Coastal Wood Fern

Coastal Wood Fern © TCorelli

California Wood Fern, Coast Wood Fern, Coastal Woodfern
Dryopteris arguta

Description (Jepson,

Sori with Indusia © DSchiel
  • Fern (Polypodiopsida) 
    • Ferns are a group of vascular plants that produce spores (reproductive cells)
      • Produce no flowers or seeds
      • Fossil records date back almost 400 million years, versus 130 million years for flowering plants
  • Wood Fern Family (Dryopteridaceae)
  • Perennial herb
    • Stress deciduous
    • Grows from rhizomes (horizontal underground stems)
  • Fronds
    • Lanceolate, up to 24 in. long and 7 in. wide at base
    • Compound (divided into leaflets), with usually 2 levels of division (2-pinnate)
    • Leaflet tips are toothed or bristled
    • Lower part of stalk (petiole) without leaflets and with some scales
  • Sori 
    • Sori (singular: sorus) are clusters of spore-producing, sac-like structures called sporangia (singular: sporangium)
    • Located on the underside of leaflets in parallel rows, either side of the midrib
    • Protected by a tissue flap called an indusium (plural: indusia)


  • Native to California
    • Grows on shaded slopes in a variety of habitats, including oak woodlands, mixed evergreen forests, and chaparral
    • See Calflora for statewide observations of this plant
  • Outside California, grows along west coast from British Columbia south to Baja California, Mexico and into Arizona
  • Grows at elevations to 8,200 ft.

Uses (San Mateo County Parks prohibits removal of any natural material)

  • Food for dusky-footed woodrats (Neotoma fuscipes annectens)
  • Native people had many uses for coastal wood fern
    • Rhizomes gathered in spring for food
    • Decoction of roots made to treat vomiting and internal bleeding
    • Fronds used to clean meat and to cover meat to keep off flies
    • Infusion of fronds used as a hair wash
    • Spores used to make designs on hands

Name Derivation

  • Dryopteris (dry-OP-ter-is) – from the Greek drys, “oak,” referring to habitat, and pteris, “fern”
  • arguta (ar-GOO-ta) – from the Latin for “sharp,” referring to the leaflet tips


  • Deer resistant
  • Associated with the fungus-like microorganism Phytophthora ramorum, which causes Sudden Oak Death (SOD)
    • At Edgewood, the two species known to be highly susceptible to SOD are coast live oak (Quercus agrifolia var. agrifolia) and Pacific madrone saplings (Arbutus menziesii)
    • For a complete list of known hosts and host associates see USDA Risk Analysis for Phytophthora ramorum, pp. 6-9

ID Tips

  • May be confused with western sword fern (Polystichum munitum)
    • Coastal wood fern
      • Fronds have 2 levels of division
      • Is common along woodland trails at Edgewood
    • Western sword fern
      • Fronds have 1 level of division
      • Is not seen on any Edgewood trails, though they can be spotted on the hillside at the back of the Day Camp
  • Unlike other ferns at Edgewood, leaflets are often angled, like half-closed blinds

At Edgewood

  • Common in woodlands
  • Grows year round

See General References

Specific References

American Fern Society. About Ferns.

U.S. Forest Service, United States Department of Agriculture. What Are Ferns?.