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- Platanus occidentalis
Platanus occidentalis — American sycamore
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Facts
American sycamore is a handsome tree with a patterned white-gray bark that flakes off to reveal a green inner bark. It can attain an enormous girth, especially in its native habitats in floodplains. One tree measured by George Washington was 13 feet (3.5m) in diameter. Old sycamores often have hollow trunks, which provide shelter to flocks of chimney swifts and even denning sites for black bear. Cross-sections of fat trunks were used as early cart wheels by pioneer settlers. Sycamore is also widely planted as a majestic street tree, although it is susceptible to injury from ozone and other pollutants.
Habitat
Floodplain (river or stream floodplains), shores of rivers or lakes, 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.
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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 tree
- Leaf type
- the leaf blade is simple (i.e., lobed or unlobed but not separated into leaflets)
- Leaves per node
- there is one leaf per node along the stem
- Leaf blade edges
- the edge of the leaf blade has lobes, or it has both teeth and lobes
- Leaf duration
- the leaves drop off in winter (or they wither but persist on the plant)
- armature on plant
- the plant does not have spines, prickles, or thorns
- Leaf blade length
- 50–200 mm
- Leaf blade width
- 50–250 mm
- Leaf stalk
- the leaves have leaf stalks
- Fruit type (general)
- the fruit is dry but does not split open when ripe
- Bark texture
- the bark of an adult plant peels off easily or hangs off
- Twig winter color
-
- brown
- gray
- orange
- Bud scale number
- there is one scale on the winter bud, and it covers the scale like a cap
-
Buds or leaf scars
- Bud position relative to scar
- the winter bud has a leaf scar partially or completely surrounding it
- Bud scale number
- there is one scale on the winter bud, and it covers the scale like a cap
- 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
- Terminal bud
- there is no terminal bud on the branch
- Winter bud distribution
- the winter buds are distributed fairly evenly along the twig
- 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 conical (cone-shaped)
- the winter buds are ovoid (egg-shaped)
- Winter bud stalks
- the winter buds have no stalks
-
Flowers
- Enlarged sterile flowers
- there are no enlarged sterile flowers on the plant
- Flower appearance
- the flowers appear at the same time as the leaves
- Flower petal color
- NA
- 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 hairs
- there are hairs on some part of the inflorescence
- Inflorescence type
-
- the flowers grow out of the axil (point where a branch or leaf is attached to the main stem)
- the inflorescence has only one flower on it
- Number of pistils
-
- 3
- 4
- 5
- 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
- NA
- Petal fusion
- NA
- 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 fused to each other (not other flower parts), at least near their bases
- Stamen number
-
- 3
- 4
- 5
- 6
- 7
- 8
- Stamen position relative to petals
- the stamens are lined up with the sepals (antesepalous)
- Stamens fused
- the stamens are not fused to one another
-
Fruits or seeds
- Berry color
- NA
- Fruit tissue origin
- there are no flower parts that form part of the fruit
- Fruit type (general)
- the fruit is dry but does not split open when ripe
- Fruit type (specific)
-
- the fruit is an achene (dry, usually 1-seeded, does not separate or split open at maturity)
- 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 tree
-
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 fuzzy or hairy
- 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 truncate (ends abruptly in a more or less straight line as though cut off)
- 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 lobes, or it has both teeth and lobes
- 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
- 50–200 mm
- Leaf blade scales
- there are no scales on the leaf blades
- Leaf blade shape
- 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 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
- 50–250 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 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 is one leaf per node along the stem
- Specific leaf type
- the leaves are simple (i.e., lobed or unlobed but not separated into leaflets
- Stipules
- the plant has stipules
-
Place
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Specific habitat
-
- river or stream floodplains
- shores of rivers or lakes
- 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 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
- Lenticels on twigs
- there are clearly lenticels on the twigs
- Short shoots
- there are 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
-
- brown
- gray
- orange
- 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)
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.
- Maine
- extirpated (S-rank: SX), potentially extirpated (code: PE)
- Massachusetts
- fairly widespread (S-rank: S4)
- New Hampshire
- uncommon (S-rank: S3), W (code: W)
From Flora Novae Angliae dichotomous key
2. Platanus occidentalis L. N│E
American sycamore. CT, MA, ME, NH, RI, VT. River shores, riparian forests, swamps. Records from northern counties in ME represent cultivated or escaped populations. It is only (and formerly) native to the southern portion of the state.
Native to North America?
Yes and no (some introduced)
Sometimes confused with
- Acer pseudoplatanus:
- leaves opposite and bark close, not exfoliating (vs. P. occidentalis, with leaves alternate and bark with exfoliating patches that create different colored regions on the stem).
- Platanus hybrida:
- carpellate inflorescences paired or rarely solitary or in trios and middle lobe of leaf blade as long as or longer than wide (vs. P. occidentalis, with carpellate inflorescences solitary or rarely paired and lobes of leaf blade shorter than wide).