American sycamore

Platanus occidentalis
Family: Platanaceae

Natural HistoryAmerican sycamore
Leaves and fruit of American sycamore
Photo credit: Larry Korhnak, University of Florida

Sycamore, also known as American planetree, buttonball tree, or buttonwood, is a common shade tree throughout much of the eastern United States. It is one of the largest broadleaf tree species in North America. Its distinctive fruits, flaking bark, and large, lobed leaves make it easy to spot. The roots of the trees intertwine and help to stabilize soils, so sycamores are often grown to minimize erosion, especially along stream banks. They are useful in reclamation sites, due to the trees' tolerance to saturated soils, or acidic conditions. In Florida, sycamores have been planted over phosphate mining sites. The trees are susceptible to damage from high winds, ice, pollutants in the air, and a variety of insects and diseases and may also suffer from scorched bark in fire-prone areas.

Habitat & Range

Sycamore is found from southern Ontario, south into Florida and west as far as Michigan, Nebraska, and Texas. The tree grows best on moist, rich soil margins of streams and lakes, or on rich bottomlands. It is commonly found in lowlands and old fields.

Wildlife Use

Although not a significant wildlife tree, some species benefit from sycamore trees, including songbirds like finches and juncos that eat the seeds. Beaver, squirrel, and muskrat also consume the fruits and white-tailed deer occasionally browse on the vegetation. Many cavity-nesting birds, such as owls, flycatchers, and chimney swifts, inhabit the nearly hollow trunks of older trees. Wood ducks are known to build nests in the old tree trunks and some species of bats use sycamores as nursery trees.

Human Use

The wood from sycamore is coarse-grained and slightly twisted, but not very strong. It is used to make boxes, crates, yokes, furniture, butcher's blocks, and woodenware. Baskets may also be fashioned from the bark or thin strips of wood. Some trees are grown for timber that may be used for interior trim work, veneer, or pulpwood. This fast-growing, long-lived species is frequently planted as an ornamental in backyards or along roadsides. It is also suitable for planting along watercourses where the interlacing roots minimize stream bank erosion. 


 

Identifying Characteristics

Size/Form: Sycamore is a large, massively spreading, deciduous tree that commonly grows to a height of 100' and rarely to heights of 150' to 170' and has an open, somewhat irregular crown. Diameter ranges from 3 to 14 feet.
Leaves: The leaves are simple, alternate, and deciduous. They range from 4-7 inches in diameter, and are broadly oval in shape, palmately 3-5 lobed, and with shallow sinuses. Leaves have a long, tapered apex. The leaf base is flat or heart-shaped. Leaf margins are wavy and dentate. The leaf surfaces are light green and glabrous above, with pubescence along the veins below. Leaf petioles are stout and hollow, 3-5 inches long, enclosing the lateral buds in their swollen bases.
Twigs: The twigs are slender, zigzagging, orange-brown, becoming gray. The pith is homogeneous.
Bark: The bark is thin and creamy white at first, but becomes brownish and mottled with deciduous, plate-like scales as the tree ages. These plates fall off to reveal whitish-green inner bark. The base of old trees appears furrowed and scaly.
Flowers: The flowers are unisexual and very small, appearing in dense, stalked heads.
Fruit: Individual fruits are needlelike achenes that taper to a sharp point and have many fine hairs to help with wind dispersal. The fruits are clustered into spherical heads about the size of ping-pong balls. Each head (or multiple fruit) is held out from the twig on a slender stalk 3-6 inches long. At maturity the achenes dry to a yellow-brown and the cluster falls apart, leaving only a small "wooden" core attached to the stalk.
Similar Trees on the Florida 4-H Forest Ecology Contest List:
  • Florida Maple has similar venation and a similar leaf shape but the leaf arrangement is opposite, rather than alternate.
  • Tuliptree also has broad, lobed leaves and the arrangement is alternate, but the shape is different and there are only 4 pointed tips coming off the leaf.

 

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