Sycamore - Not Just a Planetree

A Brief Sycamore Biography

Upwards view of a sycamore tree in autumn
(Janos Radler/Moment/Getty Images)

The sycamore tree (Platanus occidentalis) is readily identifiable with broad, maplelike leaves and a trunk and limb complexion of mixed green, tan and cream. Some suggest it looks like camouflage. It is a member of one of the planet's oldest clan of trees (Platanaceae) and paleobotanists have dated the family to be over 100 million years old. Living sycamore trees can reach ages of five hundred to six hundred years.

The American sycamore or western planetree is North America's largest native broadleaf tree and is often planted in yards and parks. It's hybridized cousin, the London planetree, adapts very well to urban living. The "improved" sycamore is New York City's tallest street tree and is the most common tree in Brooklyn, New York.

Champion

The record American sycamore, according to The Urban Tree Book and the Big Tree Register, is 129 feet tall. This Jeromesville, Ohio tree has a limb spread that spans 105 feet and the trunk measures 49 feet in circumference.

Threats

Unfortunately, sycamore is susceptible to anthracnose fungus which makes leaves turn brown and contorts stem growth. "Witches' brooms" or leafless sprout clusters form and grow along the limbs. Most urban plantings are of the hybrid London planetree because of its resistance to anthracnose.

Habitat and Lifestyle

The deciduous sycamore is fast growing and sun-loving, "growing seventy feet in seventeen years" on a good site. Very often it divides into two or more trunks near the ground and its massive branches form a wide-spreading, irregular crown. Mature trees usually develop hollow portions and areas of decay making them vulnerable to wind and ice.

The outer bark peels away to create a mottled patchwork of tans, whites, grays, greens and sometimes yellows. The inner bark is usually smooth. The leaves are very large with 3 to 5 leaf lobes and are often 7 to 8 inches long and wide.

Stalked unisexual flowers of both sexes appear on the same tree when leaves emerge. Fruits dangle from long stems and are aggregates of feathery seed nutlets (achenes). The tree is a very aggressive stump sprouter.

Lore

  • The tree was probably named by early colonists who noted a resemblance to the English sycamore maple (Acer pseudoplatanus). The sycamore tree of the Bible is actually the sycamore fig (Ficus sycomorus).
  • The tree is not very good for construction but is highly prized as butcher blocks.
  • A hybrid developed from the American sycamore, called the London planetree, has become the urban tree of choice in North America and Europe.
  • Sycamore seeds accompanied the lunar orbit of Apollo 14 in 1971 and were planted across from Philadelphia's Independence Hall.