Horse Chestnut Tree
Aesculus hippocastanum, the horse chestnut, is a species of flowering plant in the soapberry and lychee family Sapindaceae. It is a large deciduous, synoecious (hermaphroditic-flowered) tree. It is also called horse-chestnut, European horsechestnut, buckeye, and conker tree. It is sometimes called Spanish chestnut. This name is typically used for Castanea sativa.
It is a large tree, growing to about 39 metres (128 ft) tall with a domed crown of stout branches; on old trees the outer branches are often pendulous with curled-up tips. The leaves are opposite and palmately compound, with 5–7 leaflets; each leaflet is 13–30 cm (5–12 in) long, making the whole leaf up to 60 cm (24 in) across, with a 7–20 cm (3–8 in) petiole.
The leaf scars left on twigs after the leaves have fallen have a distinctive horseshoe shape, complete with seven “nails”. The flowers are usually white with a yellow to pink blotch at the base of the petals; they are produced in spring in erect panicles 10–30 cm (4–12 in) tall with about 20–50 flowers on each panicle. Its pollens are not poisonous for honey bees. Usually only 1–5 fruits develop on each panicle; the shell is a green, spiky capsule containing one (rarely two or three) nut-like seeds called conkers or horse-chestnuts.
Each conker is 2–4 cm (3⁄4–1 1⁄2 in) in diameter, glossy nut-brown with a whitish scar at the base
In Britain and Ireland, the seeds are used for the popular children’s game conkers. During the First World War, there was a campaign to ask for everyone (including children) to collect the seeds and donate them to the government.
The conkers were used as a source of starch for fermentation using the Clostridium acetobutylicum method devised by Chaim Weizmann to produce acetone for use as a solvent for the production of cordite, which was then used in military armaments. Weizmann’s process could use any source of starch, but the government chose to ask for conkers to avoid causing starvation by depleting food sources.
But conkers were found to be a poor source, and the factory only produced acetone for three months; however, they were collected again in the Second World War for the same reason.