
Photo Credit: W. Robles, Mississippi State University, Bugwood.org
Management Category
Squamish
Whistler
Pemberton
Vectors of Spread
Synonyms
- Floating water hyacinth
- Common water hyacinth
ID Characteristics
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.
Similar Species
Invasive

Water lettuce close-up, credit: Forest and Kim Starr, Starr Environmental, Bugwood.org
Water lettuce (Pistia stratiotes) is an invasive aquatic plant present in British Columbia. Water lettuce can be distinguished by its lettuce head-shaped rosette and inconspicuous white flowers. Moreover, it lacks a bulbous stem.
Non-native

Pickerelweed (Creative Commons)
Pickerelweed (Pontederia cordata) is a non-native aquatic plant present in British Columbia. Relative to water hyacinth, it has smaller leaves, forming a long, slim spike. In addition, pickerelweed leaves do not have air bladders and do not form dense mats.
Habitat and Origin
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.
How it Spreads
Water hyacinth is capable of prolific vegetative reproduction, as it sprouts daughter plants from stolons (underground stems) to create dense mats. One hectare can contain over 360 metric tons of plant biomass! Additionally, water hyacinth sometimes reproduces by seed. The seeds may germinate after being dormant for up to 28 years.
Water hyacinth disperses primarily through vegetative reproduction. However, seeds are also dispersed by wind, water and human activities. In addition, it is sometimes sold at nurseries for its showy flowers.
Interesting Fact: Water hyacinth is deemed the most damaging aquatic weed in the world. It can double its population in just 2 weeks and grow nearly 5 meters per day!
Impacts
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.
Prevent the Spread
Water hyacinth is NOT currently found in the Sea to Sky Corridor, so the best approach to controlling its spread is by PREVENTION.
This is a high-priority invasive species for the Province of BC, and it is included in the Early Detection and Rapid Response (EDRR) program.
If you see water hyacinth, please report it.
B.C. Distribution
Water Hyacinth Factsheet
Having trouble viewing the factsheet? Don’t worry, all the information is included on this page. You can also contact us with any questions.
References
- Aquatic Nuisance Species Task Force, Stop Aquatic Hitchhikers: Water Hyacinth
- Canada Commons, Water Hyacinth.
- Fraser Invasive Species Council, Water Hyacinth.
- Fraser Valley Invasive Species Society. Water Hyacinth.
- Invasive Plant Atlas, Water Hyacinth.
- Invasive Species Council of Manitoba. Water Hyacinth Factsheet.
- Ontarios Invading Species Awareness Programs, Water Hyacinth.
- USDA National Invasive Species Information Center. Water Hyacinth.