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• Acer rubrum

Acer rubrum — red maple

Facts

Red maple takes its common name from its reddish buds that swell in spring, its red leaf petioles in summer, and its brilliant red foliage in fall. Although it grows largest in and near swamps, it abounds in New England forests and is becoming more common as sugar maple begins to succumb to climatic change. It grows rapidly and stump-sprouts readily. Although the wood can be used for veneer and a variety of small products such as boxes and clothespins, it is weaker and harder to work than sugar maple. Red maple also yields a sugary syrup, but in smaller quantities than sugar maple. As an early-successional forest tree, however, it provides browse for moose and many other mammals.

Habitat

Forest edges, forests, meadows and fields, shores of rivers or lakes, swamps, wetland margins (edges of wetlands), woodlands

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

  Bundle scar number

  3

  Collateral buds

  • the branches have collateral buds on them
  • there are no collateral buds on the sides of the branches

  Leaf scar arrangement

  there are two leaf scars per node on the stem or twig

  Superposed buds

  there are no superposed buds on the branch

  Winter bud scale hairs

  the winter bud scales have no hairs on them

  Winter bud scales

  the winter bud is perulate (partially or completely covered with one or more scales)

  Winter bud shape

  • the winter buds are lanceoloid (lance-shaped, widest below the middle and tapering to the ends)
  • the winter buds are ovoid (egg-shaped)

  Winter bud stalks

  • the winter buds have no stalks
  • the winter buds have short stalks

• 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

  red

  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 does not have a hypanthium

  Inflorescence type

  • the inflorescence differs from the choices given
  • the inflorescence is a fascicle (compact cluster of flowers)
  • the inflorescence is an umbel (with an axis so short it appears the flowers all originate from the same point)

  Number of pistils

  1

  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 petals 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

  • 10
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9

  Stamens fused

  the stamens are not fused to one another

• 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 schizocarp (when dry it splits into sections, each holding one or more seeds)
  • the fruit is an achene (dry, usually 1-seeded, does not separate or split open at maturity)

  Nut with spines (Fagaceae)

  NA

  Wings on fruit

  the fruit has one or more wings on it

• 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 tree

• Leaves

  Hairs on underside of leaf blade

  • the underside of the leaf has hairs on it
  • the underside of the leaf has no hairs

  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)

  Leaf blade base symmetry

  the leaf blade base is symmetrical

  Leaf blade bloom

  there is a noticeable powdery or waxy bloom on the underside of the leaf

  Leaf blade edges

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

  Leaf blade edges (Acer)

  the leaves have teeth throughout the leaf blade, including between the lobes

  Leaf blade flatness

  the leaf is flat (planar) at the edges

  Leaf blade hairs

  • NA
  • the hairs on the leaf blade are different from the choices given

  Leaf blade length

  60–100 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)
  • the leaf blade is triangular, with the stalk or attachment point on one of the sides

  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 palmate (radiate out from the base, like a hand)

  Leaf blade veins

  the leaf blade has three or more main veins running from the base (or near the base) towards the tip

  Leaf blade width

  60–150 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 is crenate (with rounded teeth) or crenulate (with tiny, rounded 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 (i.e., lobed or unlobed but not separated into leaflets)

  Leaves per node

  there are two leaves per node along the stem

  Specific leaf type

  the leaves are simple (i.e., lobed or unlobed but not separated into leaflets

  Stipules

  there are no stipules on the plant, or they fall off as the leaf expands

• Place

  Habitat

  • terrestrial
  • wetlands

  New England state

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

  Specific habitat

  • edges of forests
  • edges of wetlands
  • forests
  • meadows or fields
  • shores of rivers or lakes
  • swamps
  • woodlands

• 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 ridged or plated
  • 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)

  NA

  Lenticels on twigs

  there are clearly lenticels on the twigs

  Pith shape

  the outline of the pith in a twig is roughly round

  Pith type

  the pith inside the twig is solid, completely filled with spongy tissue

  Short shoots

  there are no peg- or knob-like shoots present

  Twig bloom

  there is no bloom on the twig

  Twig hairs

  the twigs have few or no hairs on them

  Twig papillae (Vaccinium species only)

  NA

  Twig scales

  there are no scales on the twig surface

  Twig winter color

  • 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

Occurs in wetlands or non-wetlands. (Wetland indicator code: FAC)

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae