Native vs. Non-Native

Stands of native Phragmites exist across the Great Lakes basin. Native Phragmites is frequently found in wetlands with high biodiversity and also supplies food and nesting resources for wetland residents. Care is needed before and during management of non-native Phragmites to avoid impacting its native counterpart.

When managing non-native Phragmites, it is important to first determine if the plants in question are the native or invasive strain, both to protect native plants from harm and to avoid wasting invasive species management resources on a non-target species.

Where Is Native Phragmites Found?

According to the University of Michigan herbarium records, native Phragmites has been documented in 30 out of the 83 Michigan counties. Many of these records are decades old, so its current extent is less well understood. Through a brief and informal survey of land managers and some on-the-ground scouting, USGS and partners have identified five additional patches in southeast Michigan. Our search was in no way comprehensive, but our findings indicate that native Phragmites is much more common than we had initially anticipated. At some of these sites, non-native Phragmites was also present and, in some cases, growing right alongside the native haplotype. These findings raise some very interesting scientific questions, but also heighten the concern of accidental treatment of native Phragmites when targeting non-native Phragmites.

 

The chart to the right provides a brief overview of characteristics to look for when distinguishing between native and non-native Phragmites. Source: Michigan Department of Natural Resources Best Practices for Phragmites Management guide. Click on the image to enlarge.

Tips on distinguishing between native and non-native Phragmites

The following are few quick pointers to help distinguish between the two while in the field:

Color: Side by side, the leaves of the invasive appear bluish, while native leaves are more yellow (this determination is difficult to make when you only have one haplotype at hand); live stems of invasive are dull green, whereas native stems frequently appear reddish or purplish.

leaf and stems

The picture at left show leaves from invasive (top) and native (bottom) Phragmites australis plants. The picture on the right shows the red stems from native P. australis. Photo credits: Katherine Hollins

Leaf persistence: on dead non-native stems, leaf sheaths are difficult to remove, whereas on dead native stems, leaf sheaths are easily removed or fall off by themselves.

Ligule length: Non-native ligules are approximately half the length of native ligules (0.1-0.4 mm for invasive haplotype compared to 0.4-1.0 mm for native).

Density: Stands of non-native Phragmites are typically very large, tall, and dense (i.e. hard to walk through easily) while native stands are usually integrated with a more diverse plant community and not as dense.

phrag densities

The pictures above show different growth patterns of invasive and native Phragmites. The left side of the photo shows a very dense senesced growth of invasive Phragmites, as opposed to the picture at right which displays the sparse stems of native Phragmites growing alongside other wetland species. Photo credits: Wes Bickford and Katherine Hollins

There are many resources online and in print to help aid in distinguishing between the two haplotypes. Some great examples can be found at:

To confirm our morphological identification of the native plants we found during this fall’s field work, we sent leaf tissue to Dr. Doug Wendell at Oakland University. Doug analyzed DNA polymorphisms in both the native and non-native strains to further distinguish between the two using the methods of Saltonstall (2004).

Doug gel

The above graphic is of the resultant gel showing the DNA polymorphisms between invasive and native Phragmites. The invasive DNA is not cut by the RsaI digest, but is cut by the HhaI digest, whereas the native is cut by the RsaI digest, and not cut by the HhaI digest

Genetic Diagnostic Services

If you need genetic confirmation for whether your Phragmites is native or invasive, then consider contacting one of the following cooperating laboratories:

  • Doug Wendell, Ph.D, wendell@oakland.edu Oakland University, Rochester, MI: This lab conducts genetic testing to confirm the lineage of Phragmites.
  • Karen Mock, Ph.D, karen.mock@usu.edu Utah State University, Logan, UT: This lab conducts genetic testing to confirm the lineage of Phragmites.

 

Additional Resources: Handouts and Guides

Phragmites: Native or Not? 

A brochure by Michigan Sea Grant

Phragmites Field Guide: Distinguishing between native and exotic forms of Common Reed (Phragmites australis) in the United States

By Jil Swearingen and Kristen Saltonstall (2010)

Additional Resources: Videos

Native or Introduced? Identification of Phragmites lineages in North America

This 30-minute video by Dr. Kristin Saltonstall with the Smithsonian Tropical Research Institute provides great detail on the identifying characteristics of native and non-native Phragmites, including characteristics that should not be used. Published in 2015.

VIDEO: Dr. Dan Carter Explains How to Identify Native Phragmites

By the Southeastern Wisconsin Regional Planning Commission (2016)