Aquatic Plants: Water Hyacinth (Eichhornia crassipes)

Origin and Date of Introduction: South America; 1884.

Pathway / Media: Waterways; nurseries and ornamental ponds.

Reason for Introduction: Deliberate; used as ornamental for 1884 World’s Industrial and Cotton Exposition in New Orleans.

Preferred Habitat: Wetlands and calm waterways.

Ecological / Economic Damage: Obstructs waterways, decreases biodiversity, creates breeding habitat for mosquitoes.

Control Options: Manual/mechanical removal, herbicides, biocontrol insects. Water hyacinth mats may double in size within one to two weeks, clogging waterways, diminishing oxygen in the water, and excluding native aquatics.

Alligator Weed

Photo: William M. Ciesla, Forest Health Management International

Futher Reading: USDA National Invasive Species Information Center