| Invasion information |
| Range in Japan |
Kanto District and western region in main land of Japan, Okinawa, and Ogasawara (Bonin) Islands. |
|
| Origin |
Unknown |
| Date |
The first record in Japan was in 1959, at Mie Pref. The first record in Kanagawa Pref. was in 1980. Spread since late 1990s. |
| Route |
Unknown |
| Impact |
Potentially: Competition with native plants. In foreign countires, noxious weed in crop field of rice and soy beans. Disturbance of canals. Native organism(s) affected: Native swamp plants, crops, etc. |
| Regulation in Japan |
No regulation in Japan. |
| Introduced range in other countries |
Tropical to warm-temperate zone in Asia, Australia, Europe, and North and South America. |