Tree Talk by Ned Barnard
and Pauline Gray

With their elegant, bone white upper branches, sycamore trees along Forbidden Drive are easy to spot in winter.

Members of the genus Plantanus, sycamores are plane trees native to North America. There are other plane trees in Chestnut Hill, but they aren’t natives. You’ll see these trees if you walk along East Highland Avenue between Anderson and Germantown avenues. They look somewhat like sycamores. Their bark peels off in flakes just like sycamores, but they don’t have bone white underbark exposed on upper limbs.Instead their upper limbs are pale tan, gray, olive, or cream colored.

These East Highland sentinels are London planes, hybrid crosses between the oriental plane, common in Europe, and the American sycamore. London planes were first observed in England over 300 years ago. The story goes that John Tradescant, gardener to Charles I of England, planted a sycamore in his London garden with seeds brought home from a collecting trip to Virginia. Supposedly Tradescant’s sycamore eventually crossed with an oriental plane also in his garden.

Whether this tale is true or not, London planes were well established in England by the late 17th Century. Because they are hybrids, London planes have variable seeds that produce offspring with differing leaf shapes and bark coloration often a bit like army camouflage patterns. But London planes definitely do not have the bone white underbark that you see on the great sycamore on Germantown Avenue opposite Weaver’s Way.

Sycamores can get too large for use as street trees. They grow best along streams and rivers—places with plentiful ground water. London planes, on the other hand, are quintessential urban street trees, able to contend with restricted root space and air pollution, but they, too, can get inconveniently large.