Another variety, "Osmunda spectabilis" var. "Osmunda", "Plenasium", and the recently described "Claytosmunda" with the single species, "Osmunda claytoniana". "brasiliensis", (formerly "Osmunda regalis" var. "Claytonia virginica" and "Osmunda claytoniana". "Osmunda regalis" is widely cultivated in temperate regions. "Osmunda regalis" produces separate fertile and sterile fronds. The species was first described in 1753 by Carl Linnaeus as "Osmunda spicant". The species was first described by Carl Linnaeus in 1753, as "Osmunda claytoniana". There are three very similar species, "Osmunda spectabilis", "Osmunda lancea" and "Osmunda japonica". Rare ferns present include marsh fern ("Thelypteris palustris") and royal fern ("Osmunda regalis"). "Osmunda angustifolia", "Osmunda bromeliifolia", and all extinct "Osmunda" species are missing from this cladogram. "Osmunda spectabilis" is an easy fern to recognize in the New World flora. "Osmunda" evolved in the ancient southern continent of Gondwana. The name "Osmunda" possibly derives from "Osmunder", a Saxon name for the god Thor. Osmunda is a genus of primarily temperate-zone ferns of family Osmundaceae.