American Sycamore – Fortress of the Stream Bank
One of eastern North America’s greatest native trees is the American Sycamore, Platanus occidentals. Perhaps the most endearing feature of this legendary tree is its bark, especially in winter when the white bark, mottled with green and brown is fully exposed.
These trees often exceed a hundred feet in height and stand guard along streams like the bones of giant wizards, protecting the stream banks from erosion and providing many ecosystem services.
One of the Most Important Riparian Trees in North America
They are one of the most important riparian trees because they readily colonize deforested areas since their seeds are spread by wind and water. They are fast growing and cuttings will easily take root. I have seen poles cut from living sycamore branches and young trunks inserted into pre-dug holes take root and prosper.
According to the late Donald Peattie, botanist, “The Sycamore is, in girth of trunk, the largest deciduous hardwood of North America” (1). Francois Michaux, in 1802 measured a sycamore on the banks of the Ohio River “at four feet beyond the surface of the soil, and found it forty-seven feet in circumference” (2). “So it was that pioneers often stabled a horse, cow or hog in a hollow Sycamore, and sometimes a whole family took shelter in such a hospitable giant” (3).
The fruiting structures of the Sycamore are often called “button balls” because they are round and about one inch in diameter. When the seed balls mature they split apart revealing their nutlets with downy awns much like dandelion seeds. Wind and water can rapidly disperse these seeds to become new guardians along streams.
The wood is hard and difficult to split. Pioneers used cut-out portions of the trunk as solid wheels and Native Americans used the hollowed out trunks for canoes. Today the wood is used to make butcher blocks because of its unwillingness to split.
But trees provide much more than wood! They provide shade that cools the water from its adjoining stream. Leaves feed aquatic insects such as cranefly larvae (4). Roots hold the soil on the banks of the stream and uptake nutrients. The leaves have stomata which sequester carbon, the seeds are food for wildlife. Trees provide cover for all sorts of critters and beauty for us to admire. These “ecosystem services” are vital to the improvement of both air and water quality. That’s why there is so much emphasis on planting trees beside streams. Forested lands adjacent to water are called riparian forest buffers and there are many programs to assist with installing them.
American Sycamore is one of our best native trees to carry out all these ecosystem services. To find out how you can help restore our streams and bays contact your local USDA office, Soil and Water Conservation District office, the Chesapeake Bay Foundation or send me an email, I’ll be glad to help you.
(1).Peattie, Donald C., 1966, A Natural History of Trees of Eastern and Central North America, Houghton Mifflin, Boston MA, pg. 318.
(2). ibid., pg. 319
(4). Sweeney, B. W. 1993. Effects of streamside vegetation on macroinvertebrate communities of White Clay Creek in Eastern North America. Proceedings of The Academy of Natural Sciences of Philadelphia 144:291-340. Request PDF.
© Robert N. Whitescarver