Brackenfern (Pteridium aquilinum)


Fern Family (Dennstaeditaceae)

Other Names:

Pteris aquilina, bracken, brake, female fern, fiddlehead, hog brake, pasture-brake, western brackenfern.

Origin and Distribution:

Brackenfern is a native species common throughout northeastern and central North America. Brackenfern is probably the largest and most common of the ferns in Ohio. It occurs in many habitats, including full sun, partial shade, woods, old pastures, roadsides and thickets, preferring acidic soils. Unlike most ferns, brackenfern is less common in rich, moist, limey areas, and thus is an indicator of poor soil.

Plant Description:

Brackenfern is a large, coarse, perennial fern that has almost horizontal leaves and can grow 1 1/2 to 6 1/2 feet tall (sometimes up to 10 feet). Unlike our more typical broadleaf perennials, this primitive perennial lacks true stems. Each leaf arises directly from a rhizome (horizontal underground stem), and is supported on a rigid leaf stalk. In addition, brackenfern does not produce flowers or seeds. Instead, it reproduces by spores and creeping rhizomes. This species often forms large colonies.

  • Root System:

    The black, scaly, creeping rhizomes (horizontal underground stems) are 1/2 inch thick, and can grow as much as 20 feet long and 10 feet deep. Stout, black, wide-spreading roots grow sparsely along the rhizomes.

  • Seedlings and Shoots:

    The curled leaves (fiddleheads) emerging from rhizomes in the spring are covered with silvery gray hair.

  • Stems:

    The leaf stalk (not a true stem) is tall (about the same length as the leaf), smooth, rigid and grooved in front. It is green when young, but turns dark brown later in the season.

  • Leaves:

    The leaf stalk supports a broad (3 feet long, 3 feet wide), triangular, dark green, leathery, coarse-textured leaf that often bends nearly horizontal. The leaf is divided into 3 parts, 1 terminal and 2 opposite. Each of the leaf parts is triangular and composed of numerous oblong, pointed leaflets, which are in turn composed of narrow, blunt-tipped subleaflets.

  • Fruits and Seeds:

    A continuous line of spore cases (spore-producing structures) is formed along the underside edge of leaflets, but the spore cases are partially or completely covered by inrolled leaf margins and are difficult to see. Spore cases produce minute, brown spores.


Spores of brackenfern are produced August through September. Brackenfern is one of the earliest ferns to appear in spring or after a fire. It sometimes forms large colonies of nearly solid stands. In the fall, it is one of the first plants to be killed by frost, resulting in large patches of crisp, brown foliage.

Brackenfern is resistant to many herbicides and is tolerant of various forms of mechanical control. However, effective control has been obtained by repeated removal of aboveground growth, which eventually exhausts the food reserves in the rhizomes.


All parts of brackenfern, including rootstocks, fresh or dry leaves, fiddleheads and spores, contain toxic compounds, and are poisonous to livestock and humans. Consumption of brackenfern causes vitamin B1 deficiency in horses, and toxins can pass into the milk of cattle. Young leaves of brackenfern have been used as a human food source, especially in Japan, and may be linked to increased incidence of stomach cancer. Humans working outdoors near abundant stands of the plant may be at risk from cancer-causing compounds in the spores.

Facts and Folklore:

  • It was once thought that if the spores of the brackenfern were gathered on St. John's Eve, it would make the possessor invisible.

  • In the 17th century, live brackenfern was set on fire in hopes of producing rain.

  • Brackenfern fiddleheads have been used as a food source; however, their consumption has been linked to various types of cancer in humans.