The Ulmus parvifolia, most commonly known as the Chinese elm, is a hardy tree with a slender trunk, vase-shaped profile and distinctive exfoliating bark that gives it a mottled, multicolored appearance. This variety of elm is native to China, Korea, Vietnam and Japan and has been cultivated around the world, first appearing in Europe during the 18th century. Its small, serrated leaves, which spread into a broad canopy of gently pendulous branches, can remain evergreen in warmer climates, but it is deciduous in most regions. Even in colder climates, though, the leaves of the Ulmus parvifolia can remain on the tree from when they first bud in March to as late as December or January. In these cooler regions, foliage colors change in late autumn, shifting from their usual dark green to a varied palette, including shades of purple, yellow and red.
Able to thrive in most soils, the Ulmus parvifolia is a sturdy, fast growing tree that requires little care and maintenance, usually involving nothing more than attaching a new sapling to a stake in order to encourage it to grow straight. The tree grows well in urban and suburban environments and can thrive in areas where air pollution, drought and poor drainage are present. It is more resistant to Dutch elm disease than other elm species are, and in some regions, it is replacing the native elms that have fallen to the disease. Ulmus parvifolia is able to grow to heights of 80 feet (24.4 m) tall, but mature trees more typically range from 40 to 50 feet (12.2 to 15.2 meters). These features have made the tree a popular choice for landscaping along residential streets, courtyards and plazas and on parking lot islands.
Most species of elm trees will flower and produce seeds in the spring, but the Ulmus parvifolia doesn't bear fruit until late autumn. This fruit, called a samara, has a papery wing extending from the fruit and resembles a helicopter blade. The shape of the samara allows it to be carried easily by the wind, allowing the seed to grow away from the parent tree.
In some regions of the world, the Ulmus parvifolia has become too effective at spreading its seeds. For instance, in South Africa, the tree has become invasive and is having a detrimental effect on the indigenous plant life. This invasive tendency has been noted in portions of North America and Australia as well, though not to the same degree.
