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Taxon  Report  
Alternanthera philoxeroides  (Mart.) Griseb.
Alligator weed,   Alligatorweed
Alternanthera philoxeroides is a perennial herb that is not native to California.
Cal-IPC rating: high
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Observation Search
~420 records in California
redone or more occurrences
within a 7.5-minute quadrangle

Bloom Period
Genus: Alternanthera
Family: Amaranthaceae  
Category: angiosperm  
PLANTS group:Dicot
Jepson eFlora section: eudicot

Wetlands: Occurs in wetlands

Communities: wetland-riparian

Name Status:
Accepted by JEF + PLANTS

Alternate Names:
PLANTSAchyranthes philoxeroides
Information about  Alternanthera philoxeroides from other sources

[plants.ifas.ufl.edu] Native to South America.Habitat & habits: Native to: South America Alligatorweed was accidentally introduced into Florida in 1894 in ships' ballast water and can now be found growing throughout the state. This rooted perennial plant can grow in various habitats, although it is usually found in water. It forms sprawling mats over deep rivers or along shorelines and can be a pest on land. (contributed by Mary Ann Machi)

[Wikipedia] History & negative impacts: Alternanthera philoxeroides, commonly referred to as alligator weed, is a native species to the temperate regions of South America, which includes Argentina, Brazil, Paraguay and Uruguay.[2] Argentina alone hosts around 27 species that fall within the range of the genus Alternanthera.[2] Its geographic range once covered only the Parana River region of South America, but it has since expanded, having been introduced to over 30 countries, such as the United States, Japan, China, Australia, New Zealand and many more.[3] This invasive species is believed to have been accidentally introduced to these non-native regions through sediments trapped by, or attached to, tanks and cargo of ships travelling from South America to these various areas. (contributed by Mary Ann Machi)

Suggested Citation
Calflora: Information on California plants for education, research and conservation, with data contributed by public and private institutions and individuals. [web application]. 2024. Berkeley, California: The Calflora Database [a non-profit organization]. Available: https://www.calflora.org/   (Accessed: 04/12/2024).