broadly flattened leaf blades)
    Leaf lobe tips (Quercus)
    NA
    Leaf midrib glands
    the midrib of the leaf blade lacks glands on the upper surface
    Leaf stalk
    the leaves have leaf stalks
    Leaf stalk attachment to leaf
    the petiole attaches at the basal margin of the leaf blade
    Leaf stalk nectaries
    there are no nectaries on the leaf stalk
    Leaf stalk shape
    the leaf stalk is not flattened
    Leaf teeth
    • the leaf blade margin has teeth, which themselves have smaller teeth on them
    • the leaf blade margin is serrate (with forward-pointing) or dentate (with outward-pointing) with medium-sized to coarse teeth
    Leaf teeth hairs (Carya)
    NA
    Leaf type
    the leaf blade is compound (i.e., made up of two or more discrete leaflets
    Leaves per node
    there is one leaf per node along the stem
    Specific leaf type
    • the leaf is compound, with three leaflets
    • the leaf is palmately compound with more than three leaflets
    Stipules
    the plant has stipules

  • Place

    Habitat
    • terrestrial
    • wetlands
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • edges of forests
    • man-made or disturbed habitats
    • meadows or fields
    • swamps

  • Scent

    Plant odor
    the plant does not have much of an odor, or it has an unpleasant or repellant odor

  • Stem, shoot, branch

    Aerial roots
    the plant has no aerial roots
    Bark texture
    the bark of an adult plant is thin and smooth
    Branch brittleness (willows only)
    NA
    Branch cross-section
    the branch is circular in cross-section, or it has five or more sides, so that there are no sharp angles
    First-year cane (Rubus)
    the first year cane stems are upright or arching
    Lenticels on twigs
    there are no lenticels on the twigs, or they are very hard to see
    Pith shape
    the outline of the pith in a twig is roughly round
    Short shoots
    there are no peg- or knob-like shoots present
    Twig bloom
    there is no bloom on the twig
    Twig papillae (Vaccinium species only)
    NA
    Twig scales
    there are no scales on the twig surface
    Twig winter color
    • brown
    • gray
    Wings on branch
    the branch does not have wings on it
    armature on plant
    the plant has spines, prickles, or thorns

Wetland status

Usually occurs in non-wetlands, but occasionally in wetlands. (Wetland indicator code: FACU)

In New England

Distribution

Connecticut
present
Maine
present
Massachusetts
present
New Hampshire
present
Rhode Island
present
Vermont
present

Conservation status

Exact status definitions can vary from state to state. For details, please check with your state.

Massachusetts
widespread (S-rank: S5)

From Flora Novae Angliae dichotomous key

22.  Rubus pensilvanicus Poir. N

Pennsylvania blackberry. Rubus abactus Bailey; R. amnicola Blanch.; R. andrewsianus Blanch.; R. avipes Bailey; R. barbarus Bailey; R. conanicutensis Bailey; R. facetus Bailey; R. honorus Bailey; R. insons Bailey; R. orarius Blanch.; R. ostryifolius Rydb.; R. pergratus Blanch.; 
 R. philadelphicus Blanch. • CT, MA, ME, NH, RI, VT. Fields, roadsides, forest borders, swamps, 
open rights-of-way.

1×22. Rubus allegheniensis × Rubus pensilvanicus → This rare blackberry hybrid is known from CT, MA, ME, NH, RI. It is marked by stems with scattered, relatively short and thin prickles (compared with Rubus allegheniensis) and an inflorescence with occasional stipitate-glands. Tentative synonyms: Rubus alumnus Bailey; R. licitus Bailey; R. paulus Bailey.

5×22. Rubus canadensis × Rubus pensilvanicus → This rare blackberry hybrid is known from ME, NH. It is marked by stems with sparse, thin prickles that number 0–7 per 10 cm. The leaves closely resemble those of Rubus canadensis but have sparse to moderate pubescence abaxially. The raceme axis is densely (rarely only moderately) pubescent.

11×22. Rubus enslenii × Rubus pensilvanicus → This very rare blackberry hybrid is known from NH. It is marked by primocanes with arched to trailing habit, primocane leaflets numbering 3–5 and sparsely pubescent abaxially, stems with sparse, thin, slender prickles, 1- to 5-flowered inflorescences up to 8 cm long, and pedicels 2–6 cm long that lack stipitate-glands.

22×25. Rubus pensilvanicus × Rubus recurvicaulis → This rare blackberry hybrid is known from ME, NH. It is marked by low-doming primocanes that are armed with relatively slender, straight to slightly curved prickles, leaflets that are sparsely pubescent abaxially, and a variable inflorescence (but always without stipitate-glands).

22×28. Rubus pensilvanicus × Rubus vermontanus → This rare blackberry hybrid is known from ME. It is marked by erect to arching primocanes with numerous small-based prickles (ca. 200 per 10 dm), and lacking stipitate-glands with relatively glabrous abaxial leaf blade surface, and with short racemes (2.5–5 cm long) that lack stipitate-glands. Tentative synonyms: Rubus miscix Bailey; R. peculiaris Blanch.

Native to North America?

Yes and no (some introduced)

Sometimes confused with

Rubus elegantulus:
lower leaflet surface lacking hairs or with hairs only on the primary veins (vs. R. pensilvanicus, with the lower leaflet surface evidently hairy).
Rubus allegheniensis:
axis of inflorescence with stipitate glands and inflorescence with usually 9-22 flowers (vs. R. pensilvanicus, with the axis of inflorescence lacking stipitate glands and inflorescence with usually 7-12 flowers).
Rubus frondosus:
prickles of the stem mostly 4–6 mm long, numbering 4–60 per 10 cm, leaf blades tending to be more chartaceous, and inflorescence with mostly 1–7 leafy bracts (vs. R. pensilvanicus, with prickles of the stem mostly 2–4 mm long, numbering 0–20 per 10 cm, leaf blades herbaceous, and inflorescence with mostly 1 or 2 leafy bracts).

Synonyms

  • Rubus abactus Bailey
  • Rubus amnicola Blanch.
  • Rubus andrewsianus Blanch.
  • Rubus avipes Bailey
  • Rubus barbarus Bailey
  • Rubus conanicutensis Bailey
  • Rubus facetus Bailey
  • Rubus honorus Bailey
  • Rubus insons Bailey
  • Rubus orarius Blanch.
  • Rubus ostryifolius Rydb.
  • Rubus pergratus Blanch.
  • Rubus philadelphicus Blanch.

Family

Rosaceae

Genus

Rubus