Osmunda regalis

Royal Fern

Royal Fern, Photo courtesy Wisconsin State Herbarium and Emmet J. Judziewicz
Royal Fern
Photo courtesy Wisconsin State Herbarium
and Emmet J. Judziewicz

Flora, fauna, earth, and sky...
The natural history of the northwoods


  • Osmunda, from the Saxon god Osmunder the Waterman, Saxon equivalent of the Norse god Thor, who hid his family from danger in a clump of these ferns.
  • regalis, from the Latin, "royal"
  • Common Name, from the botanical name
  • Other common names include: Kungsbräken, Safsa (Swe), Dugosz Królewski (Pol), Felce Florida (It), Raineach Rìoghail (Gaelic)


  • Kingdom Plantae, the Plants
    • Division Polypodiophyta, the True Ferns
      • Class Filicopsida
        • Order Polypodiales
          • Family Osmundaceae, the Flowering Ferns (an oxymoron, of course)
            • Genus Osmunda, the Flowering Ferns
  • Taxonomic Serial Number: 17218
  • Also known as Osmunda spectabilis
  • Osmunda ferns form spores on a modified frond. For this species, a spore-bearing frond grows from the rhizome separate from sterile fronds.


  • A large, atypical fern of lakeshores and wet places, up to 6' tall.
  • Fronds doubly compound and not fern-like in appearance
    • Petioles (leaf stalks) roughly the length of blades, winged, with light brown hairs, smooth at maturity
    • Blades alike, except that fertile fronds have greatly reduced sporangia-bearing pinnae at tip. Golden brown in Fall.
    • Pinnae (primary leaflets) 6 pairs or more, widely spaced and lanceolate.
    • Pinnules (secondary leaflets) 8 pairs or more, widely spaced; narrow and oblong, with short stalks and blunt to rounded tips. Highly variable.
  • Rootstalk large, upright, with remmants of old stalks; tussock forming.
    • Roots black, wiry, and often quite deep in ground.
    • Fiddleheads smooth, burgandy, and rather stout. Prominent in spring.
  • Sporangia greenish, turning red, then rusty brown.


  • Distinguished from all other native ferns by its large size and decidedly unfern-like sterile fronds.
  • Field Marks
    • Doubly compound frond
    • Widely spaced leaflets and subleaflets
    • Spores borne in reduced leaflet at tip of fertile frond


  • variety spectabilis - Ontario to Newfoundland, south to the Gulf of Mexico and from the Atlantic coast west to the edge of the prairie in Minnesota, Iowa, Missouri, eastern Oklahoma, and East Texas. Also Colombia and Venezuela, south to Ecuador, Bolivia, and Peru.
  • variety regalis - Africa from Morocco and Algeria to South Africa; Eurasia from Norway to Russia, south to Eire, Iberia, Sicily, Greece, Turkey, the Caucasus.







  • Reproduces by spores and vegetatively by crown expansion


  • By spore or division.


  • Hardy to USDA Zone 3 (average minimum annual temperature -40ºF)
  • Cultural Requirements
    • Needs some shade
    • Soil pH 4.3-5.2
    • Moist to wet
  • Grows from crown rather than runners, so the plant spreads slowly.
  • Good for edge of pond or bog garden
  • Available by mail order from specialty suppliers or at local nurseries
  • Tolerates some sun if given adequate moisture, but really does better in light shade.



  • Look for prominent clumps of Royal Fern on lakeshores throughout the BWCA.
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Last Updated on 26 February, 2004