Common Horse-chestnut
Encyclopedia
Aesculus hippocastanum is a large deciduous
tree
, commonly known as Horse-chestnut or Conker tree.
s of the Balkans
in southeast Europe
, in small areas in northern Greece
, Albania
, the Republic of Macedonia
, Serbia
, and Bulgaria
(Pindus Mountains mixed forests
and Balkan mixed forests
). It is widely cultivated throughout the temperate world.
It grows to 36 m tall, with a domed crown of stout branches, on old trees the outer branches often pendulous with curled-up tips. The leaves
are opposite and palmately compound, with 5–7 leaflets; each leaflet is 13–30 cm long, making the whole leaf up to 60 cm across, with a 7–20 cm petiole. The leaf scars left on twigs after the leaves have fallen have a distinctive horseshoe
shape, complete with seven "nails". The flower
s are usually white with a small red spot; they are produced in spring in erect panicles 10–30 cm tall with about 20–50 flowers on each panicle. Usually only 1–5 fruit
develop on each panicle; the shell is a green, softly spiky capsule
containing one (rarely two or three) nut
-like seed
s called conkers or horse-chestnuts. Each conker is 2–4 cm diameter, glossy nut-brown with a whitish scar at the base.
, together with the observation that eating them cured horses of chest complaints despite this plant being poisonous to horses.
Cultivation for its spectacular spring flowers is successful in a range of climatic conditions provided summers are not too hot, with trees being grown as far north as Edmonton, Alberta
, the Faroe Islands
, and Harstad
, Norway
. In more southern areas, growth is best in cooler mountain climates.
In Britain
and Ireland
, the nuts are used for the popular children's game conkers. During the two world wars, horse-chestnuts were used as a source of starch
which in turn could be used via the Clostridium acetobutylicum
fermentation method devised by Chaim Weizmann
to produce acetone
. This acetone was then used as a solvent which aided in the process of ballistite
extrusion into cordite
, which was then used in military armaments.
The nuts, especially those that are young and fresh, are slightly poisonous, containing alkaloid
saponin
s and glucoside
s. Although not dangerous to touch, they cause sickness when eaten; consumed by horses, they can cause tremors and lack of coordination.. Some mammal
s, notably deer
, are able to break down the toxins and eat them safely.
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 liters 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.
In Bavaria
the chestnut is the typical tree for a beer garden
. Originally they were planted for their deep shade which meant that beer cellar owners could cut ice from local rivers and lakes in winter to cool the Märzen Lager
beer well into summer. Nowadays guests enjoy the shade to keep their heads cool - even after the second Maß
(a mug with a liter of beer).
Conkers have been threatened by the leaf-mining moth Cameraria ohridella, whose larvae feed on horse chestnut leaves. The moth was described from Macedonia where the species was discovered in 1984 but took 18 years to reach Britain.
Aesculus hippocastanum is used in Bach flower remedies
. When the buds are used it is referred to as "Chestnut Bud" and when the flowers are used it is referred to as "White Chestnut".
The flower is the symbol of the city of Kiev
, capital of Ukraine
.
Horse-chestnuts can be used to make jewelry using the conkers as beads.
Although the horse-chestnut is sometimes known as the buckeye, this name is generally reserved for the New World
members of the Aesculus
genus.
A famous specimen was the Anne Frank Tree
, a horse-chestnut in the center of Amsterdam
which she mentioned in her diary and which survived there until August 2010.
Deciduous
Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...
tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
, commonly known as Horse-chestnut or Conker tree.
Distribution
Aesculus hippocastanum is native to a small area in the mountainMountain
Image:Himalaya_annotated.jpg|thumb|right|The Himalayan mountain range with Mount Everestrect 58 14 160 49 Chomo Lonzorect 200 28 335 52 Makalurect 378 24 566 45 Mount Everestrect 188 581 920 656 Tibetan Plateaurect 250 406 340 427 Rong River...
s of the Balkans
Balkans
The Balkans is a geopolitical and cultural region of southeastern Europe...
in southeast Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, in small areas in northern Greece
Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....
, Albania
Albania
Albania , officially known as the Republic of Albania , is a country in Southeastern Europe, in the Balkans region. It is bordered by Montenegro to the northwest, Kosovo to the northeast, the Republic of Macedonia to the east and Greece to the south and southeast. It has a coast on the Adriatic Sea...
, the Republic of Macedonia
Republic of Macedonia
Macedonia , officially the Republic of Macedonia , is a country located in the central Balkan peninsula in Southeast Europe. It is one of the successor states of the former Yugoslavia, from which it declared independence in 1991...
, Serbia
Serbia
Serbia , officially the Republic of Serbia , is a landlocked country located at the crossroads of Central and Southeast Europe, covering the southern part of the Carpathian basin and the central part of the Balkans...
, and Bulgaria
Bulgaria
Bulgaria , officially the Republic of Bulgaria , is a parliamentary democracy within a unitary constitutional republic in Southeast Europe. The country borders Romania to the north, Serbia and Macedonia to the west, Greece and Turkey to the south, as well as the Black Sea to the east...
