Water Hyacinth

General: Water hyacinth is a herbaceous evergreen perennial in the Pontederiaceae family.

Flowers: Showy flower spikes composed of 4 – 15 individual flowers. Each flower has 6 purple to pink petals. The upper petal displays a darkened spot with a yellow center.

Stems: Bulbous and spongy, growing up to 50 cm long.

Leaves: Kidney-shaped leaves with inflated bases form free-floating rosettes. They are thick, waxy and glossy. Leaves are 10 – 20 cm wide and contain air bladders for floatation.

Roots: Long, dark purple to black roots dangle below the rosette. Roots are highly divided and appear feather-like. As much as 50% of water hyacinth’s biomass is found in the roots.

Fruits: Thin-walled, ribbed capsules contain as many as 450 egg-shaped seeds.

Native to South America and the Amazon basin. Introduced to North America as an ornamental in the 1880s.

The aquatic plant favours nutrient-rich waters and warm climates. It frequently inhabits shallow ponds, lakes, wetlands slow-flowing waterways, and rivers. In the Pacific Northwest, it is often planted outdoors in pools and water features, but is not considered winter hardy.

Ecological:

• Outcompetes and displaces native vegetation, which reduces biodiversity.
• Reduces oxygen levels in water, altering the entire aquatic ecosystem.
• Decreases overall water quality by releasing heavy metals and other pollutants.
• Creates a favourable habitat for mosquitoes.

Economic:

• Forms dense floating mats that slow water flow and block irrigation canals, increasing maintenance costs.
• Dense mats also disrupt recreational activities.