About Phragmites

Phragmites australis subsp. australis, also known as European common reed, is a tall, densely growing perennial grass that can take over large areas, displacing native vegetation and reducing habitat quality for fish and wildlife. It can be found in wetlands, riparian areas, shorelines, and other wet areas such as roadside ditches and stormwater ponds. Both native and non-native genotypes of Phragmites are present in Minnesota. The native and non-native types can be confusing to distinguish from one another. For this reason, non-native Phragmites has been dubbed a “cryptic” invader. Without coordinated efforts to distinguish and map native and non-native forms, the true distribution of invasive Phragmites in the state cannot be determined. This gap poses two risks: lack of action in response to new invasions or indiscriminate treatment that damages the native subspecies.

What it affects

Invasive Phragmites is an ecosystem engineer that benefits from human-caused disturbances on the landscape. Invasive populations in North America have been shown to alter wetland hydrology, lower plant diversity, impact food webs, and reduce diversity and abundance of invertebrates, fish, and waterbirds.

Where it's found

Phragmites has a global distribution, being found on all continents except Antarctica. The lineage that is invasive in North America – from the Atlantic coast westward to Minnesota and beyond – is native to Europe. This form has spread across North America over the past 150+ years, almost entirely displacing native Phragmites in regions where it has long been established.

See the map of verified Phragmites populations in Minnesota generated by University of Minnesota researchers and their collaborators.

How it spreads

Invasive Phragmites can spread both sexually (by seed) and asexually (clonally, including by stolons or “runners”, root-like structures called rhizomes, and stem fragments). When populations produce large amounts of viable seed, spread across the landscape is more rapid and control is more difficult and expensive. The extent of sexual reproduction in Minnesota was investigated via viability studies, which showed that viable seed is being developed in several populations in approximately the southern two-thirds of the state.