Eastern Marsh Fern

Thelypteris palustris belongs to the family Thelypteridaceae and is distributed across regions including Portugal, Belgium, the United States, and parts of Eurasia. It thrives in moist, wet environments such as fresh tidal and nontidal marshes, wet fields, and wooded streambanks. The plant is notable for its ecological role as the only known host of the marsh fern moth, Fagitana littera. First described in 1834 by Schott, it is widely recognized for its habitat-specific adaptations and is found in a range spanning from Portugal to Bermuda and as far east as Altay. The species is commonly referred to as Eastern Marsh Fern in English and shares the same common name in the target language.