Rose family (Rosaceae)
Description: This introduced tree is 20-50' tall with multiple ascending branches; the crown is usually longer than it is wide. The gray bark of the central trunk has shallow furrows and flat scaly ridges; it is often partially covered with lichens. The bark of smaller branches and twigs is greyish or reddish brown and smooth with small lenticels. The terminal buds of the twigs are rather large (about ½" long) and usually pubescent; sometimes thorny spur shoots are present. The blades of the alternate leaves are 2-3" long and about half as much across; they are ovate with margins that are finely serrate or crenate. The upper surfaces of the blades are dark green, hairless, and shiny; their lower surfaces are pale green and dull. The petioles of the leaves are 1-2" long, light green, and slender.
During the mid-spring, clusters of several white flowers develop from the axils of young leaves; these flowers often appear shortly before the leaves develop. The pedicels of the flowers are slender and ascending to slightly drooping. Each flowers is ½–¾" across, consisting of 5 white petals, a light green calyx with 5 teeth, 15-20 stamens, and 2-3 styles. Each fertilized flower produces a single globoid fruit (a pome) about 1/3–1/2" across. The exterior of a mature fruit is light brown with pale dots, while its fleshy interior contains about 2 seeds. Usually, the flavor of the fruit is bitter. On mature fruit, the teeth of the calyx are usually deciduous. Fall color of the leaves is variable as this depends on the cultivar.
Cultivation: This small tree adapts to full or partial sun, moist to dry-mesic conditions, and soil containing loam, clay-loam, or sand. The pH of the soil can be acid to alkaline. Winter cold is tolerated to Zone 5. The Callery Pear is fast-growing, but rather short-lived (30-50 years); its branches are prone to ice and storm damage.
Range & Habitat: So far, the Callery Pear has naturalized in DuPage and Champaign counties in Illinois (see Distribution Map). It seems likely that this species will continue to spread in the state; some ecologists think it is potentially invasive, as the wild trees produce abundant fruits with fertile seeds. So far, this tree has been found in various disturbed habitats, including degraded open woodlands, woodland borders, thickets, fence rows, and fallow fields. This habitat information has been compiled from several states in the eastern half of the United States, where the Callery Pear has naturalized. This tree is widely cultivated as an ornamental landscape plant and about 20 cultivars are available. While some cultivars are self-sterile, cross-pollination across cultivars can produce trees with fertile fruit. The Callery Pear is native to East Asia.
Faunal Associations: The fruit is eaten by songbirds, including the Robin, Starling, Cardinal, and Northern Mockingbird. These birds distribute the seeds to new locations.
Photographic Location: A thicket at Lake-of-the-Woods in Champaign County, Illinois. The photographed tree is a naturalized specimen of the Callery Pear.
Comments: While the Callery Pear is an attractive landscape tree, it may eventually become as much of a pest as Morus alba (White Mulberry) and Elaeagnus umbellata (Autumn Olive). Another common name of Pyrus calleryana is 'Bradford Pear,' which refers to a widely planted cultivar of this species. Because an old cultivar of the Table Pear, Pyrus communis, is also called 'Bradford Pear,' this common name is potentially misleading. The Table Pear, which is cultivated for its edible fruit, is similar in appearance to the Callery Pear. However, both its flowers and pear-shaped fruit are larger in size.