When it rains conkers

In one of the most popular scenes in the BBC adaptation of Jane Austen’s Pride and Prejudice [1], Mr Darcy (Colin Firth) dived into the lake at Pemberley and then encountered Elizabeth Bennet (Jennifer Ehle) while walking back to the house. His swim was an invention, although the meeting at Pemberley does take place in the book, as does the introduction to Mr and Mrs Gardiner (Tim Wylton and Joanna David). In that dialogue, there is further invention when Mr Darcy relates that he used to run from Pemberley into Lambton (more than four miles!) as a boy to collect horse chestnuts from the tree on the green. It did seem an odd thing to do, but maybe there were no suitable horse chestnut trees on the Pemberley estate, despite its many acres of “some of the finest woods in the country” [1]?

The dialogue brought fond memories of playing conkers to all of us who watched the programme: collecting the conkers; making a hole through the “best” ones with a meat skewer; and threading through a piece of strong and knotting its end. Then heading for the playground to try and demolish someone else’s conker by swiping at it with one’s own prized weapon, while avoiding, as much as possible, sore knuckles from an opponent’s misguided shot. During these contests there was much chat of how to prepare the best conkers (with vinegar and baking), although the ones we used were not treated.

I was reminded of those times earlier this week as I walked across Boxmoor in Hertfordshire, that has a splendid avenue of horse chestnut (Aeschylus hippocastanum) trees (see above). It had been raining and there was a moderate breeze, with the result that conkers were falling constantly and I was grateful that my bald head was covered by a cloth cap (although none of them fell on me). There were conkers all over the path and the freshly-fallen ones had that lovely lustre of polished veneers that soon dies on exposure to the air. Each conker is different in shape and patterning and they are beautiful: they provide yet another aspect of the “mellow fruitfulness” of autumn and one which brings, for me, a child-like appreciation of the natural world.

Christian believers might suggest that this is something that God intended at the time of the Creation, but atheists are more likely to point to the evolution of the horse chestnut, that began many millions of years ago, way before the creatures that led to H. sapiens first appeared. Conkers are, of course the means of dispersal of future generations of trees and we probably all remember planting some in pots and watching shoots appear at the surface of the soil.

Earlier this year, an interesting paper on the horse chestnut appeared in the Journal of Ecology [2]. It is a comprehensive account, well worth reading for those who love these trees, and it includes the following information:

Aeschylus hippocastanum is native to the Balkan Peninsula in south-east Europe but has been widely planted in temperate areas from the 17th Century onwards..

..Horse chestnut is best known as a tree planted for ornamentation and shade in parks and streets, particularly by the Victorians, since little else can rival the sight of a horse-chestnut in full flower. Indeed, it was voted the UK’s favourite tree in 2017 in a poll run by the Royal Society of Biology. The British population is an estimated 470,000 trees.

Like many other trees, horse chestnuts are attacked by insects and by disease organisms [2]. Those having the greatest aesthetic impact are larvae of a leaf-mining moth, Cameraria ohridella, that first appeared in the late 1970s in Macedonia. They feed on the tissue inside the leaf and produce unsightly brown blotches that have the effect of colouring the whole tree through the summer months and into autumn. While these attacks reduce the ability of the tree to photosynthesise, and thus produce energy, the trees still produce conkers (if smaller and in lower numbers than in unaffected areas). It would be so sad if future generations were prevented from enjoying the appearance of these wonderful fruits, then gathering them for a game of conkers. Or is that the sentiment of an old man, out of touch with the modern age?

[1] Jane Austen (1813) Pride and Prejudice. London, T.Egerton.

[2] Peter A. Thomas, Omar Alhamd, Grzegorz Iszkulo, Monika Dering and Tarek A. Mukassabi (2019) Biological Flora of the British Isles: Aeschylus hippocastanum. Journal of Ecology 107:992-1030.