Sensitive Fern
Sensitive fern, Onoclea sensibilis, is found in many places in the Eastern United States and Midwest. There are some observations in Europe and Japan.
iNaturalist map of O. sensibilis
Sensitive fern gets its name from the fact that it withers very quickly with first autumn cold weather, sensitive to cold.
An interesting trait of O. sensibilis is that a single plant will create a fairy ring over 2-3 seasons. After the fairy ring is established, the center plant dies off. I have not seen any academic statement to this fact. In my garden I saw this trait.
Domestic, Fairfield, CT, USA
O. sensibilis has a fertile frond and a sterile frond. The fertile frond has a stipe with 'grape-like' structures on top holding the sori. The sterile fronds are pinnatifid. The fertile frond survive the winter. It is possible, in the winter, to know where to find O. sensibilis in the spring by looking for the fertile stalks sticking up above the snow.
O. sensibilis is one of the few netted ferns in New England. The veins of the pinna form a net instead of constantly branching. Netted Chain Fern is another netted fern found in New England.
Closeup of netted pattern. O. sensibilis
Fiddleheads O. sensibilis Domestic, Fairfield, CT, USA
O. sensibilis shown below after cold weather, late October.
Domestic, Fairfield, CT, USA