(Pindus Mountains mixed forests
Pindus Mountains mixed forests
The Pindus Mountains mixed forests constitute a terrestrial ecoregion of Europe according to both the WWF and Digital Map of European Ecological Regions by the European Environment Agency...
and Balkan mixed forests
Balkan mixed forests
The Balkan mixed forests constitute a terrestrial ecoregion of Europe according to both the WWF and Digital Map of European Ecological Regions by the European Environment Agency...
). It is widely cultivated throughout the temperate world.
Growth
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are opposite and palmately compound, with 5–7 leaflets; each leaflet is 13–30 cm long, making the whole leaf up to 60 cm across, with a 7–20 cm petiole. The leaf scars left on twigs after the leaves have fallen have a distinctive horseshoe
Horseshoe
A horseshoe, is a fabricated product, normally made of metal, although sometimes made partially or wholly of modern synthetic materials, designed to protect a horse's hoof from wear and tear. Shoes are attached on the palmar surface of the hooves, usually nailed through the insensitive hoof wall...
shape, complete with seven "nails". The flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s are usually white with a small red spot; they are produced in spring in erect panicles 10–30 cm tall with about 20–50 flowers on each panicle. Usually only 1–5 fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
develop on each panicle; the shell is a green, softly spiky capsule
Capsule (fruit)
In botany a capsule is a type of simple, dry fruit produced by many species of flowering plants. A capsule is a structure composed of two or more carpels that in most cases is dehiscent, i.e. at maturity, it splits apart to release the seeds within. A few capsules are indehiscent, for example...
containing one (rarely two or three) nut
Nut (fruit)
A nut is a hard-shelled fruit of some plants having an indehiscent seed. While a wide variety of dried seeds and fruits are called nuts in English, only a certain number of them are considered by biologists to be true nuts...
-like seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s called conkers or horse-chestnuts. Each conker is 2–4 cm diameter, glossy nut-brown with a whitish scar at the base.
Etymology
The common name horse-chestnut is reported as having originated from the erroneous belief that the tree was a kind of chestnutChestnut
Chestnut , some species called chinkapin or chinquapin, is a genus of eight or nine species of deciduous trees and shrubs in the beech family Fagaceae, native to temperate regions of the Northern Hemisphere. The name also refers to the edible nuts they produce.-Species:The chestnut belongs to the...
, together with the observation that eating them cured horses of chest complaints despite this plant being poisonous to horses.
Uses
Alberta
Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...
, the Faroe Islands
Faroe Islands
The Faroe Islands are an island group situated between the Norwegian Sea and the North Atlantic Ocean, approximately halfway between Scotland and Iceland. The Faroe Islands are a self-governing territory within the Kingdom of Denmark, along with Denmark proper and Greenland...
, and Harstad
Harstad
is the second largest city and municipality by population, in Troms county, Norway – the city is also the third largest in North Norway. Thus Harstad is the natural centre for its district. Situated approximately north of the Arctic Circle, the city celebrated its 100th anniversary in...
, Norway
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
. In more southern areas, growth is best in cooler mountain climates.
In Britain
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
and Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
, the nuts are used for the popular children's game conkers. During the two world wars, horse-chestnuts were used as a source of starch
Starch
Starch or amylum is a carbohydrate consisting of a large number of glucose units joined together by glycosidic bonds. This polysaccharide is produced by all green plants as an energy store...
which in turn could be used via the Clostridium acetobutylicum
Clostridium acetobutylicum
Clostridium acetobutylicum, ATCC 824, is included in the genus Clostridium, is a commercially valuable bacterium sometimes called the "Weizmann Organism", after Jewish-Russian born Chaim Weizmann, then senior lecturer at the University of Manchester, England, used them in 1916 as a bio-chemical...
fermentation method devised by Chaim Weizmann
Chaim Weizmann
Chaim Azriel Weizmann, , was a Zionist leader, President of the Zionist Organization, and the first President of the State of Israel. He was elected on 1 February 1949, and served until his death in 1952....
to produce acetone
Acetone
Acetone is the organic compound with the formula 2CO, a colorless, mobile, flammable liquid, the simplest example of the ketones.Acetone is miscible with water and serves as an important solvent in its own right, typically as the solvent of choice for cleaning purposes in the laboratory...
. This acetone was then used as a solvent which aided in the process of ballistite
Ballistite
Ballistite is a smokeless propellant made from two high explosives, nitrocellulose and nitroglycerine. It was developed and patented by Alfred Nobel in the late 19th century.-The development of smokeless powders:...
extrusion into cordite
Cordite
Cordite is a family of smokeless propellants developed and produced in the United Kingdom from 1889 to replace gunpowder as a military propellant. Like gunpowder, cordite is classified as a low explosive because of its slow burning rates and consequently low brisance...
, which was then used in military armaments.
