The Bradford cultivar is without thorns, however, plants that have Bark Callery pear trees have scaly gray-brown bark and branches with numerous short lateral twigs. Many cultivars exist with slightly different characteristics; all contribute to the species' invasiveness. Callery pear is a small to medium-sized tree with a compact, symmetrical, pyramidal or columnar shape that spreads to become oval with age. Alternate, simple, oval leaves grow to 3 inches long and 2 inches wide. The bark is typically light gray. Callery Pear grows to 40 feet (12.2 m). Callery Pear: History, Identification, and Control ... inches in diameter is a basal bark treatment (figure 6) in which a triclopyr ester product (Pathfinder II) is sprayed over the lower 12 to 15 inches of each trunk. Callery Pear Pyrus calleryana Rose family (Rosaceae) Description: This small to medium-sized tree is 20-50' tall with multiple ascending branches; the crown is usually longer than it is wide. The various cultivars of this species are more commonly available than the species itself. The gray bark of the central trunk has shallow furrows and flat scaly ridges; it is often partially covered with lichens. Callery pear grows pyramidal to columnar in youth; with age it broadens and reaches heights of 30–50 feet. ... Bark is gray-brown, smooth on young trees, splitting into scales with age. Review of risks should be undertaken before selecting this tree for planting sites. Callery pear has invasive traits that enable it to spread aggressively. Be sure to get good coverage of the entire stem but This tree is under observation and may be listed on official invasive species lists in the near future. Twigs Twigs are reddish-brown to gray and stout, with relatively large, fuzzy, light tan-gray terminal buds on the spur shoots and branch tips.