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] 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.

Alternanthera philoxeroides can thrive in both dry and aquatic environments[4] and is characterized by whitish, papery flowers along its short stalks, irregular, or sprawling hollow stems, and simple and opposite leaf pattern sprouting from its nodes.

[5] Alternanthera philoxeroides is considered a major threat to ecosystems because of the adverse effects it poses on both aquatic and terrestrial environments, as well as the negative influence it has on society.

[5] These compact clusters of stems also disturb the regular exchange of gases that occurs underneath the surface that directly influences aerobic processes, such as photosynthesis.

[citation needed] This invasive plant depends solely on vegetative means to reproduce and disperse itself in the area it has invaded and established its roots.

[3] In effort to eradicate the species by manual means, such as mulching or pulling them out, if not removed efficiently, small stem fragments can be displaced to new areas.

[citation needed] Early detection is the best bet to ensure that the invasive species does not successfully colonize a non-native region because of its ability to regenerate and propagate from small portions of its stem or leaf cuttings.

The most successful and widely used is Agasicles hygrophila commonly called the alligator weed flea beetle; it has been released for biocontrol in Australia, China, Thailand, New Zealand, and the United States.

[4] A variety of chemicals have been shown to be effective in controlling the plant, the most useful of which include glyphosate, triclopyr, fluridone, imazamox, and imazapyr; however, they must constantly be applied to be successful.