EPPO Global Database

EPPO Reporting Service no. 09 - 2009 Num. article: 2009/186

Invasive aquatic plants in Japan


In Japan, alien aquatic plants have been introduced since the 1800s, for example Cabomba caroliniana, Egeria densa, Eichhornia crassipes, Iris pseudoacorus, Myriophyllum aquaticum, and M. brasiliense. In the past few decades, more and more alien aquatic plants have been newly introduced and commercially sold by various routes due to massive demand for aquarium and gardening. Amongst the more than 300 aquatic plants available on the market as aquarium plants, over 40 species are naturalized in Japan, and some of them have shown invasive behaviour. Thirty seven of these species are listed below with their families, origin and distribution in the EPPO region when available. Species are classified according to their status in Japan.

Alien species naturalized and widespread in Japan:
Species
Origin
Occurrence in EPPO region
Eichhornia crassipes (Pontederiaceae)
(EPPO A2 List)
S-Am.
ES, IL, IT, JO, PT
Egeria densa (Hydrocharitaceae)
(EPPO List of Invasive Alien Plants)
S-Am.
Widespread
Elodea nuttallii (Hydrocharitaceae)
(EPPO List of IAP)
N-Am.
Widespread
Iris pseudacorus (Iridaceae)
Eur., W Asia, N-Af.
Native, widespread
Paspalum distichum var. distichum,
P. distichum var. indutum (Poaceae)
Neotrop.
CY, ES (incl. Azores, Baleares, Canarias), FR (incl. Corse), GB, GR, IT (incl. Sardinia), PT (incl. Madeira), RO, TR
Landoltia punctata (Lemaneaceae)
SE Asia, Australia
ES, IL
Wolffia globosa (Lemnaceae)
Asia, N ; S Am.
/
Cabomba caroliniana (Cabombaceae)
EPPO List of IAP
Am.
BE, FR, GB, HU, NL
Nasturtium officinale (Brassicaceae)
Eur., Asia, N-Africa
Native, widespread
Myriophyllum aquaticum (Haloragaceae)
EPPO List of IAP
S-Am.
Widespread
Nymphea spp. (Nymphaeaceae)
/
/


Species which have increased their distribution in Japan rapidly in recent years:
Species
Origin
Occurrence in EPPO region
Azolla spp. (Salviniaceae)
/
/
Pistia stratiotes (Araceae) EPPO Alert List
S-Am.
Canarias (ES)
Alternanthera philoxeroides (Amaranthaceae) EPPO Alert List
S-Am.
FR, IT
Veronica anagallis-aquatica (Scrophulariaceae)
Eur., Asia, Africa, S-Am.
Native, widespread
Gymnocoronis spilanthoides (Asteraceae)
S-Am.
/
Hydrocotyle verticillata var. triradiata (Apiaceae)
S-Am.
ES
Hydrocotyle ranunculoides (Apiaceae)
EPPO A2 List
Am.
BE, DE, FR, GB, IE, IT, NL
Ludwigia repens (Onagraceae)
Am.
/


Species which have a limited distribution in Japan:
Species
Origin
Occurrence in EPPO region
Sagittaria graminea (Alismataceae)
Am.
/
Vallisneria gigantea (Hydrocharitaceae)
Am., Asia
Widespread
Heteranthera limosa (Pontederiaceae)
Am.
ES, IT (incl. Sardinia), FR, PT
Bacopa rotundifolia (Scrophulariaceae)
N-Am.
?
Lemna gibba (Lemnaceae)
Cosmop.
Native, widespread
Trapa natans var. bispinosa (Trapaceae)
Africa, Asia
/
Utricularia gibba (Lentibulariaceae)
N ; C Am.
ES, LU
Utricularia inflata (Lentibulariaceae)
N-Am.
/


Species which have been observed in the wild but did not naturalize so far:
Species
Origin
Occurrence in EPPO region
Salvinia molesta (Salviniaceae)
EPPO Alert List
S-Am.
IT, PT
Limnobium laevigatum (Hydrocharitaceae)
Am.
/
Eichhornia azurea (Pontederiaceae)
S-Am.
/
Pontederia cordata (Pontederiaceae)
Am.
ES, FR, GB, IE, IT, NL
Thalia dealbata (Marantaceae)
N-Am.
/
Heteranthera zosterifolia (Pontederiaceae)
S-Am.
/
Lagarosiphon major (Hydrocharitaceae)
EPPO List of IAP
Africa
Widespread
Hydrocleis nymphoides (Limnocharitaceae)
S-Am.
/
Neptunia oleracea (Fabaceae)
Af., Asia, Am.
/
Nymphoides aquatica (Menyanthaceae)
N-Am.
/

Sources

Kadono Y (2004) alien aquatic plants naturalized in Japan: history and present status. Global environment research 8(2), 163-169. http://www.airies.or.jp/publication/ger/pdf/08-02-07.pdf

A list of naturalized alien plants in Japan can be found in:
Mito T, Uesugi T (2004) Invasive Alien Species in Japan: The Status Quo and the New Regulation for Prevention of their Adverse Effects. Global Environmental Research 8(2), 171-191. http://www.airies.or.jp/publication/ger/pdf/08-02-08.pdf