Norway maple (Acer platanoides)
Either side of Memorial Walk, west of Old Main
Six of these venerable giants line Memorial Walkway, connecting Old Main to the Bird Sanctuary. They probably were planted in 1906; a photo of that date shows them as tiny saplings with a tenuous grip on life. However, by 1909 another photo shows them large enough to dwarf several students standing nearby. Now, in their prime, they are about 80 ft. tall and 2.5 ft. in diameter. Record Norway maples top 130 ft. in height and 6 ft. in diameter.
Acer platanoides grows wild across northern Europe. It was introduced into North America near the end of the 18th century, and has been planted widely since. Norway maple feels at home in many parts of the United States, so much so that it has naturalized and threatens to crowd out native plants. It also apparently yields distinct varieties with profligate ease; one source describes nearly two dozen cultivars. Several purple varieties are to be found on campus.
The species name platanoides refers to the superficial similarity of its leaf to that of trees of genus Platanus - sycamores in the United States, plane trees in England. Another maple, Acer pseudoplatanus - not certainly represented on campus - is called "sycamore" in England and sycamore maple in the United States. To confuse matters even more, it also is known as the Scottish plane tree.
For further discussion of the muddy nomenclature of sycamores and plane trees, see Plane tree 'Pyramidalis' in Old Main Meadow.
See Acer platanoides on Wikipedia.