Horse Chestnut

views updated May 23 2018

Horse chestnut

Description

The European horse chestnut, Aesculus hippocastanum, is the horse chestnut most frequently used in herbal medicine. It is a member of the Hippocastanaceae family. Horse chestnuts are in an entirely different botanical family from the well-known sweet chestnut tree, Castanea vesca. Horse chestnuts exist in nature as both a tree and a shrub, and are found in all temperate regions of Europe, Asia, and North America.

There are 15 recognized species of horse chestnut. The European horse chestnut is believed to have originated in the Balkan region of eastern Europe but is now grown in every country in the Northern Hemisphere.

The name Aesculus is actually a misnomer, coming originally from the word esca, meaning food. It was applied by ancient peoples to a certain species of oak; somehow the name was transferred over the years to the horse chestnut. The name hippocastanum is thought to refer to the horse chestnut's ability to heal horses and cattle of respiratory illnesses. Another possibility may be that it is named for the small horseshoe-like markings that are present on the branches of the horse chestnut tree.

Horse chestnut trees grow in nearly any soil but seem to prefer a sandy loam. They grow very rapidly into tall straight trees that can reach heights of over 100 ft (approximately 30 m) tall, with widely spreading branches. The bark is grayish-green or grayish-brown in color, and the tree limbs are thick and have corky, elongated, wart-like eruptions that appear from a distance like ribbing. The interior of horse chestnut bark is pinkish-brown, with fine lines running its length. It is odorless and its taste is very bitter and astringent.

The characteristic horseshoe markings found on the branches are actually the scars from where leaves previously grew. Horse chestnut wood is seldom if ever used for lumber due to its soft and spongy character. Large leaf and flower buds are clearly visible even during winter months but are encased in a scaly, resinous protective covering that prevents damage from frost or damp. This thick sticky coating melts with the beginning of warm weather in spring, and flowers and leaves appear with remarkable rapidity, usually within three to four weeks.

The leaves are dark green, rough in texture, and large, with minutely serrated edges. Horse chestnut leaves can be nearly 1 ft (0.3 m) in length. They somewhat resemble a hand with five to nine leaf sections emerging from a palm-like base to form the finger-like projections. European horse chestnuts produce clusters of white flowers with a pale scarlet tinge at the throat or yellow mottling. American horse chestnut flowers can be white, pale pink, or yellow, depending upon the species. All types of horse chestnut trees, with their graceful wide limbs and showy flowers, are grown for their ornamental beauty.

The fruit of the horse chestnut is a dark brown smooth-surfaced nut approximately 2 in (5 cm) in diameter. It has a polished appearance except for the rounded dull tan-colored scar on the side that was attached to the seed vessel. Horse chestnuts are encased in a light green spine-covered coating that divides into three parts and drops away prior to the nut dropping from the tree. Horse chestnut nuts contain mostly carbohydrates which are generally indigestible until boiled. They also contain saponins, tannin, flavones, two glycosides, aesculin and fraxin, some crude protein, a fatty oil, ash and water.

Horse chestnuts native to North America are called buckeyes because of their large seeds which resembling the eye of a buck, or male deer.

American horse chestnuts are divided into four types:

  • Ohio buckeye, or Aesculus glabra, is a medium-sized tree which grows from the southern United States to the prairies of western Canada. It is the state tree of Ohio, hence the state's nickname of the Buckeye State.
  • Yellow buckeye, Aesculus octandra, or Aesculus flava, is a tree which grows to heights of 40 ft (12 m) or more. It is fairly common across the central portion of the United States. Its leaves are somewhat smoother than those of other horse chestnuts.
  • Red buckeye, or Aesculus pavia, is a shrub or small tree that generally is found in the southern United States. In early summer it develops brilliantly scarlet flowers in large clusters, and has dense foliage. The tree species of red buckeye grows to heights of between 1520 ft (57 m) tall.
  • California buckeye, or Aesculus californica, is a horse chestnut tree found all along the Pacific coast.

General use

Horse chestnuts have been used as fodder for feeding farm animals, and some Native American peoples have included them in their diet. However, the outer covering of the horse chestnut nut is toxic, and the nut itself has to be boiled prior to being eaten safely. Its wood, which is too soft for furniture-making or construction, is used in building crates and other packing cases.

Both the bark and the fruit from horse chestnut trees are used medicinally to strengthen and tone the circulatory system, especially the venous system. It is used both internally and externally to treat varicose veins, phlebitis , and hemorrhoids. Horse chestnut preparations are particularly effective in treating varicose ulcers. Due to its ability to improve circulation, it is also helpful for the relief of leg cramps. Its bark also has narcotic and fever-reducing properties. A compound known as aescin, which is present in the horse chestnut fruit, is now often added to external creams and preparations used for the treatment of varicose veins , varicose ulcers, bruises, and sports injuries.

Horse chestnut preparations using the seed, bark, twigs, and leaves are all utilized in traditional Chinese medicine. Chinese herbalists consider horse chestnut to be a part of treatment not only for circulatory problems, but use it as an astringent, as a diuretic, for reduction of edema or swelling, to reduce inflammation, as an expectorant in respiratory problems, and to fight viruses.

