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)
      • Sporangia sacs split open to catapult mature, microscopic spores, which are wind dispersed
    • 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)

  • Wildlife
    • Food for dusky-footed woodrats (Neotoma fuscipes annectens)
  • Native people
    • 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


  • Wildlife
    • Resistant to deer browsing
    • 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.

Pai, A. 2018, Dec. 28. Fantastic ferns and where to find them. Bay Nature.

U.S. Forest Service. What are ferns? Forest Service. United States Department of Agriculture.