Pteridium

Location & distribution maps

Phylogeny & links to associated information

Wikipedia links:       Monilophytes > Polypodiales > Dennstaedtiaceae > Pteridium 

Other links:    

Species:   D esculentum

Plant  information

Common name:         Bracken 

Conservation status: . . .

Etymology:   

• From pteron, feather or wing, alluding to the shape of the leaves

• The word bracken is of Old Norse origin, related to Swedish bräken and Danish bregne, both meaning fern

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Spores:                            

• Like other ferns, brackens do not have seeds or fruits, but the immature fronds, known as fiddleheads, are sometimes eaten, although some are thought to be carcinogenic

Leaves:         

• Brackens are noted for their large, highly divided leaves

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Stem & branches: 

Roots:         

Habit:        

Habitat:   

Distribution:                  

• They are found on all continents except Antarctica and in all environments except deserts, though their typical habitat is moorland

• The genus probably has the widest distribution of any fern in the world

Species:                     

• World:        ~ 10   

• Australia:   . . .   

Additional notes:     

• Taxonomy

  • Bracken (Pteridium) is a genus of large, coarse ferns in the family Dennstaedtiaceae

  • Ferns (Pteridophyta) are vascular plants that have alternating generations, large plants that produce spores and small plants that produce sex cells (eggs and sperm)

  • In the past, the genus was commonly treated as having only one species, Pteridium aquilinum, but the recent trend is to subdivide it into about ten species

• Description and biology

  • Evolutionarily, bracken may be considered one of the most successful ferns. It is considered highly invasive, and can survive in acid soils

  • Bracken, like heather, is typically found in moorland environments, and is commonly referred to by local populations in the north of England as 'Moorland Scrub'

  • It is also one of the oldest ferns, with fossil records 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 (8.2 ft) long or longer with support, but typically are in the range of 0.6–2 m high

  • In cold environments, bracken is deciduous and, as it requires well-drained soil, is generally found growing on the sides of hills

  • Fern spores are contained in structures found on the underside of the leaf called sori

  • The linear, leaf-edge pattern of these in bracken is different from that in most other ferns, where the sori are circular and occur towards the centre of the leaf.

• Distribution wrt UK

  • 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

  • It is a prolific and abundant plant in the moorlands of Great Britain, where it is limited to altitudes of below 600 metres. It does not like poorly drained marshes or fen

  • It has been observed growing in soils from pH 2.8 to 8.6.

  • Exposure to cold or high pH inhibits its growth

  • It causes such a problem in invading pasturelands 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

  • Bracken is a characteristic moorland plant in the UK which over the last decades has increasingly out-competed characteristic ground-cover plants such as moor grasses, cowberry, bilberry, and heathers, and now covers a considerable part of upland moorland

  • Once valued and gathered for use in animal bedding, tanning, soap and glass making, and as a fertiliser, bracken is now seen as a pernicious, invasive, and opportunistic plant, taking over from the plants traditionally associated with open moorland and reducing easy access by humans

  • It is toxic to cattle, dogs, sheep, pigs, and horses, and is also linked to cancers in humans

  • It can harbour high levels of sheep ticks, which can pass on Lyme disease

  • Grazing provided some control by stock trampling, but this has almost ceased since the 2007 foot-and-mouth disease outbreak reduced commercial livestock production

  • Global climatic changes have also suited bracken well and contributed to its rapid increase in land coverage

  • Bracken is a well-adapted pioneer plant which can colonise land quickly, with the potential to extend its area by as much as 1–3% per year

  • This ability to expand rapidly at the expense of other plants and wildlife can cause major problems for land users and managers

  • It colonises ground with an open vegetation structure, but is slow to colonise healthy, well managed heather stands

  • Bracken presents a threat to biodiversity

  • Many plant species occur only on upland moorland, tied to unique features in the habitat

  • The loss and degradation of such areas due to the dominance of bracken has caused many species to become rare and isolated

Sources of information:

• https://en.wikipedia.org/wiki/Bracken (2023)