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- Rubus pensilvanicus
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
Native: indigenous.
Non-native: introduced (intentionally or unintentionally); has become naturalized.
County documented: documented to exist in the county by evidence (herbarium specimen, photograph). Also covers those considered historical (not seen in 20 years).
State documented: documented to exist in the state, but not documented to a county within the state. Also covers those considered historical (not seen in 20 years).
Note: when native and non-native populations both exist in a county, only native status is shown on the map.
Found this plant? Take a photo and post a sighting.
Characteristics
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Growth form
- the plant is a shrub (a woody plant with several stems growing from the base)
- Leaf type
- the leaf blade is compound (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
-
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 (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 (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
- unranked (S-rank: SNR)
- Massachusetts
- unrankable (S-rank: SU)
var. pergratus
- Massachusetts
- unranked (S-rank: SNR)
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
Sometimes confused with
- 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 canadensis: lower leaflet surface lacking hairs or with hairs only on the primary veins (vs. R. pensilvanicus, with the lower leaflet surface evidently hairy). Rubus elegantulus: lower leaflet surface lacking hairs or with hairs only on the primary veins (vs. lower leaflet surface evidently hairy). Rubus frondosus: prickles of the stem usually 4-6 mm long and numbering 4-60 per 10 cm of stem (vs. prickles of the stem usually 2-4 mm long and numbering 0-20 per 10 cm of stem).
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.