Pteridium aquilinum – Western bracken fern

At a Glance

  • Family: Dennstaedtiaceae
  • Plant type: fern
  • Distribution: native to the lower US states, Alaska and Hawaii, and Canada, and found on all continents (except Antarctica). One of the most widely distributed plants in the world.
  • Habitat: grows well in many habitats from woodlands to open pastures and burnt-out areas, and moist to slightly dry soils. Manages both shade and sunny locations.
  • Height: 2-4’
  • Spores: reproductive sori with spores are found along the underside edges of the leaflets. The plants can also spread through a rhizome network
  • Leaves: broad light green fronds up to 3’ long, one frond is made of many divided leaflets, rounded edges on each leaflet. Frond is generally triangular in shape and 2-3 times pinnate.
  • Generation: perennial, dies back with frost
  • Notable features: bracken release allelopathic chemicals (biochemicals that influence germination/growth/reproduction/survival of other organisms) that suppress the growth of other plants

Restoration and Conservation

  • As bracken fern is mildly toxic, few bugs or animals eat it
  • It easily establishes in disturbed, high light environments and can create monospecific stands

Ethnobotany/Commercial Use

  • Commonly eaten by the people of western Washington to provide starch and fiber. Bracken rhizomes were crushed down into a flour, with methods varying between groups, then baked or dried into cakes and bread
  • The rhizomes themselves could also be roasted, dried and stored, or eaten fresh
  • Studies have indicated the presence of carcinogenic compounds in bracken, with consumption by humans possibly increasing the risk of stomach or throat cancer
  • Usually not planted in home gardens because of its allelopathic chemicals. Best placed in isolated areas where it can form clumps/stands
  • Can tolerate intense heat well, so it can be planted near asphalt driveways. However, bracken fern is also able to force its way through several inches of asphalt.

Resources

For questions regarding the St. Edward State Park EERC Native Plant Guided Tour, contact Sarah Verlinde-Azofeifa at severlin@uw.edu.