Royal Fern
Royal fern, Osmunda spectibilis, is found in many places in the Eastern United States and Midwest. There are some observations in Europe and Japan.
A very similar species is Osmunda regalis. O. spectibilis and O. regalis used to be varieties of a species. Now, as of 2023 (possibly PPG II, 2016), they are two different species.
iNaturalist.org map of O. spectibilis
O. spectibilis is found in the Eastern and Southern United States. Observations in Mexico.
The pinna are spread out and quiet lobed. O. spectibilis looks 'primitive' as the frond is very simple in shape, very triangular. No wavy margin. Simple bipinnate. A lot of space between pinna.
Kent Land Trust, Kent, CT, USA (Laurie Doss)
The sori are found on the tips of the fertile fronds. The sori structure is brown and 'floppy' once mature.
Fairfield, CT, USA
Sori are erect when immature easily seen at the tip of the frond. Fairfield, CT, USA
O. spectibilis likes to have its feet wet.
Fairfield Audubon, Fairfield, CT, USA
O. spectibilis in late October.
Domestic, Fairfield, CT, USA