Plantae > Tracheophyta > Magnoliopsida > Caryophyllales > Amaranthaceae > Alternanthera > Alternanthera philoxeroides

Alternanthera philoxeroides (alligator weed; alligatorweed; pig weed; Xi han lian zi cao)

Synonyms: Achyranthes paludosa; Achyranthes philoxeroides; Alternanthera philoxerina; Alternanthera philoxeroides f. phyllantha; Alternanthera philoxeroides var. acutifolia; Alternanthera philoxeroides var. obtusifolia; Brandesia martiana; Bucholzia philoxeroides; Bucholzia philoxeroides var. obtusifolia; Celosia amphibia; Mogiphanes philoxeroides; Telanthera philoxeroides; Telanthera philoxeroides var. acutifolia; Telanthera philoxeroides var. denticulata; Telanthera philoxeroides var. obtusifolia; Telanthera philoxeroides var. phyllantha

Wikipedia Abstract

Alternanthera philoxeroides, commonly known as alligator weed, is an emergent aquatic plant. It originated in Argentina in 1897, but has spread to many parts of the world and is considered an invasive species in Australia, China, New Zealand, Sri Lanka, Thailand, and the United States. The alligator weed's primary mode of transport is believed to be through ballast tanks on the side of traveling ships.
View Wikipedia Record: Alternanthera philoxeroides


Invasive Species

Alternanthera philoxeroides, commonly known as alligator weed, is a perennial stoloniferous herb that can be found in many parts of the world, infesting rivers, lakes, ponds and irrigation canals, as well as many terrestrial habitats. The aquatic form of the plant has the potential to become a serious threat to waterways, agriculture and the environment. The terrestrial form of Alternanthera philoxeroides grows into a dense mat with a massive underground rhizomatous root system. The canopy can smother most other herbaceous plant species. It has proven to be extremely expensive to attempt controlling Alternanthera philoxeroides.
View ISSG Record: Alternanthera philoxeroides


Height [1]  3.9 inches (0.1 m)
Screening - Summer [1]  Porous
Screening - Winter [1]  Porous
Hardiness Zone Minimum [1]  USDA Zone: 6 Low Temperature: -10 F° (-23.3 C°) → 0 F° (-17.8 C°)
Light Preference [1]  Mixed Sun/Shade
Soil Acidity [1]  Neutral
Soil Fertility [1]  Infertile
Water Use [1]  High
Flower Color [1]  White
Foliage Color [1]  Green
Bloom Period [1]  Early Spring
Drought Tolerance [1]  Low
Fire Tolerance [1]  None
Frost Free Days [1]  6 months 20 days
Fruit/Seed Begin [1]  Spring
Fruit/Seed End [1]  Summer
Growth Form [1]  Stoloniferous
Growth Period [1]  Spring
Growth Rate [1]  Rapid
Leaf Type [2]  Evergreen
Lifespan [1]  Perennial
Propagation [1]  Sprig
Regrowth Rate [1]  Slow
Root Depth [1]  10 inches (25 cm)
Seed Spread Rate [1]  None
Shape/Orientation [1]  Prostrate
Structure [2]  Herb
Vegetative Spread Rate [1]  Rapid


Name Countries Ecozone Biome Species Report Climate Land
Eastern Coastal Australia Australia Australasia Tropical and Subtropical Coastal Rivers    
Lower Mississippi United States Nearctic Temperate Floodplain River and Wetlands    
Sabine - Galveston United States Nearctic Temperate Coastal Rivers    

Protected Areas

Name IUCN Category Area acres Location Species Website Climate Land Use
Canaveral National Seashore II 9090 Florida, United States
Carolinian-South Atlantic Biosphere Reserve 310228 North Carolina, South Carolina, Georgia, United States      
Central Gulf Coastal Plain Biosphere Reserve 40530 United States  
De Soto National Wildlife Refuge IV 8007 Iowa, Nebraska, United States
Defensores del Chaco National Park II 1792493 Paraguay  
El Palmar National Park II   Entre Rios, Argentina  
Everglades and Dry Tortugas Biosphere Reserve   Florida, United States  
Gulf Island National Seashore II 67487 Florida, Mississippi, United States
Hobcaw Barony (North Inlet) National Estuarine Research Reserve 7585 South Carolina, United States
Lacassine National Wildlife Refuge VI 28351 Louisiana, United States
Río Pilcomayo National Park II 123699 Formosa, Argentina
Reserva de Biosfera del Chaco   Paraguay      
Reserva Natural Otamendi Strict Nature Reserve Ia   Buenos Aires, Argentina  
Santee Coastal Reserve and Washo Reserve State Habitat Area IV 20850 South Carolina, United States  


Agasicles hygrophila (Alligatorweed flea beetle)[3]
Amynothrips andersoni (alligator weed thrips)[4]
Hypolimnas bolina (Great egg fly butterfly)[5]
Junonia almana (Peacock Pansy)[5]
Junonia atlites (Gray Pansy)[5]
Vogtia malloi (alligator weed stem borer)[5]


Caribbean; North America;



Attributes / relations provided by
1USDA Plants Database, U. S. Department of Agriculture
2Kattge, J. et al. (2011b) TRY - a global database of plant traits Global Change Biology 17:2905-2935
3Agasicles hygrophila Selman and Vogt (Coleoptera: Chrysomelidae: Halticinae), Ted D. Center, USDA-ARS Invasive Plant Research Laboratory; James P. Cuda, University of Florida; Michael J. Grodowitz, U.S. Army Engineer Research and Development Center, September 2009. Latest revision: November 2015
4Amynothrips andersoni O'Neill (Insecta: Thysanoptera: Phlaeothripidae), Ted D. Center (retired), USDA-ARS Invasive Plant Research Laboratory; James P. Cuda, University of Florida, Entomology and Nematology Department; Michael J. Grodowitz, US Army Engineer Research and Development Center, June 2010. Last Revision: April 2013
5HOSTS - a Database of the World's Lepidopteran Hostplants Gaden S. Robinson, Phillip R. Ackery, Ian J. Kitching, George W. Beccaloni AND Luis M. Hernández
Ecoregions provided by World Wide Fund For Nature (WWF). WildFinder: Online database of species distributions, ver. 01.06 WWF WildFINDER
Images provided by Google Image Search
Abstract provided by DBpedia licensed under a Creative Commons License
Weather provided by NOAA METAR Data Access