Bracken (or Pteridium aquilinum) is the largest (approx. 6ft) and most commonly found fern in the U.K. Its widespread distribution is indicated by its occurrence in dozens of the NVC communities.   Bracken is found in a wide range of habitats (though it does not ‘like’ wet and is only found at sites below 600M.) Bracken ‘prefers’ dry, somewhat acid soils though it can grow in a fairly wide pH range.  It spreads by means of its underground rhizomes (modified underground stems), sometimes at a rate of one metre per year.   On bare ground (for example, after burning), it can establish itself by spores,  produced in sori (reproductive structures) on the underside of the leaves / fronds. Often bracken is a pioneer species.  It has been described as 'the perfect weed'. Bracken spores may be found in the cores taken for pollen analysis; these indicate that bracken has a long history in the U.K. landscape. Peaks of bracken spores are associated with loss of woodland cover in the last 2000 years, though there is some evidence for a decline in bracken in the 14th Century – which featured a number of cold (and wet) decades (the Black Death was rampaging across Europe). Read more...