The Callery Pear (Pyrus calleryana) is a species of pear native to China. The leaves are oval, 4-7 cm long, glossy dark green above, slightly paler below. The flowers are produced in early spring before the leaves expand fully, and are white, with five petals, and about 2-3 cm diameter. The fruit is about 2 cm diameter, hard, almost woody until softened by frost, after which it is readily taken by birds, which disperse the seeds in their droppings. In summer, the foliage is dark green and very smooth, and in autumn the leaves consistently turn brilliant colors, everything from yellow and orange to more common red, pink, purple, and bronze. Sometimes, several of these colors my be present on an individual leaf, and often the tree will turn from the outer top to the inner bottom, like a maple.

Cultivation

It is widely planted throughout North America as an ornamental tree. The natural symmetry of several cultivars lends to their use in somewhat formal settings, such as office parks or industrial parks. It is commonly planted for its decorative value, but its hard little fruits are taken by birds. Its beautiful white blossoms can be seen in early spring along the boulevards of many Eastern US towns. Unfortunately, when in flower, the Callery Pear produces a sickly-sweet smell that some have likened to decaying crab meat, or jasmine and dog vomit.

The Callery Pear is proving to be an invasive species in some areas of North America, pushing out native American plants and trees. Self-sown plants often differ from the selected cultivars in less regular shape, and also in frequently being densely thorny.

There are several cultivars in commerce:

• 'Aristocrat'
• 'Autumn Blaze'
• 'Bradford' (Bradford Pear, the most commonly planted cultivar)
• 'Capital'
• 'Cleveland Select'
• 'Fauriei'
• 'Redspire'
• 'Whitehouse'

Bradford pear in flower, Hemingway, South Carolina

The neat dense upward growth of 'Bradford', which makes it desirable in cramped urban spaces, also results in a multitude of narrow weak crotches unless corrected by selective pruning at an early stage. These weak crotches make the Bradford Pear susceptible to winter damage where snowfall is heavy or when ice storms occur, or during the high winds of severe thunderstorms. Because of this, and the relatively short lifespan that results, many groups have discouraged their use in landscaping in favor of other stronger trees including other Callery Pear cultivars like 'Cleveland Select', but also more locally native tree species.

External links

• Plant Invaders of Mid-Atlantic Natural Areas (http://www.nps.gov/plants/alien/pubs/midatlantic/pyca.htm)