"brasiliensis", (formerly "Osmunda regalis" var. "Osmunda regalis" produces separate fertile and sterile fronds. "Osmunda regalis" is widely cultivated in temperate regions. Rare ferns present include marsh fern ("Thelypteris palustris") and royal fern ("Osmunda regalis"). Certain true ferns, e.g., "Osmunda regalis" have sporangia in tight clusters which may appear flower-like. The sterile (vegetative) fronds resemble in form, another relative, "Osmunda regalis" (Royal fern).