Invasion information |
Range in Japan |
Kanto and Hokuriku District to western Japan. Ogasawara (Bonin) Islands. |
|
Origin |
Unknown. |
Date |
First introduction was in 1920s in Okinawa and Ogasawara. Infested on mainland since 1990s. |
Route |
Deliberate: as ornamental plant. In past, many water Water lettuces were imported and cultivated, and distributed in Japan. |
Impact |
Competition with native plants and rice. Water pollution. Inhibition of water current. Allolopathy. Host for insects, land snails, and fungi. Native organism(s) affected: Native aquatic plants and rice. |
Regulation in Japan |
Import, transport and keeping are prohibited in Japan by the Invasive Alien Species Act. |
Introduced range in other countries |
Asia, Australia, North and Latin America |