Spiraea japonica is a small, deciduous shrub up to 6 ft. (1.8 m) tall that invades a variety of habitats throughout the eastern United States.
Foliage
The alternate leaves are oval to lance shaped, toothed along the margins and 1-3 in. (2.5-7.6 cm) long.
Flowers
In late spring white to pink flowers occur in clusters at the tips of branches.
Fruit
Fruits are capsules that are smooth and glabrous. Seeds are 0.09-0.1 in. (2.2-2.4 mm) long.
Ecological Threat
Spiraea japonica invades a variety of habitats including fields, forests, stream banks and many disturbed areas. Once established, it can form dense stands which displace native vegetation and close open areas. It is native to eastern Asia and was first introduced into the United States around 1879 as an ornamental.