Montane, subalpine. Woodlands, openings. Spring.
Above: Hillside Drive, north of Cortez, July 30, 2018 and West Mancos Trail, October 14, 2022.
Left: Lizard Head Trail, June 9, 2006 and June 16, 2016.

Bracken is often found in large colonies, frequently in the shade of Aspens.  Most other ferns in our area are quite small and dainty but Bracken is often 4-7 feet tall and each plant is several feet wide, often overlapping its neighboring Bracken forming a lacy thicket. 

The young Bracken Ferns in the top photograph at left are three feet tall and growing quickly; the even younger Bracken Fern in the second photograph at left is only fourteen inches tall. The two photographs were taken in exactly the same location, but the spring of 2016 had much more snow than the spring of 2006 and the lingering snow and cooler temperatures resulted in about a two weeks difference in plant growth. 

Bracken reproduces almost exclusively by root growth, not by spores.  Bracken’s roots are deep, making it very hardy and relatively impervious to drought or excesses of heat or cold.  It is thus our most common fern and, in fact, it is one of the world’s most common ferns.

The genus was named by Gleditsch in 1760 and the species was named by Kuhn in 1879 after Linnaeus had named it Pteris aquilina in 1753.

"Pteridium" is from the Greek "pteron", meaning "fern", and from Pteris, a genus of ferns. The "idium" ending is a diminutive and indicates that the genus Pteridium is a bit like the genus Pteris. "Aquilinum" is from the Latin for "eagle" and refers to the large wing-like fronds of this very large fern.

Montane, subalpine. Woodlands, openings. Spring.
Bear Creek Trail, June 6, 2014 and
Lizard Head Trail, June 9, 2006.

Oh, fiddleheads.

Pteridium aquilinum contains cyanogenic glycosides which break down to cyanides in animals (including human animals).  Our digestive system can break down small amounts of cyanides, such as those we might get from a few apple or pear seeds or a tiny amount of ferns, but larger amounts can lead to everything from "feeling bad", to breathing difficulties, to kidney failure, to death.  Even though some people continue to eat the very young, washed, and then boiled fiddleheads of this and other ferns, there is considerable doubt regarding the safety of eating this plant.

See the Hong Kong produced web page on "Food Safety Topics" for the 2014 article on the carcinogens of Pteridium aquilinum.

Montane, subalpine. Woodlands, openings. Spring.
Lizard Head Trail, September 15, 2010 and West Mancos Trail, October 2, 2012.

Bracken Ferns have subtle and lovely shades of yellows and browns in the fall.

Range map © John Kartesz,
Floristic Synthesis of North America

State Color Key

Species present in state and native
Species present in state and exotic
Species not present in state

County Color Key

Species present and not rare
Species present and rare
Species extirpated (historic)
Species extinct
Species noxious
Species exotic and present
Native species, but adventive in state
Eradicated
Questionable presence

Range map for Pteridium aquilinum