Range and Habitat
Sycamore (Platanus occidentalis) is found in southern Maine in cultivation, but is thought to be extinct in the wild there, or at best quite rare. It ranges west across southern New Hampshire and Vermont to southern Wisconsin and into Iowa, thence south throughout the eastern United States to the Gulf Coast. Small disjunct populations occur in northeastern Mexico. Sycamore will sometimes grow on upland sites, but it prefers deep, rich valley soils, sharing habitat with other bottomland trees. It is a pioneer species on river floodplains, tolerating periodic flooding, but not continuously saturated sites.
Description
Sycamore is a rapidly growing tree that can live to be over 250 years old. It is the largest deciduous hardwood in eastern North America, with a thick trunk, many stout, spreading branches, and a strong lateral root system. Mature trees reach heights of 35 meters, with bole diameters of two meters or more. Specimens in the virgin forest of the Midwest were enormous. Andre Michaux (1746 – 1802), an 18th century French botanist and explorer, reported a Sycamore growing on an island in the Ohio River that was 40 feet in circumference and 13 feet in diameter! Very few trees of that size are left, but large trees still exist in river valleys throughout its range. The largest in New England is the Pinchot Sycamore, on the banks of the Farmington River in Connecticut.
The distinctive mottled bark of Sycamore. This specimen is 105 years old, middle-aged for a Sycamore.
Other than great size, the outstanding characteristic of Sycamore is the bark – being various shades of gray-brown and flaking off in patches, revealing under-bark that is chalky white to yellow to tan, giving the trunk and major branches a uniquely mottled appearance. The leaves are large, broad, and maple-like, with sharp pointed lobes. The tiny, dry fruits are called achenes, held in aggregate on long-stalked spherical balls. These persist on the tree over the winter, breaking up the following spring, and releasing the fluffy seeds on the wind, much like Cottonwood. The seedlings grow best on open, damp sites with plenty of sun, they are intolerant of shade.
Wildlife Value
Sycamore provides food and habitat to numerous species of animals. Finches and other small birds feed on the seed heads and forage for insects within the spreading canopy. Older Sycamores almost always become hollow as the heartwood decays. Cavity dwelling mammals that move in include Black Bears, Raccoons, and Opossums. Indeed, in pioneer times, a horse or cow was often stabled in a large, hollow Sycamore, and sometimes a whole family took shelter while the log cabin was being built! Cavity nesting birds include Owls, Woodpeckers, and Wood Ducks. In modern times Chimney Swifts nest in chimneys, but in the primeval forest entire colonies nested in giant Sycamores, as described in the following excerpt penned by 19th century naturalist and artist John James Audubon (Swifts were called “Swallows” by early ornithologists):
The sun was going down behind the Silver Hills, the evening was beautiful; thousands of Swallows were flying closely above me, and three or four at a time were pitching into the hole, like bees hurrying into their hive. I remained, my head leaning on the tree, listening to the noise made within by the birds as they settled and arranged themselves, until it was quite dark.
Uses
Sycamore makes a fine shade tree, especially in large parks and along the shores of rivers and lakes where it has room to spread. It was formerly planted as a street tree, and large specimens are still seen in cities and towns, but the roots can damage streets and sidewalks, so it has fallen from favor for that purpose. The wood is of medium density, hard and tough. It is not resistant to decay, nor is it suitable for construction, but it is used for pulpwood, particle board, crates, and boxes; and it makes an excellent butcher block because it is almost impossible to split.
References
Peattie, Donald Culross. 1950. A Natural History of Trees of Eastern and Central North America. Houghton Mifflin, Boston.
Sullivan, Janet. 1994. Platanus occidentalis. In: Fire Effects Information System [online]. United States Department of Agriculture. United States Forest Service.