Osmunda spectabilis
Osmunda spectabilis, known as American royal fern, is a species of fern native to a large area of the New World, from Canada to Argentina. Description. "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. The fronds of "O. spectabilis" can exceed 1 meter in length and are bipinnate. The pinnules are attached by a very narrow base. The plant produces separate sterile and fertile fronds. Fertile fronds are similar to  the sterile fronds, in the lower and middle portions, but the top-most pinnae are fertile and they are much reduced and brown when mature in the early summer. Distribution and habitat. American royal fern is most commonly found growing in wetter soils such as those found in wet forests, bogs, and along streams and lakes. Taxonomy. "Osmunda spectabilis" was formerly considered to be a variety of "Osmunda regalis" ("Osmunda regalis" var. "spectabilis"). Another variety, "Osmunda spectabilis" var. "brasiliensis", (formerly "Osmunda regalis" var. "brasiliensis") also exists in tropical regions of Central and South America, but it is only recognized by  some authors. "Osmunda angustifolia", "Osmunda bromeliifolia", and all extinct "Osmunda" species are missing from this cladogram. The classification is based on the genetic analysis presented in "The Paraphyly of "Osmunda" is Confirmed by Phylogenetic Analyses of Seven Plastid Loci."