Also known as Eagle Fern, Brake, Pasture Brake, Bracken Fern
Common bracken dominates open woodlands and pastures with its massive, triangular fronds that unfurl from deep, fire-resistant rhizomes. This ancient fern releases millions of microscopic spores that drift on the wind, allowing it to colonize disturbed soils across nearly every continent. Its dense canopy shades out competing flora, while its chemical defenses deter most herbivores.
ThreatsNone (highly resilient and often considered an invasive weed)
HabitatsWoodlands, pastures, heaths, moorlands, and disturbed soils
Life spanPerennial (individual fronds die annually, rhizomes can live for decades)
Size / weightNot available
Classification
FamilyDennstaedtiaceae
SpeciesPteridium aquilinum
Range & activity
Range data is not available yet.
Safe observation
Interaction riskHigh
Low
Moderate
High
Very high
Why interaction risk is high
All parts contain carcinogenic toxins; do not ingest any part, including young fiddleheads.
Why it is dangerous
Contains ptaquiloside, a potent carcinogen, and thiaminase, which causes severe vitamin deficiency in livestock.
How to recognize a risky encounter
Recognized by its large, triangular, three-part fronds growing from individual underground stems rather than circular crowns.
What to do
Do not consume any part of the plant, and wash hands after handling mature fronds to avoid ingesting spores.
Responsible observation
Identify by structure: Look for the distinctive three-branched, triangular fronds that rise individually from the ground rather than in circular clumps.
Observe seasonal changes: Watch the bright green fronds turn a rich golden-brown in autumn, providing winter cover for small wildlife.
Avoid harvesting: Do not collect the fiddleheads for food due to high concentrations of natural carcinogens.
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