ARBORETUM JOURNAL

London Plane Tree Platarus x acerifolia
It looks like a sycamore, but it’s a plane!

As you near the front steps of Kendall Hall, you see to your left a magnificent tree with shaggy bark and the arboretum number 7 high on its trunk. This is a London plane that dates back to the late 1800s, soon after the founding of Chico Normal School in 1887. In fact, it is an excellent candidate for being our “Founders Tree” if we so choose.

A 1902 photo of the old administration building, which burned in 1927, shows many London planes, interspersed with California incense cedars, just to the west. Several of these still stand between Kendall and Trinity and presumably were planted about the same time.

The “x” in its scientific name indicates that this is a garden hybrid and did not come out of the wild. As nearly as botanists can determine, two sycamore species, Platanus occicentalis and P. orientalis, were planted in a Paris botanical garden about 1700. Orientalis is the European sycamore (or “plane”), while occidentalis comes from the U.S. East Coast. They hybridized (the pollen is wind borne), and some of the resulting seeds were sent to London where the new hybrid came up. It proved to be a popular and hardy tree for England and soon gained favor all over the world. Market Street in San Francisco is lined with these as well as streets in Shanghai and London. It has excellent resistance to urban smog and other mistreatment.

On campus, west of the BMU, there are two magnificent East Coast planes (P. occidentalis #93). Their chalk-white trunks, large pairs of woody fruit balls, and leaves like London plane set them apart from our native California sycamores (Platanus racemosa #45) along the creek. The latter have deeply lobed leaves, gray and greenish shaggy trunks, and strings of 5 to 7 small fruit balls. They are very susceptible to the anthanose fungus disease and may drop several successive crops of diseased leaves and small branches during cold, wet springs. The new leaves also shed masses of irritating sharp hairs as they expand. Hardly a tree for the small yard!

Wes Dempsey