Pteridium esculentum, commonly known as bracken fern, Austral bracken or simply bracken, is a species of the bracken genus native to a number of countries in the Southern Hemisphere. Esculentum means edible. First described as Pteris esculenta by German botanist Georg Forster in 1786,[1] it gained its current binomial name in 1908.[2] The Eora people of the Sydney region knew it as gurgi.[3]
Morphology
P. esculentum grows from creeping rhizomes, which are covered with reddish hair. From them arise single large roughly triangular fronds, which grow to 0.5–2 metres (1 ft 8 in – 6 ft 7 in) tall. The fronds are stiff with a brown stripe.[4]
Like its northern hemisphere relatives, Pteridium esculentum is very quick to colonise disturbed areas and can outcompete other plants to form a dense understorey. It is often treated as a weed. It does create a more humid sheltered microclimate under its leaves and is food for a variety of native insects.[7] Two species of fruit fly (Drosophila) were recorded in a field study near Sydney.[8] Another study near Sydney yielded 17 herbivorous arthropods (15 insects and two mites), notable for the lack of Hymenoptera (ants, bees, wasps, and sawflies) and beetles.[9]
Uses
The Māori of New Zealand used the rhizomes of Pteridium esculentum (aruhe) as a staple food, especially for exploring or hunting groups away from permanent settlements; much of the widespread distribution of this species in present-day New Zealand is in fact a consequence of prehistoric deforestation and subsequent tending of aruhe stands on rich soils (which produced the best rhizomes).[10] The rhizomes were air-dried so that they could be stored and became lighter; for consumption, they were briefly heated and then softened with a patu aruhe (rhizome pounder); the starch could then be sucked from the fibers by each diner, or collected if it were to be prepared for a larger feast. Patu aruhe were significant items and several distinct styles were developed.[10]
Indigenous people in Australia ate the roots after they were pounded into a paste and roasted.[3]
Pteridium esculentum contains the known bracken carcinogen ptaquiloside.[11] Concentrations of ptaquiloside in bracken in New Zealand vary greatly, and in a high proportion of stands ptaquiloside is not found. A higher incidence of ptaquiloside, and some very high concentrations, are found in areas where bovine enzootic haematuria and/or acute haemorrhagic syndrome was known to occur.[12]
^Mesibov, Bob. "Bracken and Bugs". The Unique Flora of Tasmania. Hobart District Group of The Australian Plants Society - Tasmania Inc. Archived from the original on 18 September 2010. Retrieved 22 June 2010.
^Fletcher M.T., Hayes P.Y., Somerville M.J., De Voss J.J."Ptesculentoside, a novel norsesquiterpene glucoside from the Australian bracken fern Pteridium esculentum". Tetrahedron Letters. 51 (15) (pp 1997-1999), 2010.
