Montana Field Guide

Najas marina is an aquatic plant that was first detected in Montana in 2018 at Frenchtown Pond State Park in Frenchtown (Freeman and Pfingsten 2021). Plants were discovered during surveys conducted by Montana Fish, Wildlife & Parks through the Aquatic Invasive Species Program. On-going surveys through 2021 have confirmed that plants are present in two ponds where populations appear to be abundant and healthy (Freeman personal communication). These observations along with an unpublished 2014 report in Idaho extend its range and represent the first documented locations for the Pacific Northwest (Freeman and Pfingsten 2021; U.S. Geological Survey 2022). Previously, the closest records were found in Minnesota, southeastern North Dakota, Nebraska, California, Nevada, and Utah (Freeman and Pfingsten 2021). Plants likely arrived either through non-motorized recreational activities or by waterfowl. Control strategies include containment and eradication. A conservation status rank is not applicable (SNA) because exotic plants are not a suitable target for conservation activities.

NOTE: It is important to document new occurrences by providing quality plant specimens to one of our State herbaria (University of Montana, Montana State University, or Montana State University-Billings). Herbarium specimens allow identifications to be confirmed, provide a central location for education and information sharing, are a source for conducting genetic, morphological, and ecological studies, and are the basis on which Montana's floras are written.