California Maidenhair Fern

California Maidenhair Fern © DSchiel

Adiantum jordanii

Description (Jepson,

Stems © KKorbholz
  • Polypodiopsida (ferns)
    • A group of early vascular plants that produce spores (no flowers or seeds)
  • Brake / Maiden-hair Family (Pteridaceae)
  • Perennial fern
    • Grows from short creeping rhizomes (horizontal underground stems)
  • Fronds
    • Divided into leaflets (compound) with 2 levels of division (pinnation)
    • Leaflets (leaf-like structures of compound leaf) are round or fan-shaped, slightly lobed, and finely-toothed
  • Stems are dark brown to black, smooth, and wiry
  • Reproduces from spores (a small, usually single-celled, reproductive body)
    • When mature, leaflet margins roll under, hiding 1-5 sori (sacs containing spores)
  • Height generally 8-18 in.


  • Native to California
    • Grows in soil and rock crevices on shaded hillsides and in moist woodlands
    • See Calflora for observations of this plant
  • Outside California, grows from Oregon to Baja California, Mexico
  • Grows at elevations to 3,775 ft.

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

  • Native people had a variety of uses for California maidenhair fern
    • Decoction of the plant used for internal pain, purifying blood, and expelling afterbirth (California Ohlone)
    • Stems used to keep pierced ears from closing or as ear decoration (California Pomo)
    • Used roots for binding baskets and stems for basket designs

Name Derivation

  • Adiantum (ad-ee-AN-tum) – from the Greek for “unwettable,” referring to the fronds shedding water
  • jordanii (JOR-dun-ee-eye) – a tribute to Rudolf Jordan, Sr. (1818-1901), a German immigrant to California, who collected this fern and had it identified by German botanist Karl Mueller, who named the species after Jordan
  • Maidenhair – implies fine hairs, which may refer to the slender stems or the many fine roots


  • New fronds grow at the beginning of the wet season and dry up in late fall
  • Host to the fungus-like microorganism Phytophthora ramorum, which causes Sudden Oak Death (SOD)
    • At Edgewood, the 2 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

  • To distinguish from other Edgewood ferns, look for fan-shaped, delicate leaflets

At Edgewood

  • Found in woodlands on moist, shaded hillsides and stream banks

See General References

Specific References

    American Fern Society. About Ferns.

      Anthropology Museum, California State University, Sacramento. Enduring Traditions: Baskets in Native California, a Mobile Classroom Outreach Trunk.

        California Department of Parks and Recreation. 2019. California Indian Baskets.

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