Suppression

Bracken

Category: Medicines - plant based

Type

Voluntary

Introduction and description

 

Pteridium aquilinum is the botanical name of bracken, brake or common bracken, a species of fern that is treated as a weed, and universally reviled by farmers and gardeners alike for being extremely invasive, where it has succeeded in destroying grassland and heather moorland alike.

Despite being a native of the UK, for example, it is treated as an invader and campaigns are run to try to rid the countryside of it. 

Numerous attempts have been made to stop its progress in the Peak Park of the UK,  for example, in the heather (Calluna vulgaris (L.) Hull) stands on the North Yorkshire moors and on our coastline, with the National Trust calling on volunteers to help in manual clean up.

It is one of the world’s great survivors, and it is in this ability to survive that we get an inkling of its major use, of which more in a moment.

It is very widely distributed. 

 

It can be found in temperate and subtropical regions in both hemispheres.

The extreme lightness of its spores has led to its global distribution.  Those same spores can cause very severe lung infections in cattle and horses, and the plant is poisonous to many species of animals, as such it has no real predator.

Burn it and it comes back with renewed vigour. 

Bracken is classified as a herbaceous perennial plant, deciduous in winter. The large, roughly triangular fronds are produced singly, arising upwards from an underground rhizome, and grow to 1–3 m (3–10 ft) tall; the main stem, or stipe, is up to 1 cm (0.4 in) diameter at the base.  Try and dig it out and if even a tiny part remains, it will regrow.

 

Common bracken was first described as Pteris aquilina by Carl Linnaeus, in Volume 2 of his Species Plantarum in 1753. The origin of the specific epithet derived from the Latin aquila "eagle", but what it pertains to has been a matter of some debate. It is generally held to be the shape of the mature fronds appearing akin to an eagle's wing. However, medieval scholars, including Erasmus, thought the pattern of the fibres seen in a transverse section of the stipe resembled a double-headed eagle or oak tree. It was given its current binomial name by Friedrich Adalbert Maximilian Kuhn in 1879.

It was traditionally treated as the sole species in the genus Pteridium (brackens); authorities have split and recognised up to 11 species in the genus.

 

You can’t or at least shouldn’t eat it.

The plant contains the carcinogenic compound ptaquiloside, and communities (mainly in Japan) where the young stems are used as a vegetable have some of the highest stomach cancer rates in the world.

Consumption of ptaquiloside-contaminated milk is thought to contribute to human gastric cancer in the Andean states of Venezuela.

The spores too have also been implicated as carcinogens.

So why on earth is it on the site?

And the answer is that it is one of the most robust bioremedial plants we have.  In situations believed hopeless, bracken appears to be able to thrive.  It can fix toxic soils to stop them blowing around and causing more damage and it sucks up toxins as if it was nursed on them. 

The fronds contain the toxins, so the plant can be scythed down and the fronds carefully carted away and buried a mile deep until the ground is clean.

There is no such thing as a useless plant.

Remembering that bracken thrives on toxins, we should also bear in  mind that the spread of bracken may be a symptom .......

References and further reading

  • Epidemiology of intoxication of domestic animals by plants in Europe.  Cortinovis C, Caloni F.  Vet J. 2013 Aug;197(2):163-8. doi: 10.1016/j.tvjl.2013.03.007. Epub 2013 Apr 6. Review.  PMID:  23570777
  • The environmental and human effects of ptaquiloside-induced enzootic bovine hematuria: a tumorous disease of cattle.  Sharma R, Bhat TK, Sharma OP.  Rev Environ Contam Toxicol. 2013;224:53-95. doi: 10.1007/978-1-4614-5882-1_3. Review.  PMID:  23232919
  • Norsesquiterpene glycosides in bracken ferns (Pteridium esculentum and Pteridium aquilinum subsp. wightianum) from Eastern Australia: reassessed poisoning risk to animals.  Fletcher MT, Brock IJ, Reichmann KG, McKenzie RA, Blaney BJ.  J Agric Food Chem. 2011 May 11;59(9):5133-8. doi: 10.1021/jf104267c. Epub 2011 Apr 12. PMID: 21456622
  • Morphological factors as indicators of malignancy of squamous cell carcinomas in cattle exposed naturally to bracken fern (Pteridium aquilinum).  Masuda EK, Kommers GD, Martins TB, Barros CS, Piazer JV.  J Comp Pathol. 2011 Jan;144(1):48-54. doi: 10.1016/j.jcpa.2010.04.009. Epub 2010 Jun 9.  PMID:  20542519
  • A biological hazard of our age: bracken fern [Pteridium aquilinum (L.) Kuhn]--a review.  Vetter J.  Acta Vet Hung. 2009 Mar;57(1):183-96. doi: 10.1556/AVet.57.2009.1.18. Review.  PMID:  19457786
  • Investigation of a syndrome characterised by passage of red urine in smallholder dairy cattle in East Usambara Mountains, Tanzania.  Karimuribo ED, Swai ES, Kyakaisho PK.  J S Afr Vet Assoc. 2008 Jun;79(2):89-94.  PMID:  18846854
  • Suspected bracken poisoning in pigs.  Harwood DG, Palmer NM, Wessels ME, Woodger NG.  Vet Rec. 2007 Jun 30;160(26):914-5. PMID:  17602110
  • Bracken fern (Pteridium aquilinum) poisoning in cattle in southern Brazil.  Gava A, da Silva Neves D, Gava D, de Moura ST, Schild AL, Riet-Correa F.  Vet Hum Toxicol. 2002 Dec;44(6):362-5.  PMID:  12458643
  • Malignant catarrhal fever in cattle with suspected bracken poisoning.  Twomey DF, Holt GJ, Reid HW.  Vet Rec. 2002 Oct 19;151(16):486-7. PMID:  12418535
  • Human carcinogenesis and bracken fern: a review of the evidence.  Alonso-Amelot ME, Avendaño M. Curr Med Chem. 2002 Mar;9(6):675-86. Review.  PMID:  11945131
  •  [Recent plant poisoning in ruminants of northern and eastern Germany. Communication from the practice for the practice].  Schrader A, Schulz O, Völker H, Puls H.  Berl Munch Tierarztl Wochenschr. 2001 May-Jun;114(5-6):218-21. German.   PMID:  11413718

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