Callery pear has become an invasive tree species.
By Rick Knight, Zoo Horticulturist
Topeka Zoo and Conservation Center
Pyrus calleryana, Callery pear, is native to China and Vietnam, and was introduced into the United States in the early 1900s by the Arnold Arboretum of Harvard University. It is an ornamental, deciduous, medium-sized tree with white flowers and good fall foliage. It has a small fruit that is eaten by birds, which disperse the seeds. The various cultivars are generally thought to be self-incompatible, unable to produce fertile seed when self-pollinated. But they are fertile when cross-pollinated with other cultivars. Callery pear seedlings are now taking over old fields along roadsides and wasteland and are a new weed species. They now are on many states’ list of invasive species and are headed west.
