. . . Or is it the London Plane tree? These two half siblings are difficult to tell apart, even by horticulturists.
The Sycamore is one of the largest native trees of the Eastern US, and is particularly conspicuous in winter when the mottled trunk holds its ghostly white branches in relief against a blue sky. Traditionally known in this area as the Buttonwood, it was collected in the wild and planted extensively as a street and landscape tree throughout our region. The distinctive tree functioned as a primitive billboard, as its presence in the distance signified the location of a hotel or public building.
Sycamores have a predisposition towards becoming almost entirely hollow as they age. These living tree tubes can survive for many years, and sections of hollow Sycamore were used for barrels, grain silos, smokehouses, and even temporary housing, the 18th century version of a pop-up tent.
The London Planetree is a mule- the offspring of two different species. In this case the parents are the Sycamore and the Oriental Planetree. Slightly smaller than its parental giant, it has almost replaced it in the modern landscape. The London Planetree is resistant to certain defoliating diseases that plague the Sycamore. It is also very tolerant of pollution, (which is why it was so widely planted in London during the Industrial Revolution.) Pollutants and dirt that adhere to the tree’s exterior flake away as the new bark emerges.
The bark is the most ornamental feature of these trees, and in winter a double line of Sycamores or London Planetrees arching high above street level is an iconic Philadelphia sight, from the streets of Old City to Chestnut Hill and beyond.