JACKSON, Wyo. — Teton County Weed & Pest District (TCWP) needs help from the public to find phragmites and to prevent further spread in Teton County.
Phragmites (Phragmites australis subsp. australis), or common reed, is an invasive, riparian grass that can grow from 6 to 20 feet tall. It is a prolific seed producer with as many as 2,000 seeds in each panicle. These seeds may be dispersed by wind or water. Phragmites also produces stolons and rhizomes (reproductive shoots) that enable this species to form dense stands. These stolons and rhizomes may also be transported to new locations as contaminants in soil, landscaping materials, or construction equipment. By creating dense stands, phragmites alters wetland hydrology, reduces plant and animal diversity, increases fire risk, and prevents access to riparian habitat.
Phragmites was first identified in Teton County in 2023. Since that time, TCWP staff and the public have identified phragmites in 27 locations throughout the county. Phragmites has been found in natural riparian areas and in developed landscapes indicating that this species may be spreading by wildlife and human activities.
While phragmites is an invasive species, there is also a native subspecies (Phragmites australis subsp. americanus). Differentiating between the species and subspecies is difficult in the field. However, a recently developed, rapid, and relatively simple laboratory test allows for in-house testing of phragmites. After a report of phragmites is received, TCWP visits the site, collects samples of the vegetation, and utilizes a PCR-RFLP assay developed by Wendell et al. (2021) to determine if the sample is the invasive or native subspecies or a hybrid of the two. Of the 27 known locations of phragmites in Teton County, only one has been identified as the native subspecies.
TCWP needs help to prevent further spread of this species and to find any locations in the county. Some ways Teton County residents, visitors, and developers can help include:
- Join WYLD watch and report phragmites to TCWP (download the EDDMaps app or use the report infestation form at tcweed.org).
- Clean shoes and gear before and after recreating.
- Brush pets after hiking and check fur for seeds.
- Clean construction equipment before and after entering a site.
- Use certified weed free materials as available and check soil and plant materials for contaminants before installation.
Additional information on phragmites, the PCR-RFLP assay, and invasive species in Teton County may be found at tcweed.org.
Contact: Lesley Beckworth, Landowner & Outreach Coordinator, Lbeckworth@tcweed.org.
1Wendel, Douglas L., et al. 2021. A simple screen to detect hybrids between native and introduced Phragmites australis in the United States and Canada. Journal of Great Lakes Research. 47(5): 1453-1457
