Nasturtium officinale

Basic information
Scientific name	Nasturtium officinale	Click to magnify
Common names	Watercress
Higher taxon	Brassicaceae, Capparales, Magnoliopsida, Magnoliophyta
Natural range	Europe.
Habitat	Various waterfront. Rice field, ditch, lakeside, etc.

Invasion information
Range in Japan	Most of entire Japan
Origin	Unknown.
Date	1870-1871
Route	Deliberate: Cultivated by foreign people for food and medicine, and after escaped.
Impact	Potentially: Competition with native species. Parasite (insects) Native organism(s) affected: Water front plants.
Regulation in Japan	No action for prevention, mitigation, control, or eradication.
Introduced range in other countries	North and South America, Asia, Oceania

Reference

Notes

Hotta et al. (1989) Useful Plants of the World. Heibonsha, Tokyo (in Jpn)
Jpn Assoc Advanc Phyto-Regul & Inst Contr Agrochem, Minist Agr, China (2000) Chinese Colored Weed Illustrated Book. Zenkoku-Noson-Kyoiku-Kyokai, Tokyo (in Chn and Eng)
Ministry of the Environment, Japan. The Invasive Alien Species Act (Accessed on 2011-1-11) http://www.env.go.jp/en/nature/as.html (in Jpn)
Osada (1976) Colored Illustrations of Naturalized Plants of Japan. Hoikusha, Osaka (in Jpn)
etc.