The nuts, especially those that are young and fresh, are slightly poisonous, containing alkaloid
Alkaloid
Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids...
saponin
Saponin
Saponins are a class of chemical compounds, one of many secondary metabolites found in natural sources, with saponins found in particular abundance in various plant species...
s and glucoside
Glucoside
A glucoside is a glycoside that is derived from glucose. Glucosides are common in plants, but rare in animals. Glucose is produced when a glucoside is hydrolysed by purely chemical means, or decomposed by fermentation or enzymes....
s. Although not dangerous to touch, they cause sickness when eaten; consumed by horses, they can cause tremors and lack of coordination.. Some mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s, notably deer
Deer
Deer are the ruminant mammals forming the family Cervidae. Species in the Cervidae family include white-tailed deer, elk, moose, red deer, reindeer, fallow deer, roe deer and chital. Male deer of all species and female reindeer grow and shed new antlers each year...
, are able to break down the toxins and eat them safely.
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
and Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
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 liters 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.
In Bavaria
Bavaria
Bavaria, formally the Free State of Bavaria is a state of Germany, located in the southeast of Germany. With an area of , it is the largest state by area, forming almost 20% of the total land area of Germany...
the chestnut is the typical tree for a beer garden
Beer garden
Beer garden is an open-air area where beer, other drinks and local food are served. The concept originates from and is most common in Southern Germany...
. Originally they were planted for their deep shade which meant that beer cellar owners could cut ice from local rivers and lakes in winter to cool the Märzen Lager
Lager
Lager is a type of beer made from malted barley that is brewed and stored at low temperatures. There are many types of lager; pale lager is the most widely-consumed and commercially available style of beer in the world; Pilsner, Bock, Dortmunder Export and Märzen are all styles of lager...
beer well into summer. Nowadays guests enjoy the shade to keep their heads cool - even after the second Maß
Maß
The is a term used in German-speaking countries for a unit of volume, now typically used only for measuring beer sold for immediate on-site consumption. In modern times, a is defined as exactly 1 litre....
(a mug with a liter of beer).
Conkers have been threatened by the leaf-mining moth Cameraria ohridella, whose larvae feed on horse chestnut leaves. The moth was described from Macedonia where the species was discovered in 1984 but took 18 years to reach Britain.
Aesculus hippocastanum is used in Bach flower remedies
Bach flower remedies
Bach flower remedies are dilutions of flower material developed by Edward Bach, an English bacteriologist, pathologist and homeopath, in the 1930s. Bach believed that dew found on flower petals retain healing properties of that plant...
. When the buds are used it is referred to as "Chestnut Bud" and when the flowers are used it is referred to as "White Chestnut".
The flower is the symbol of the city of Kiev
Kiev
Kiev or Kyiv is the capital and the largest city of Ukraine, located in the north central part of the country on the Dnieper River. The population as of the 2001 census was 2,611,300. However, higher numbers have been cited in the press....
, capital of Ukraine
Ukraine
Ukraine is a country in Eastern Europe. It has an area of 603,628 km², making it the second largest contiguous country on the European continent, after Russia...
.
New World
The New World is one of the names used for the Western Hemisphere, specifically America and sometimes Oceania . The term originated in the late 15th century, when America had been recently discovered by European explorers, expanding the geographical horizon of the people of the European middle...
members of the Aesculus
Aesculus
The genus Aesculus comprises 13-19 species of woody trees and shrubs native to the temperate northern hemisphere, with 6 species native to North America and 7-13 species native to Eurasia; there are also several hybrids. Species are deciduous or evergreen...
genus.
A famous specimen was the Anne Frank Tree
Anne Frank tree
The Anne Frank tree was a horse-chestnut tree in the city center of Amsterdam that was featured in Anne Frank's The Diary of a Young Girl. Anne Frank described the tree from The Annexe, the building where she and her family were hiding from the Nazis during World War II...
, a horse-chestnut in the center of Amsterdam
Amsterdam
Amsterdam is the largest city and the capital of the Netherlands. The current position of Amsterdam as capital city of the Kingdom of the Netherlands is governed by the constitution of August 24, 1815 and its successors. Amsterdam has a population of 783,364 within city limits, an urban population...
which she mentioned in her diary and which survived there until August 2010.
Bonsai
The Conker has many fans in the Bonsai World, and especially in Europe, where they make lovely large bonsai, though there are also known to make smaller Bonsai too.Diseases
- Bleeding CankerBleeding Canker of Horse ChestnutBleeding Canker of Horse Chestnut is a common canker of horse chestnut trees that is known to be caused by infection with several different pathogens....
. Half of all Horse-chestnuts in Great Britain are now showing symptoms to some degree of this potentially lethal bacterial infection. - Guignardia leaf blotch, caused by the fungus Guignardia aesculi
- Wood rotting fungi, e.g. such as Armillaria and GanodermaGanodermaGanoderma is a genus of polypore mushrooms which grow on wood and include about 80 species, many from tropical regions. Because of their extensive use in traditional Asian medicines, and their potential in bioremediation, they are a very important genus economically. Ganoderma can be differentiated...
- Horse-chestnut scale, caused by the insect Pulvinaria regalis
- Horse-chestnut leaf miner, Cameraria ohridella, a leaf mining moth.
- Phytophthora bleeding canker, a fungal infection.