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• Physocarpus opulifolius

Physocarpus opulifolius — Atlantic ninebark

Facts

Atlantic ninebark is a graceful shrub with arching branches that grows from 2 to 8 feet (2.5 m) tall. A member of the rose family closely related to steeplebush (Spiraea spp.), it produces masses (corymbs) of delicate, pinkish-white flowers in May and June. Its peeling, brown bark gives it its common name and also much visual interest during the winter. This tough shrub can tolerate a variety of clayey to droughty soils.

Habitat

Anthropogenic (man-made or disturbed habitats), floodplain (river or stream floodplains), forest edges, forests, shores of rivers or lakes

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

  Superposed buds

  there are no superposed buds on the branch

• Flowers

  Carpels fused

  the carpels are fused to one another

  Enlarged sterile flowers

  there are no enlarged sterile flowers on the plant

  Flower petal color

  • pink
  • 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 type

  the inflorescence is a corymb (with long lower branches and shorter upper branches, giving it a more or less flat-topped look)

  Number of pistils

  • 1
  • 2
  • 3
  • 4
  • 5

  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 cilia (Ilex)

  NA

  Stamen number

  13 or more

• Fruits or seeds

  Berry color

  NA

  Fruit type (general)

  the fruit is dry and splits open when ripe

  Fruit type (specific)

  • the fruit is a follicle (has one ovary that splits along one side to release the seeds)
  • 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 upper side of leaf blade

  • the upper side of the leaf is fuzzy or hairy
  • 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 cuneate (wedge-shaped, tapers to the base with relatively straight, converging edges), or narrow
  • the base of the leaf blade is truncate (ends abruptly in a more or less straight line as though cut off)

  Leaf blade edges

  • the edge of the leaf blade has lobes, or it has both teeth and lobes
  • 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

  at least some of the hairs on the leaf blade are branched

  Leaf blade length

  20–70 mm

  Leaf blade scales

  there are no scales on the leaf blades

  Leaf blade shape

  • the leaf blade is orbicular (roughly circular, as wide as long)
  • the leaf blade is ovate (widest below the middle and broadly tapering at both ends)

  Leaf blade texture

  the leaf blade is herbaceous (has a leafy texture)

  Leaf blade width

  40–70 mm

  Leaf duration

  the leaves drop off in winter (or they wither but persist on the plant)

  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 teeth

  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 simple (lobed or unlobed but not separated into leaflets)

  Leaves per node

  there is one leaf per node along the stem

  Specific leaf type

  the leaves are simple (lobed or unlobed but not separated into leaflets

• Place

  Habitat

  terrestrial

  New England state

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

  Specific habitat

  • edges of forests
  • forests
  • man-made or disturbed habitats
  • river or stream floodplains
  • shores of rivers or lakes

• 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 peels off easily or hangs off

  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)

  NA

  Twig papillae (Vaccinium species only)

  NA

  Twig winter color

  • brown
  • gray
  • red

  Wings on branch

  the branch does not have wings on it

  armature on plant

  the plant does not have spines, prickles, or thorns

Wetland status

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

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae