Elodea nuttallii

Basic information
Scientific name	Elodea nuttallii	Click to magnify
Common names	Florida elodea, Nuttall’s waterweed, esthwaite waterweed
Higher taxon	Hydrocharitaceae, Alismatales, Liliopsida, Magnoliophyta
Natural range	NE North America.
Habitat	Lake or pond, stream, waterfront.

Invasion information
Range in Japan	Kanto District to western Japan.
Origin	Unknown.
Date	Imported as an experimental material for physiology in 1920s-1930s. Feral population was recorded in 1961 at Biwako Lake, Shiga Pref.
Route	Deliberate: As an experimental material for physiology.
Impact	Competition with native species. Prevention of water current. Native organism(s) affected: Native submerged plants (e.g., Hydrilla verticillata)
Regulation in Japan	Keeping of this species in Saga Pref. are controled by a prefectural ordinance. Import to Australia is prohibited.
Introduced range in other countries	Europe, East Asia.

Reference	Notes
Ecol Soc Jpn (ed) (2002) Handbook of Alien Species in Japan. Chijinshokan, Tokyo (in Jpn) Osada (1976) Colored Illustrations of Naturalized Plants of Japan. Hoikusha, Tokyo (in Jpn) Shimizu (ed) (2003) Naturalized Plants of Japan. Heibonsha, Tokyo (in Jpn) etc.	100 of the Japan’s Worst Invasive Alien Species. For eradication of this species, grass carp Ctenopharyngodon idella was introduced in 1980s in Kizaki Lake of Nagano Pref. As a result, ecosystem of this lake was seriously changed.