Bracken fern

Prepared by Jennifer L. D’Appollonio, Assistant Scientist, University of Maine, Orono, ME 04469. March 2011.

Scientific name: Pteridium aquilinum (L.) Kuhn

Common name(s): Bracken fern, brackenfern, western brackenfern, bracken, western bracken, common bracken

Links: USDA PLANTS Profile, NPIN Profile, Go Botany

Images: (to see enlargements [PC]: click on image, then right click and choose “view image”)


– perennial

-family Pteridaceae

-deciduous fern

-can reach up to 2 m in height

-stout, cylindrical petioles up to 1 m long

-fifth most distributed common weed species of the world

-Reproduces by spores and creeping rhizomes (some up to 18′ long)

-Rigid leaf stalk 1′-3′ long, and swollen at base

-leaves are

  • blades 2′-4′ long and 1′-3′ wide
  • triangular to oval shaped
  • with or without hairs on the underside
  • spores in light brown masses on the underside of the leaf blade.

-The sporangia ripen from July to September

-noxious weed

-contains different poisonous agents: some cyanogen glycosides and factors of carcinogenic activity

– two subspecies in New England, ssp. latiusculum and ssp. pseudocaudatum; see Flora Novae Angliae information at bottom of Go Botany webpage


-grows and spreads successfully on many types of soils

-open woods

-pine forests

-silicate substrates



Haines, A., Farnsworth, E., Morrison, G., & New England Wild Flower Society. (2011). New England Wildflower Society’s Flora Novae Angliae: A manual for the identification of native and naturalized higher vascular plants of New England. Framingham, MA: New England Wild Flower Society. p. 54.

Vetter, J. (2009). A biological hazard of our age: Bracken fern [pteridium aquilinum (L.) kuhn]–a review. Acta Veterinaria Hungarica (Budapest. 1983), 57(1), 183-196. doi:10.1556/AVet.57.2009.1.18

Alonso-Amelot, M. E., & Rodulfo-Baechler, S. (1996). Comparative spatial distribution, size, biomass and growth rate of two varieties of bracken fern (pteridium aquilinum L. kuhn) in a neotropical montane habitat. Vegetatio, 125(2), 137-147. doi:10.1007/BF00044647