While planning a group trip to the Carolinas and area for this spring, I’ve been revisiting some of my photographs from last year. This is a tentative identification for the subject fern in this image. If someone wants to assert that it is instead a species of Athyrium from the area (see A Natural History of Pearson’s Falls and Some of Its Human Associations for a species list), I could be swayed. Unfortunately, the foreground stream along with considerations for the rental car (wet shoes) and the property (Pearson’s Falls) precluded a closer look.
Dryopteris marginalis is endemic to eastern North America, extending southwest from the southern tip of Greenland to Kansas and Oklahoma. According to the Flora of North America for Dryopteris marginalis, it is a species of “Rocky, wooded slopes and ravines, edges of woods, stream banks and roadbanks, and rock walls”. It appears to me that this plant is periodically submerged by the stream during periods of high waterflow.
The etymology of the specific epithet is explained by HardyFernLibrary.com (Dryopteris marginalis): “Marginalis means margined, referring to the position of the sori”. A photograph illustrating the location of these spore-producing receptacles on the frond is also available on that site, or on the Ferns and Fern Allies of Wisconsin: Dryopteris marginalis.