Osmunda(redirected from osmundas)
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a genus of perennial ferns of the family Osmundaceae. The stems are massive and usually short; they are topped by a crown of large leaves measuring as much as 3 m long. The pinnate leathery or filmy leaves are divided into vegetative and spore-bearing parts. Sometimes there are separate vegetative and spore-bearing leaves. There are about 15 species, growing in humid and swampy regions, primarily in the subtropics of Eurasia, Africa (including Madagascar), and the Americas. The USSR has three species. The royal fern (O. regalis), with leaves up to 1.5 m long, occurs in western Transcaucasia; the two other species are found in the Far East. Some species are ornamental.