Osmunda spectabilis, known as American royal fern, is a species of fern native to a large area of the New World, from the eastern half of Canada and the United States to Argentina.

[2][3] Osmunda spectabilis is an easy fern to recognize in the New World flora.

Although it closely resembles species O. regalis, O. japonica, and O. lancea, only O. spectabilis is found growing naturally in the New World.

brasiliensis) also exists in tropical regions of Central and South America, but it is only recognized by some authors.

The classification is based on the genetic analysis presented in "The Paraphyly of Osmunda is Confirmed by Phylogenetic Analyses of Seven Plastid Loci.