EPPO Alert List – Pseudosasa japonica (Poaceae)
Why
Pseudosasa japonica (Poaceae) is a species of bamboo commonly grown as a garden ornamental species in the EPPO region. It is increasingly recorded in natural and semi-natural environments in the EPPO region (for example in Belgium and the Netherlands). The species has a wide climatic suitability which may aid the spread of the species in the EPPO region in the future.
Photo: Kurt Stüber from Wikimedia commons
Geographical distribution
EPPO region: Belgium, France, Georgia, Italy, the Netherlands, Spain (Canary Islands), United Kingdom.
Asia: China, Japan, Korea (Republic of).
North America: USA (Alabama, California, Connecticut, Delaware, Florida, Maryland, New Jersey, New York, North Carolina, Pennsylvania, South Carolina, Tennessee).
South America: Brazil.
Oceania: New Zealand.
Morphology
Pseudosasa japonica is a perennial, leptomorph bamboo species, 3-5 m tall.
Culms: erect or nodding, 1–3(–5) m tall, up to 1.5 cm thick; internodes long, finely ridged, finely mottled, with light ring of wax below each node; nodes slightly raised; sheath scar large.
Branches: usually 1 per node, without basal buds or branches on that branch, sometimes rebranching from distal branch nodes. Culm sheaths persistent, to 25 cm, basally glabrous, distally appressed hispid; auricles and oral setae absent; blade erect, 2–5 cm, abaxially glabrous.
Leaf sheaths: glabrous, margins membranous, not ciliate, auricles absent or small, erect; oral setae scarce, erect, or lacking; ligule oblique, long, slightly pubescent, eroded; abaxial ligule glabrous to finely ciliate.
Leaf blade: labaxially light green to glaucous, adaxially dark green, 15–37 × 1.5–5 cm, glabrous.
Inflorescence: panicle, open, obovate, 10-20 cm long.
Spikelets: curving, narrowly terete, 3.5–10 cm; florets 5–20(–25). Lemma 1.2–1.5 cm, glabrous.
Biology and Ecology
Pseudosasa japonica mainly reproduces vegetatively reproduction. Running rhizomes can act to facilitate the spread of the species. It prefers moist, fertile, well drained soils and it can tolerate full shade and a broad climatic suitability. If the species flowers, seed may be spread by wind.
Habitats
Ruderal habitats, roadsides, riverbanks, urban habitats (gardens), woodland.
Pathways for movement
The main pathway for movement into and within the EPPO region is via the horticultural trade. The species is a popular garden plant which is also grown in amenity areas.
Impacts
Pseudosasa japonica can form dense thickets which have the potential to outcompete native plant species. The dense structure may also impede access. In the USA (Pennsylvania, Maryland and West Virginia), the species is considered invasive. In the EPPO region, the species has been recorded growing in natural and semi-natural habitats.
Control
Pseudosasa japonica can be controlled by manual control ensuring that the rhizomes are removed. However, this is often very difficult due to the habitats where the species grows. Physical barriers may help to control unwanted spread. Chemical control options may be applied to above ground foliage and/or cut stems.
Sources
Flora of China (2020) Pseudosasa japonica (Siebold & Zuccarini ex Steudel) Makino ex Nakai, Available at: http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200026099
Lieurance D, Cooper A, Young AL, Gordon DR, Flory SL (2018) Running bamboo species pose a greater invasion risk than clumping bamboo species in the continental United States. Journal of Nature Conservation 43, 39-45.