DESCRIPTION: Water hyacinth plants grow floating on the water surface, forming stolons. Plants have very prominent black, stringy roots. Plants sometimes grow stranded in mud and appear rooted. The leathery leaves appear basal, are suborbicular, ovate or broadly elliptic with parallel veins; bases are heartshaped, square, or rounded, apices rounded or flattened. Petioles are usually spongy-inflated. The inflorescence is a spike with light-blue to bluish-purple showy flowers marked with yellow streaks. The fruit is many seeded.

PATHWAYS/HISTORY: This species is found in the southern U.S., Virginia to southern Florida, west to Missouri, Texas and California. Plants grow in ponds, canals, rivers, ditches, and impoundments, reproducing by vegetative runners or stolons. Seeds do germinate and produce new plants in some part of the species range. Water hyacinth is commonly planted intentionally for its decorative flowers.

RISKS/IMPACTS: Plants are notorious for clogging and desiccating canals and waterways in the southern U.S. By forming new plantlets, a population can completely dominate and obstruct a body of water in a short period of time. Native species are excluded, and large populations may affect water quality.

MANAGEMENT: Biocontrol agents (weevils and a moth) are having a significant impact on waterhyacinth populations.

WHAT YOU CAN DO: Do not intentionally plant this species in water gardens or ponds. Never release garden or pond ornamental plants into the wild. Clean all equipment that comes in contact with waters thought to harbor this species. Do not take or move any aquatic vegetation.

PROFILE CREDIT: David Webb, USACE - IMAGE CREDIT: NOAA