Autumn fern, Dryopteris erythrosora is a medium to large evergreen fern growing up to about 2 ft. tall. It has short, creeping rhizomes.

Foliage

The glossy, dark green fronds are twice pinnate and up to 2 ft. long. The common name Autumn fern comes from the bright brick red color of the unfurling new fronds. Fronds turn from red to light green and then to a darker green as they mature.

Flowers

Ferns do not have flowers. The reproductive structure known as sori on the back of the fronds are a bright brick red and are a point of interest on the mature plant.

Fruit

The spores are shed from the fronds as the sori ripen. It can also spread via rhizomes.

Ecological Threat

D. erythrosora prefers rich moist woodland habitats but can withstand dryer conditions. It may be semi-evergreen in colder climates. D. erythrosora has been reported naturalized in Georgia, Kansas, and North Carolina. Native fern species use the same woodland habitats and could be displaced by D. erythrosora naturalizing in these areas.

Citations

Rawlins, K.A., R.L. Winston, C.T. Bargeron, D.J. Moorhead, and R. Carroll. 2018. New Invaders of the Southeast. USDA Forest Service, Forest Health Assessment and Applied Sciences Team, Morgantown, West Virginia. FHTET-2017-05. Retrieved from http://bugwoodcloud.org/resource/pdf/FHTET-2017-05_New%20Invaders_SE.pdf
 

Selected Images

Maps

Invasive Listing Sources

• National Park Service, Mid-Atlantic Exotic Plant Management Team Invasive Plant List
• New Invaders of the Southeast
• Non-Native Invasive Plants of the City of Alexandria, Virginia