Rumex obtusifolius

Basic information
Scientific name	Rumex obtusifolius	Click to magnify
Common names	Broadleaf dock, Bitter dock
Higher taxon	Polygonaceae, Polygonales, Magnoliopsida, Magnoliophyta
Natural range	Europe.
Habitat	Various grassland, farm area, roadside, riverside, vacancy, etc.

Invasion information
Range in Japan	Most of entire Japan
Origin	Unknown.
Date	The first record was in 1909 at Hokkaido. This species is postulated to be introduced in late 19C.
Route	Accidental: Details unknown
Impact	Potentially: Competition with native species, crops, etc. Native organism(s) affected: Native plants, feed crops, fruit trees, etc.
Regulation in Japan	No action for prevention, mitigation, control, or eradication.
Introduced range in other countries	Asia, N Africa, Oceania, N and S America.

Reference	Notes
Osada (1976) Colored Illustrations of Naturalized Plants of Japan. Hoikusha, Osaka (in Jpn) Shimizu (2003) Naturalized Plants of Japan. Heibonsha, Tokyo (in Jpn) etc.	A native beetle Gastrophysa atrocyanea specifically feed on this plants. Plants of the genus Rumex frequently hybridize each other and have hybrid vigor.