| Invasion information | ||
| Range in Japan | Central to western Japan |
|
| Origin | Unknown. | |
| Date | Imported in Meiji era (1912 or earlier) | |
| Route | Deliberate: For horticulture | |
| Impact | Competition, hybridization with native species. | |
| Regulation in Japan | No action for prevention, mitigation, control, or eradication. | |
| Introduced range in other countries | Unknown. | |
| Reference | Notes |
|