The chestnut that horses don't want

Species name: Aesculus hippocastanum

Common name: horse chestnut

Location: Western University campus

The horse chestnut is a tree native to southern Europe around the Mediterranean and the Balkan Mountains. While the native range of this species is actually quite small, it is one of the dominant species that exists there and is also widely planted around the world. It can be a pretty nasty species (more on that below), but has a stunning flower display in late April and early May. The fruits, looking very similar to the fruits of the Ohio buckeye (which you can read all about HERE), start to appear in late summer. They are mostly left alone, but can be eaten (and seem to be enjoyed) by deer.

The common name of this plant is incredibly misleading, but is based in history. First the "horse" part refers to an anecdotal story that after horses ate the fruit, they would no longer complain of chest pain. You'd have to be some sort of pretty awesome horse-whisperer to be able to have a horse tell you it no longer had chest pain! The other minor detail to this story...you wouldn't be able to hear the horse telling you "Thanks! My chest pain is gone!" over the sounds of its seizures. Horse chestnut seeds and the fruit walls are poisonous to horses and should never be fed to them under any circumstances. Horses are pretty smart animals; they won't touch them. The other half of the name comes from the fact that it was believed that this tree was closely related to the American chestnut tree, mostly due to the fact that they have similar fruit and seed appearances. The leaves, however, are wildly different and the flowers of the true chestnut trees are also not nearly as showy. They are not easily confused, nor are they closely related! The true chestnuts and the horse chestnut are only distantly related.

The uses of the horse chestnut are so varied it makes me wonder if this really is a "miracle tree". The first use I'm just going to do the ultimate "thou shalt not do" and just copy-paste from the horse chestnut Wikipedia article because it's so mind-boggling. Here it is:
"In the past, horse-chestnut seeds were used in France and Switzerland for whitening hemp, flax, silk and wool. They contain a soapy juice, fit for washing of linens and stuffs, for milling of caps and stockings, etc., and for fulling of cloth. For this, 20 horse-chestnut seeds were sufficient for six litres of water. They were peeled then rasped, or dried and ground in a malt or other mill. The water must be soft, either rain or river water; hard well water will not work. The nuts are then steeped in cold water, which soon becomes frothy, as with soap, and then turns milky white. The liquid must be stirred well at first, and then, after standing to settle, strained or poured off clear. Linen washed in this liquid, and afterwards rinsed in clear running water, takes on an agreeable light sky-blue colour. It takes spots out of both linen and wool, and never damages or injures the cloth."
That is...crazy. How is this not marketed as a product?! A "natural" way to clean wool and linen, and the fibres are not destroyed in the process. The only thing I can figure is that it must be prepared fresh each time, and so it's viable today as a marketable product. If it was, it could be turned into a "Tide Stick type of product"--a Wool Stick?--and sold as a spot cleaner. This could be quite the money-maker...

The second historical use of the plant is as a soap and shampoo, along the same lines as the first use. The seeds are ground into boiling water in a sealable container (which sounds like a disaster waiting to happen, but what do I know?!), shaken vigorously (try not to have the container explode on you...), and then strained. Once the liquid is cool enough to be applied to the scalp, it works to remove the buildup from your hair. Nifty! Not nifty enough for me personally to want to try it, but nifty all the same.

Along a totally different vein, the seeds of the horse chestnut can also be broken into small pieces and then added to a fermentation solution containing the bacterium Clostridium acetobutylicum, from the same genus of bacteria that gives us botulism which is a very potent type of food poisoning, which produces acetone as an end product of fermentation (instead of the usual ethanol like brewer's yeast produces). Acetone can then be diluted to make nail polish remover, or it could be used later in the production of cordite (it's first use, prior to nail polish remover), an explosive used in bombs (and as a gunpowder replacement in other explosive devices like bullets).

And yet another completely different use, in order for an outdoor patio to be called a true "beer garden," it must be shaded by horse chestnuts according to Bavarian law. Now the term applies to any outdoor patio space where beer is the main item consumed, but that didn't used to be the case. Bavarian law also dictates (as an aside) the only four ingredients which may be used in the beer-making process: water, barley, hops, and yeast. If the "beer" that you drink contains anything other than those four ingredients (such as wheat beers, rice beers, or beers flavoured with things other than hops), it technically cannot be called beer.

One of the compounds found in horse chestnut seed extract, aescin, is used medicinally to treat a condition called chronic venous insufficiency or CVI. This condition arises when the veins can no longer return deoxygenated blood in your body back to your heart (where it pumps it to your lungs to push out the carbon dioxide and pick up new oxygen). This can result in severe pain due to a lack of oxygen in the extremities, and in especially severe cases can result in the loss of limbs. The causes of this condition can be quite varied, with specific medical conditions often arising in CVI (like diabetes, MS, and even a brief disruption of oxygen to a developing embryo in the womb) or the result of repeated leg injuries (like in the case of paratroopers, tree-climbers, mountain climbers, or people who climb utility poles for repairs). This is not a do-it-yourself medical treatment, however. The aescin must be carefully extracted from the seeds and purified in order to exclude any esculin, a deadly toxic glycoside also present in horse chestnut seeds, from the preparation. If even a small amount of esculin is ingested it can result in seizure, vomiting, severe dehydration, coma, and even death. Unfortunately, this doesn't stop homeopathic practitioners from prescribing it as a homeopathic remedy to thin the blood. Yet another example of the idea that just because it's natural doesn't mean it's good for you or even safe. Be aware of what you're putting in your body and the potential side effects!