Bracken

Description:

Evolutionarily, bracken may be considered to be one of the most successful ferns. It is also one of the oldest, with fossil records of over 55 million years old having been found. The plant sends up large, triangular fronds from a wide-creeping underground rootstock, and may form dense thickets. This rootstock may travel a metre or more underground between fronds. The fronds may grow up to 2.5 m (8 ft) long or longer with support, but typically are in the range of 0.6–2 m (2–6 feet) high. In cold environments bracken is winter-deciduous, and, as it requires well-drained soil, is generally found growing on the sides of hills.

Habitat:

Pteridium aquilinum (Bracken or Common Bracken) is the most common species with a cosmopolitan distribution, occurring in temperate and subtropical regions throughout much of the world, including most of Europe, Asia, and North America in the Northern Hemisphere, and Australia, New Zealand and northern South America in the Southern Hemisphere. It is a prolific and abundant plant in the highlands of Great Britain. It is limited to altitudes of below 600 metres in the UK, does not like extreme cold temperatures, poorly drained Marshes or Fen. It causes such a problem of invading pastureland that at one time the British government had an eradication programme. Special filters have even been used on some British water supplies to filter out the bracken spores.[1] NBN distribution map for the United Kingdom

Notes:

The plant is carcinogenic to animals such as mice, rats, horses and cattle when ingested, although they will usually avoid it unless nothing else is available. Young stems are quite commonly used as a vegetable in China, Japan and Korea. However, some researchers suspect a link between consumption and higher stomach cancer rates.[4] The spores have also been implicated as a carcinogen. Danish scientist Lars Holm Rasmussen released a study in 2004 showing that the carcinogenic compound in bracken, ptaquiloside or PTQ, can leach from the plant into the water supply, which may explain an increase in the incidence of gastric and oesophageal cancers in bracken-rich areas.[7] In cattle, bracken poisoning can occur in both an acute and chronic form, acute poisoning being the most common. In pigs and horses bracken poisoning induces vitamin B deficiency.[8] Poisoning usually occurs when there is a shortage of available grasses such as in drought or snowfalls.