HPIPM:Brackenfern

Taxonomy

Domain	Eukarya
Kingdom	Plantae
Division	Pteridophyta
Class	Polypodiopsida
Order	Polypodiales
Family	Dennstaedtiaceae
Genus	Pteridium

Scientific Name

Pteridium aquilinum

Common Name

brackenfern

Brackenfern(Pteridium aquilinum)

Compiled by: Jack Stivers, Montana State University, Lake County Extension

and Marjolein Schat, Montana State University from the following sources:

http://plants.usda.gov/java/profile?symbol=PTAQ

http://www.oardc.ohio-state.edu/weedguide/singlerecord.asp?id=10

http://www.fs.fed.us/database/feis/plants/fern/pteaqu/all.html

Identification and Life Cycle

Brackenfern (Pteridium aquilinum) is a native perennial in the fern family (Polypodiaceae). Other common names for brackenfern include bracken, brake, female fern, fiddlehead, hog brake, and pasture brake. Brackenfern is a large, coarse fern that has almost horizontal leaves and can grow 1 1/2 to 6 1/2 feet tall. Brackenfern lack true stems. Each leaf arises directly from a rhizome and is supported on a rigid leaf stalk. In addition, brackenfern does not produce flowers or seeds. 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. The curled leaves (fiddleheads) emerging from rhizomes in the spring are covered with silvery gray hair. The leaf stalk is tall (about the same length as the leaf), smooth, rigid and grooved in front. It is green when young, but turns dark brown as it matures. Each leaf stalk supports a broad (3 feet long, 3 feet wide), triangular, dark green, leathery, coarse-textured leaf. The leaf is divided into 3 parts, 1 terminal and 2 opposite parts. Each of the leaf parts is triangular and composed of numerous oblong, pointed leaflets, which are in turn composed of narrow, blunt-tipped subleaflets. 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.

Habitats

Brackenfern occurs in many habitats, including full sun, partial shade, woods, old pastures, roadsides and thickets. Brackenfern prefers acidic soils. Unlike most ferns, brackenfern is less common in rich, moist, limey areas.

Impacts

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. Wildlife can, however, eat brackenfern in the spring prior to unfurling of the leaves.

Biology and Ecology

Brackenfern reproduces by spores and creeping rhizomes, although most regeneration appears to be vegetative. Brackenfern is one of the earliest ferns to appear in spring or after a fire. Young brackenfern plants can produce spores by the end of the second growing season in cultivation but normally do not produce spores until the third or fourth growing season. Spores are produced from August through September. A single, fertile frond can produce 300,000,000 spores annually. Spore production varies from year to year depending on plant age, frond development, weather, and light exposure. Brackenfern sometimes forms large colonies of nearly solid stands and, it is one of the first plants to be killed by frost, resulting in large patches of crisp, brown foliage. Brackenfern's aggressive rhizome system gives it the ability to reproduce vegetatively and reduces the plant's dependence on water for reproduction. The rhizomatous clones can be hundreds of years old, and some clones alive today may be over 1,000 years old. Rhizomes have a high proportion of dormant buds. When disturbed or broken off, all portions of the rhizome may sprout, and plants growing from small rhizome fragments revert temporarily to a juvenile morphology.

Management Approaches

Timing is important in any treatment of bracken fern. The most effective time for treatment is summer just after the new fronds have fully expanded and starch reserves in the rhizome are at their lowest level. Two or more annual treatments and combinations of cutting and herbicide are more effective than single treatments or even single annual treatments.

Biological Control

Biological methods for control of western bracken fern in Great Britain are being investigated and two South African moths appear promising. The possibility of using disease fungi, either alone or in conjunction with herbicides, to control brackenfern is also being studied. However, no biological control agents are currently available.

Mechanical and Cultural Control

Effective control has been obtained by repeated removal of aboveground growth, which eventually exhausts the food reserves in the rhizomes. Cutting early in the summer, allowing the rhizomes to regenerate a second crop of fronds, then recutting will deplete the resources of the rhizome much faster than a single cutting. However, single, annual cuttings or deep plowing can be effective during midsummer.

Chemical Control

A number of herbicides are labeled for use on brackenfern.

Examples of herbicides that can be used to manage brackenfern

Consult herbicide labels for additional rate, application, and safety information. Additional herbicide information can be found at http://www.greenbook.net.

Due to constantly changing labels, laws and regulations, the sponsors of this web site assume no liability for the suggested use of any chemicals noted in the management section. Contact your local pest management personnel for current information on labeled pesticides that can be used for the intended plant disease, insect pest or weed.

References

For more information and images please visit IPM Bugwood. http://www.ipmimages.org/search/action.cfm?q=brackenfern&Start=1&results=39