Goldback Fern

Goldback Fern © DSchiel

Pentagramma triangularis

Description (Jepson,

    • Polypodiopsida (ferns)
      • A group of early vascular plants that produce spores (no flowers or seeds)
    • Brake / Maiden-hair Family (Pteridaceae)
    • Perennial fern
      • Grows primarily from rhizomes (horizontal underground stems)
    • Stem brown to black and smooth
    • Fronds
      • Bright green triangular frond divided into leaflets (compound) with 2 to 3 levels of division (pinnation)
      • Light yellow exudate (an excreted substance) covers the underside
    • Reproduces from spores (a small, usually single-celled, reproductive body)
      • Sori (sacs containing spores) grow on the underside of the frond
    • Height to 6 in.


      • Native to California
        • Grows in shady, rocky areas in chaparral, oak woodlands, and mixed-evergreen forests
        • See Calflora for statewide observations of this plant
      • Outside California, grows from British Columbia to Baja California, Mexico, and east to Idaho, Nevada, and Utah
      • Grows at elevations to 7,500 ft.
      Underside with Exudate and Spores © DSchiel

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

        • Dusky-footed woodrats (Neotoma fuscipes annectens) eat the fronds
        • Native people had several uses for goldback fern
          • Stems used in basketry (Mason 1904)
          • Plant used to ease childbirth afterpains and for toothaches
          • Spores used by children to make designs on their hands

        Name Derivation

          • Pentagramma (pen-ta-GRAM-ma) – from the Latin for “five lines” or “stripes”: a pentagram can be drawn from the tips of the fronds
          • triangularis (try-ang-gew-LARE-is) – from the Latin for “three sided,” referring to the general shape of the fronds
          • Goldback – refers to the light yellow color on the back of the fern created by the powdery exudate


            • The light yellow powdery substance on the underside of the fronds is not spores, but a protective covering to inhibit dehydration
            Curled Frond © DSchiel

            ID Tips

              • To distinguish goldback ferns from other Edgewood ferns, turn over the frond to see the light yellow powder (dry exudate), which will come off easily on fingers or clothing; the darker, gold-colored features are spores
              • During the dry season, frond curls up and remains; as soon as moisture is available, it un-curls

              At Edgewood

                • Found in woodlands
                  • This fern is found in wooded sections on every trail except the Sunset Trail
                  • See iNaturalist for observations of this plant
                • Grows new fronds when wet weather arrives, but may keep fronds all year

                See General References

                Specific References

                  American Fern Society. About Ferns.

                    Mason, O.T. 1904. Indian Basketry: Studies in a Textile Art Without Machinery, Volume 2. Doubleday, Page, and Co.

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