A Likely Pyrus ×Calleryana × Communis (Rosaceae) Hybrid Found in Connecticut

Abstract

Pyrus 3calleryana Decne., or Callery pear, is a native of China and Korea that has been widely planted as an ornamental street tree in the eastern United States (Dirr 2009). It has become widely established as a wild species in North America, now ranging from New Hampshire to Texas, and several states consider the Callery pear an invasive plant (Natural Resources Conservation Service 2020). In New England, it has been documented in Massachusetts, Connecticut, and New Hampshire (Haines 2011). We observed in Connecticut that P. 3calleryana appeared to be more common than reported and conducted a survey to assess the species’ true range in New England. While conducting these surveys near the Buckland Hills Mall in Manchester, Connecticut, we noticed a Callery pear-like tree with large fruits. The tree was growing in an unmowed thicket with several other weedy species. Wild individuals of Callery pear are frequent around the mall and along Interstate 84 a short distance away. The large-fruited tree was approximately 3 m tall with a stem about 10 cm in diameter. The tree was quite prolific, bearing hundreds of round fruits 4–6 cm in diameter, much larger than the typical 1 cm fruits of Callery pear. Common pear, Pyrus communis L., the other species that can typically be found in Connecticut (Dreyer et al. 2013), does not have round fruits. The combination of the large size and round shape led to the conclusion that the tree was probably a hybrid of P.3calleryana and P. communis. The fruits of the likely hybrid tree were bitter and astringent and had numerous sclereids, giving the flesh a very gritty texture, traits that confirmed the Callery pear parentage. Catling and Mitrow (2014) reported that several larger-fruited specimens that appear close to P. 3calleryana are known throughout the North American range of the species and hypothesized that these individuals may be hybrids involving P. bretschneideri Rehder or P. communis. While P. communis