Marsh Fern - Thelypteris palustris
The pale green pinnate fronds of the Marsh Fern emerge aligned along a slender, creeping rhizome.
The frond stipe is about as long as the blade, which is lanceolate at the borders.
The edges of fertile fronds turn downwards towards the base, and, equidistant from the edge and costule, the lower page of the leaf carries small, round formations called “sori” which hold the sporangia: spores are produced from June to September.
The Marsh Fern is a plant of ancient origins, considered a floristic relict from the warm humid climate of the Tertiary Era.
In Italy, where it is known to grow in marshes, bogs, wet and humid woods, is drastically falling in numbers, particularly because its habitat is damaged more and more by human activity.
