What Are Brackens?

A class of ferns, brackens are one of the oldest known plants, with fossil specimens dating 55 million years. It is one of most successful, widespread plants, absent only in dry deserts and the continent of Antarctica. Derived from the Scandinavian word for “fern,” the common name is reserved for the plant family Dennstaedtiaceae. At one time, they were broadly classified in the genus Pteridium, but they are identified in about ten different genetic species.

Brackens are characterized by their large triangular, and highly articulated leaf structure, called fronds. Each can grow to more than 8 feet (2.4 meters) long. The plants are correspondingly large, from around 3.3 to 9.8 feet (1 to 3 m) tall. Their primitive vascular stems can measure 0.4 inches (1 cm) in diameter. Also characteristic, the fronds develop as tight curls of plant tissue that unfurl and expand to mature size.

Like most ferns, a bracken is a perennial herbaceous plant. It lacks the tough cambium tissue of woody plants. Unlike annuals, which die each growing season, brackens’ reproductive cycle dictates that they survive two or more years. In alternating years, they reproduce both sexually and asexually. Two gamete cells with identical chromosomes, sperm and ovary, fuse, and the following year multiply into single-celled spores lining the underside of fronds, to be distributed by wind.

The spores propagate underground as a rootstock called a rhizome. Individual plants shoot from this root. Environmentally, brackens serve as a low canopy for creatures and plants that benefit from the extra cover and shade. Ecologically, they are food for many insect larva. Uncontrolled, they are an aggressive and invasive plant.

Part of brackens’ extraordinary evolutionary success is their secretion of allelopathic chemicals. The complex compounds, released into surrounding soil, are toxic and inhibit the germination of other competing plant species. Some of these chemicals are potentially natural insecticides and herbicides.

Brackens are also food for humans. The delicacy commonly called fiddleheads, eaten either raw, cooked, or pickled, are the plant’s curled immature leaves. Their rootstock is used to brew beer; also dried and ground to a starchy flour. In Japan, the flour is baked into cakes and confections. In Korea, fiddleheads are steamed with rice into the common dish called bibimbap.

The ferns were a staple for native Maori of New Zealand, and brackens have been used as an herbal remedy against parasitic worms of the digestive tract. Ingested brackens, however, are a proven carcinogen in some laboratory animals, perhaps because of their spores. Consumed raw in excess, they can cause a condition commonly called beriberi, an atrophy and paralysis of the body’s nervous, circulatory, and digestive systems. Although studies have proven inconclusive, even cooked and moderately consumed plants are suspected agents of fatal stomach cancer.

Brackens are a type of large, coarse fern that belong to the genus Pteridium. They are known for their extensive rhizome systems and triangular fronds, which can grow up to 3 meters tall. Brackens are found worldwide and are particularly common in woodland areas and moors, where they can form dense thickets.

While brackens are a natural component of many ecosystems, they can become invasive, outcompeting native vegetation and reducing biodiversity. Their dense growth can inhibit the regeneration of trees and other plants. Additionally, brackens produce chemicals that can be toxic to livestock and other plant species, further impacting local flora and fauna.

Historically, brackens have had various uses. They've been used as bedding for livestock, as a source of potash for soap and glass making, and even as a food source in times of scarcity. However, due to their potential toxicity, they are not commonly used for culinary purposes today.

Yes, brackens can be toxic. They contain compounds such as ptaquiloside, which can be carcinogenic and harmful if ingested in large quantities. These toxins can pose risks to livestock that graze on brackens and have been linked to cancers in animals. Humans should also avoid consuming bracken or using it in traditional medicinal practices.

Brackens reproduce both sexually and asexually. They produce spores on the undersides of their fronds, which can be dispersed by wind to germinate and grow into new plants. Additionally, their extensive underground rhizome systems can give rise to new shoots, allowing them to spread rapidly over large areas.

Controlling bracken growth can be challenging due to their extensive rhizome networks. Methods include cutting or crushing the fronds to deplete the rhizomes, applying herbicides, and encouraging grazing by livestock, which can help suppress new growth. In some areas, controlled burning is used, but this must be done carefully to avoid damaging other wildlife.