Currently not present in Michigan
Common Name: Water Hyacinth
Scientific Name: Eichhornia crassipes
Water hyacinth is a floating aquatic plant that is around 2-3 feet tall. It has thick cup-shaped leaves that grow to be 4-8 inches wide with air bladders for floatation. Its large purplish pink flowers each have 6 petals measuring 2-3 inches each. Water hyacinth grows rapidly and forms dense heavy mats. Infestations can double in size every two weeks, and seeds remain viable for over 20 years.
Water hyacinth was introduced to North America in 1880’s as an ornamental plant. It originated in the Amazon River Basin but now there are isolated patches in Midwest, including Lake St. Claire and the Detroit River area. Typically the plant prefers calmer water bodies.
Water hyacinth spreads mostly by stolons (runners) and fragmentation, but also by roots and seeds. It clogs waterways and impedes boating, fishing, swimming, etc. It forms such dense mats that it even crowds and shades out native vegetation, harming native plants and other aquatic life. Just one acre of the plant can weigh 200 tons. Biocontrol using certain insects has been somewhat effective to control the plant’s spread.
A similar species to the Water hyacinth is Pickerelweed (Pontaderia cordata), but it isn’t free-floating and does not have air bladders. Its purple flowers are much smaller (<1/2”).
Water hyacinth grows rapidly and forms dense heavy mats that restrict swimmers and boaters, prevent other recreational uses of waterways, and reduce biodiversity by crowding out native plants and preventing sunlight from reaching submerged plants.
To Report Water Hyacinth
If you believe you have found invasive Water Hyacinth (or another invasive species), you can report the sighting to Tip of the Mitt Watershed Council at (231) 347-1181 or e-mail firstname.lastname@example.org.
MISIN Mobile App Reporting
You may also report invasive species using the free mobile smartphone app from Midwest Invasive Species Information Network (MISIN).