Imagine a time when dinosaurs had mysteriously disappeared, and only little rat-like mammals ruled the planet. Then imagine these small animals scurrying around under bracken fern. The same bracken fern that line our lightly shaded forest floors and edge our fields. Maybe their green fronds are what make our landscape seem so pristine and primeval. Bracken fern are one of the most common global-wide plants known, one species growing in the Northern hemisphere, another in the Southern hemisphere.
You can’t miss bracken fern. It has two fern-like fronds emerging from an upright single, frond-topped rigid stalk. When newly emerged, the fronds are soft and pliant. As they age, they toughen making a walk in shorts through a colony of bracken an unpleasant, scratchy experience. This large fern grows knee-high or taller, and is most often found in partial shade to sunny, dry locations. Matter of fact, you won’t find it in waterlogged soils or heavily shaded areas where you expect to find ferns.
Bracken is a pioneer plant. It can grow on many types of soils, and the soil’s acidity or alkalinity doesn’t seem to matter. Wind-born spores allow it to quickly inhabit newly disturbed soils. It will be one of the first to start growing after a fire has swept through an area. Its dried fronds cover the ground in fall. This dried material helps fuel incipient fires and insure bracken’s survival by burning away competition while its rhizome root enables it to survive the same fire. This rhizome also forms the stalk, which is not the hollow ‘stem’ of most herbaceous perennials plants.
During bracken’s long survival it has evolved methods to ensure its continued existence. These methods do not make it a garden friendly plant. It secretes chemicals into the soil that inhibit the growth of neighboring plants. Chemicals in its leaves kill or inhibit the growth of insects. The plant invades crop fields, competing for the soil’s nutrients and moisture. It can poison cows and horses grazing on its fronds. Research has shown eating bracken can produce tumors in animals; the only plant known to have this capability.
Resistant to many herbicides, the only reliable way to eradicate bracken from an area is to repeated cut the above ground growth. This weakens the rhizome and eventually kills it.
An important crop used to thatch roofs and fuel a quick fire in Medieval Europe, today bracken is a human food crop. The emerging tightly curled fronds or fiddleheads are considered a delicacy raw, cooked, salted or pickled. It has been used as an ingredient of beer, the ground rhizome dried and ground for flour, and it is still used in parts of the world as an herbal remedy. Yes, despite the carcinogenic results of tests on lab animals and ties to leukemia and cancers of various digestive organs in humans.
To its credit, with its poisonous traits, bracken may become the source for new insecticides.
Their rhizomes extract phosphorus and transmute it into a type more readily available to plants, so the presence of bracken can indicate a nutrient rich soil. The fronds are sensitive to acid rain and act as an indicator of air pollution.
Long ago someone thought this upright, triangular arrangement of fronds made this fern look like an eagle. Bracken’s botanical name Pteridium aquilinum reflects this, aquilinum meaning ‘eagle-like.’ The genus name ‘Pteridium,’ derives from the Greek word for fern, and bracken comes down from Old English for any fern, but the word applied in particular to this fern. Its survival is more certain than that of its namesake.