• Tall wetland grass species that grows up to 6 meters high. Found throughout the U.S.
• Considered invasive particularly along the Atlantic Coast and much of the Midwest.
• Spreads by means of rhizomes that can reach down almost 2 meters below ground.
• Forms monotypic stands (200 stems per square meter) that crowd out native plants and reduce wildlife habitat.
• See: Invasive Phragmites Video

• Frogbit is a free-floating aquatic herb that grows in marshes, ditches and swamps. Its miniature, heart-shaped leaves resemble those of water lilies.
• Common to the temperate regions of Eurasia, Frogbit is considered an invasive plant in Canada and was identified in wetlands near Lake St. Clair (U.S. side) in 2000.
• Frogbit forms dense mats on the surface of the water that can impede water traffic and reduce growth of native submersed aquatic plants.

Hydrilla
Hydrilla verticillata
(potential Great Lakes invasive species)

• Hydrilla is a submerged aquatic plant that has invaded waterways in at least 19 U.S. states. If hydrilla spreads to Michigan, it could quickly overwhelm waterways, causing severe ecological and economic impacts.
• Hydrilla can grow up to an inch per day. It forms large, dense mats near the surface of the water that block recreational access, impede drainage and restrict water movement, causing sediment to accumulate.
• Thick mats of hydrilla block sunlight and can suffocate native plants and animals that live in the waters below.
• Learn more about Hydrilla.

• Purple loosestrife is a tall, flowering plant native to Europe that has invaded many North American wetlands and every watershed in Michigan.
• Thick stands of purple loosestrife block access to water, overtake native wetland plants and reduce food and habitat for wildlife.
• Management of purple loosestrife using biological control is beginning to reduce the invasive plant in some areas of Michigan.
• See the Purple Pages web site.