Spiraea japonica
Environmental Weed (2024)
Common names
Japanese spiraea
Biostatus
Exotic
Category
Vascular
Structural class
Trees & Shrubs - Dicotyledons
Flower colours
Red/Pink
Detailed description
A semi-deciduous shrub growing to 1.5 m tall, forming small thickets. Erect stems which are finely striated, downy and red when young, and reddish brown and smooth on older stems. The leaves are spreading or slightly ascending. 4-10cm long and 1-3 cm wide, and are lance-shaped to narrow-elliptical with irregular shallow serrations. The network of veins show distinctly on the pale green underside. The flower heads are dense hairy and spreading with numerous small (c. 2mm diam.) rose red flowers in a multi-stemmed head. Flowering takes place Nov-Mar. Seeds are fine and numerous.
Habitat
Terrestrial.
Conservation status
Not applicable
Detailed taxonomy
Family
Rosaceae
Ecology
Flowering
November, December, January, February, March
Year naturalised
1975
Origin
Japan, China
Reason for introduction
Ornamental
Other information
Etymology
japonica: Of Japan
Environmental Weed (2024)
This plant is named in a list of 386 environmental weeds in New Zealand 2024 prepared by DOC. 759 candidate species were considered for inclusion on this new comprehensive list of environmental weeds in New Zealand. The species considered were drawn from published lists of weed species, lists of plants that must be reported or managed by law if observed, existing national and regional programmes and agreements for pest management, and species already managed by the Department of Conservation (DOC). Candidate species were then assessed to see if they were fully naturalised and whether they have more than minor impacts in natural ecosystems. Read the full report here.