Invasion information |
Range in Japan |
Almost entire Japan (no record in Aomori, Iwate, Akita, and Fukushima Prefs.) |
|
Origin |
Germany |
Date |
German people introduced in ca. 1920. The first establishment was in a pond of Suma, Hyogo Pref. |
Route |
Deliberate: As ornamental plant. |
Impact |
Actually: Competition with native species. Disturbance of water flow. Native organism(s) affected: Native aquatic plants. |
Regulation in Japan |
Import, transport and keeping are prohibited in Japan by the Invasive Alien Species Act. Import to Australia is prohibited. |
Introduced range in other countries |
North America, S Europe, N Africa, Asia, Oceania, etc. |