The American hornbeam is nicknamed "ironwood" because of the strength of its wood. It is also referred to as "musclewood" because of the trunk's resemblance to muscles. American hornbeams and European hornbeams were both planted early on in the Park's creation. The older, larger hornbeams tend to be European, while only American hornbeams are now planted in Central Park. Distinguishing between the two can be difficult and involves comparing bud sizes and fruit bracts, though the task becomes easier once fall arrives; the American hornbeam's wonderful, striking yellow-orange foliage differentiates it from the European hornbeam.