London Plane Tree – Platanus x acerifolia
Bayne Park’s London Plane tree can be found at the edge of the parking lot near the gazebo with long limbs outstretching towards Bayne Library. It is easily recognizable during any season due to the exfoliating bark which makes its trunk and branches look as if they are covered in military camouflage.
The London Plane tree is a hybrid between two tree species, the American Sycamore and the Oriental Plane tree. Exactly how this combination of species from widely divergent parts of the globe occurred is lost to time, but we do know that the London Plane trees were praised for their ability to tolerate the nastiest smog and grime of London during the Industrial Revolution, and thus they became a hardy option for city and park trees.
The London Plane tree is so similar in appearance to its American parent the Sycamore, its identity is frequently mistaken.
The flaking bark peels away in sections or sheets, leaving a dappled trunk. This occurs because the bark lacks elasticity.
Pealing bark helps to clears away pollution that would otherwise block gas exchange through the lenticels, which are small pores through the protective outer bark that allow gas exchange between the living tissue of the inner bark and the surrounding air.
In addition to helping the tree eliminate harmful insects and parasites, the exfoliating bark also discourages vines from overtaking the tree.
New leaves in spring are tomentose (covered in a white layer of matted wooly down) which can persist on the bottom surface of the leaf, with the top of the leaf developing and otter-like sleekness as it ages. The sleekness limits the attachment of dirt and grime onto the leaf surface and allows rain to easily rinse away anything that does attach. This optimizes photosynthesis and the health of the tree.
Female flowers give way to fuzzy spherical fruiting balls, about the size of a ping pong ball, which typically hangs in pairs from long pendulous stalks. They ripen to brown in October and can last into winter. Each fruiting ball consists of numerous, densely-packed, tiny seed-like fruits called achenes. As time progresses, the fruiting balls disintegrate as wind disperses their seeds, often in downy tufts. The seeds provide food for wildlife such as Carolina Chickadees, American Goldfinches, Purple Finches, Mallard Ducks, Beavers, Muskrats and Squirrels.
The leaves of the London Plane tree turn a beautiful yellow hue in the autumn. When the leaves fall look at the base of the petioles, the stalk that joins a leaf to a stem, to see the cup-shaped end which concealed the bud. As the bud increased in size it forced the leaf to fall.
The London Plane tree is valued greatly for its shade and majestic stature, while the wood creates highly sought after lacewood when quarter-sawn. The lacy pattern is due to its cellular structures of medullary rays that reveal dark reddish-brown flecks against a lighter background. Lacewood is used in many fine woodworking projects such as carving, turning, inlays, furniture, and even architectural elements.
Sprout Lands: Tending the Endless Gift of Trees by Arborist William Bryant Logan, who trained forty London Plane trees in the central plaza in front of the Metropolitan Museum of Art using a historic pruning technique known as pollarding. The technique allows maximum sun penetration in the winter to warm the plaza and maximum shade in the summer for cooling, and also limits the height of the trees to maintain the view of the building facade.
Thank you for joining us and virtually meeting our London Plane tree at Bayne Park today. We hope this virtual experience helps you to feel connected to the trees and we encourage you to visit the trees in person once Bayne Park reopens.
Check back every Treesday Tuesday for the next virtual installment of Meet a Tree from Bayne Park!