As Christmas approaches our thoughts may turn to Mistletoe, though its place in our culture almost certainly pre-dates the Christian era. It is a semi-parasitic plant that grows on trees with characteristically leathery leaves and white, sticky, spherical berries.  It photosynthesises with its green leaves but it also lives partly off the tree into which it sinks its specially adapted roots.  It has tiny flowers from February to April and berries from September into January.  The characteristic tight ball-like growths result from the fact that its stem repeatedly forks into two.

A striking infestation of Mistletoe growing on a Horse Chestnut in the garden of The Timbralls, Eton, in April 2019.

Widely distributed across southern England and Wales, it is spread from tree to tree by birds which feed off the white berries and then wipe the viscous material, including the seed, off their beaks and onto branches.  It needs a mild, humid climate and trees with relatively soft bark.  Mistletoe will grow on a range of hosts, but the usual host trees are Lime, Apple, Hawthorn and Willow.  Most Mistletoe for sale these days is imported from northern France, especially from Poplars in Picardy and the orchards of Normandy and Brittany.

As Richard Mabey notes in his excellent book, Flora Britannica: ‘Looking at mistletoe against a low winter sun – the great tresses glistening the colour of tarnished brass, the tiers of twigs like wishbones, the whole plant’s unearthly vitality in the lifeless trees – it is not hard to imagine how it became one of the most revered plants of early herbalists.’  No wonder, then, that in the Middle Ages, it was credited with magical powers and credited with the power to improve human fertility.

Mistletoe is used pharmacologically to treat a variety of conditions such as high blood pressure and recent evidence suggest that at low doses extracts stimulate the immune systems whereas high doses have been used in the treatment of malignant tumours. I hasten to add that self-medication is not to be recommended but kissing underneath it should be safe enough!

 George Fussey FRSB FLS FZS

Curator

The Thames is the environmental lifeblood of Windsor and Eton and its wellbeing is unquestionably vital for the local balance of nature.  It is good to remind ourselves that the ecology of the River Thames has not always been healthy or stable.  In 1960s the Thames became so polluted that few fish species could survive and angling became a distant memory.  The recovery of the river to its current healthy state is a real success story that we can all be proud of.

But pollution is not the only factor that affects planetary biodiversity and puts species in jeopardy.  We are all aware of how illegal trade across international borders has been responsible for bringing species like the White Rhino to the very brink of extinction.  But who would have thought that a once familiar fish, which goes by the scientific name of Anguilla, would be affected by the same factor?

Photo of European Eel courtesy of GerardM – http://www.digischool.nl/bi/onderwaterbiologie/, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=284678

The European Eel, once a staple of the Cockney diet (‘Pie and Mash’), is an amazing species.  It undertakes one of the longest migrations in the animal kingdom.   After hatching in the Sargasso Sea (just south of Bermuda), Anguilla travels over to Europe.  As tiny ‘glass eels’ (the name given to the silvery juvenile elvers) they migrate up European rivers, making the difficult switch from a marine environment to a freshwater one.  Then, after several years in rivers like the Thames during which they can grow up to 1.5m long, the eels migrate back to the Sargasso Sea to spawn and complete their life cycle.

Two factors have led to the Zoological Society of London declaring the European Eel as a flagship species for nature conservation, following in the footsteps of iconic species like the Giant Panda.  The first is that modern rivers now have increasing numbers of barriers to migrating fish.  These can take the form of weirs and hydropower turbines.

The second factor which has placed the Eel on the so-called ‘red list’ of critically endangered species is the trade in the juvenile eels which arrive in our estuaries.  This is despite an international trade ban.  Eels are highly valued in east Asian cuisine and many eel species have declined markedly in recent years.  A kilogram of glass eels (numbering about 5,000 elvers) can fetch thousands of pounds.  The Japanese reportedly eat 100,000 tons of Unagi, or eels, every year!

 George Fussey FRSB FLS FZS

Curator