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Paspalum distichum

Basic information
Scientific name Paspalum distichum

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Common names Knotgrass, Jointgrass, Water couch, Seashore paspalum
Higher taxon Poaceae, Poales, Liliopsida, Magnoliophyta
Natural range North America.
Habitat Natural beach, lake or pond, rice field, sandy place, swamp, waterfront.
Invasion information
Range in Japan Kanto and Hokuriku District to western Japan Range in Japan
Date The first record was in 1924 in Wakayama Pref. Spread since 1945. A variety P. d. var. indutum was at first recorded in 1970 in Fukuoka Pref., and have spread.
Route Deliberate: for animal feeding stuff
Accidental: unknown vector
Impact Competition with native and crop plants. Host of insects, fungi, and viruses.
Affected organism: Native and crop plants (including rice).
Regulation in Japan South Korea prohibits import of this species.
Introduced range in other countries South America, Europe, Oceania, Asia, Africa
Reference Notes
  • Jpn Assoc Advanc Phyto-Regul & Inst Contr Agrochem, Minist Agr, China (2000) Chinese Colored Weed Illustrated Book. Zenkoku-Noson-Kyoiku-Kyokai, Tokyo
  • Shimizu (ed) (2003) Naturalized Plants of Japan. Heibonsha, Tokyo (in Jpn)