NATIVE RANGE: Eastern Asia

PATHWAYS: horticulture

POSSIBLE TO DETECT: year-round

FLOWERING SEASON: May – June

DESCRIPTION: A deciduous shrub with multiple upright stems. Twigs brown to reddish-brown, sometimes with fine hairs. Leaves are alternate, simple and narrow-lanceolate. Leaf-margins are toothed near the apex but entire towards the base. Leaves are green above, paler below, in some cultivars yellowish or reddish. Flowers are small, usually pink, flat-topped terminal clusters, with a diameter of at least 5 cm. Highly variable due to many cultivated varieties.

HABITAT: Forests, forest clearings, ruderal habitats and a variety of wetlands, including riparian forests.

STATUS: Widespread; most observations from Sweden and the United Kingdom. Also widely planted and one of the most common shrubs in urban green areas. In Slovenia it is invasive in the lower part of the Vipava valley (Panovec, Stara Gora), in parts of Pohorje, and in the surroundings of Ljubljana. Locally it is entirely replacing the natural scrubs in the undergrowth of forests. 

SIMILAR SPECIES: Other Spiraea-species have erect clusters of flowers. They can also be distinguished by the shape of leaves, leaf margins and hairiness (see details on the facing page). Some hybrids may have intermediate characteristics. From a distance, hemp agrimony (Eupatoria cannabina) may appear similar, but has palmately compound, opposite leaves.

SOURCE: Field Guide to Invasive Alien Species in European Forests