Preparations

Horse chestnut bark is removed in the spring in strips 4 or 5 in (1013 cm) long, about 1 in (2.5 cm) thick and broad. The fruit of the horse chestnut is gathered in the autumn, when they fall from the tree. Both the bark and the fruit are dried in sunlight or with artificial heat, and are either kept whole or ground to a powder for storage. A decoction made of 1 or 2 tsp of the dried, pulverized bark or fruit left to simmer for 15 minutes in 1 cup of water can be either taken internally three times a day or used externally as a lotion. Horse chestnut preparations are also available as tinctures, extracts, capsules, and external ointments and lotions.

Precautions

The outer husks of the horse chestnut fruit are poisonous. There are also reported cases of poisoning from eating raw horse chestnuts.

Side effects

There have been reported cases of gastrointestinal irritation, nausea , and vomiting from taking large doses of horse chestnut. There are also rare reports of rash and itching , and even rarer cases of kidney problems.

Interactions

Horse chestnut's ability to reduce blood coagulation, or clotting, indicates that it should not be given to those with bleeding disorders or who are taking anticoagulant drugs. It is known to add to the action of such blood thinning drugs as warfarin or aspirin.

Resources

BOOKS

Grieve, M., and C.F. Leyel. A Modern Herbal: The Medical, Culinary, Cosmetic and Economic Properties, Cultivation and Folklore of Herbs, Grasses, Fungi, Shrubs and Trees With All of Their Modern Scientific Uses. NY: Barnes and Noble Publishing, 1992.

Hoffman, David, and Linda Quayle. The Complete Illustrated Herbal: A Safe and Practical Guide to Making and Using Herbal Remedies. NY: Barnes and Noble Publishing, 1999.

Taber, Clarence Wilbur. Taber's Cyclopedic Medical Dictionary. Philadelphia: F. A. Davis Co., 1997.

OTHER

Hobbs, Christopher. "Herbal Advisor."http://www2.allherb.com/. Healing People. http//www.healingpeople.com. Support@healing people.com.

Joan Schonbeck

Horse Chestnut

views updated May 23 2018

Horse Chestnut

The horse chestnut and buckeyes (Aesculus spp.) are various species of angiosperm trees in the family Hippocastaneae. There are about 20 species of trees and shrubs in this family, occurring widely in temperate, angiosperm forests of Europe, Asia, and North America.

The horse chestnut and buckeyes have seasonally deciduous, oppositely arranged, palmately compound leaves, which means that the five to seven leaflets all originate from the same place at the far end of the petiole. The margins of the leaflets are coarsely toothed. The horse chestnut and buckeyes have attractive, whitish flowers, occurring in showy clusters. The flowers of Aesculus species develop in the springtime from the large, overwintering, sticky stem-bud, before the years leaves have grown. The flowers produce large quantities of nectar, and are insect pollinated. The fruits of the horse-chestnut and buckeyes are greenish, leathery, spiny capsules containing one or two large, attractive, chestnut-brown seeds. These seeds are not edible by humans.

The horse chestnut (Aesculus hippocastanum ) is a tree that can grow as tall as about 115 feet (35 m), and is native to Asia and southeastern Europe. The horse chestnut has been widely planted in North America as an ornamental tree, especially in cities and other residential areas. This species sometimes escapes from cultivation and becomes locally invasive, displacing native species from woodlands.

Several species of buckeyes are native to North America. Most species occur in hardwood forests of the eastern and central United States. The yellow buckeye (A. octandra) grows as tall as 98 feet (30 m) and can attain a diameter of almost 3.3 feet (1 m). The Ohio buckeye (A. glabra) and Texas buckeye (A. arguta) develop a characteristic, unpleasant odor when the leaves or twigs are crushed. The painted buckeye (A. sylvatica) and red buckeye (A. pavia) are relatively southeastern in distribution. The California buckeye (A. californica) is a shrub or small tree of drier foothill areas of the west coast of the United States.

These various native species are of relatively minor economic importance for their wood, which has been used to manufacture boxes, furniture, musical instruments, and other products.

The fruits of the horse chestnut and buckeyes are eaten by various species of wild animals and some species of livestock. However, these fruits contain a chemical known as aesculin that is poisonous to

humans if eaten in large quantities, and can cause death. The seeds of horse chestnut and buckeyes should not be confused with those of the true chestnuts (Castanea spp.), which are edible. (True chestnuts or sweet chestnuts are classified in the beech family, the Fagaceae.) However, it is reported that boiling or roasting the seeds of horse chestnut and buckeyes can remove or disable the aesculin to provide a starchy food.

Some people attribute medicinal qualities to the fruits and flowers of the horse chestnut and buckeyes. In Appalachia, some believe that buckeyes will help prevent rheumatism if carried on the person. Various preparations of the seeds, flowers, and bark have also been used as folk medicines to treat hemorrhoids, ulcers, rheumatism, neuralgia, and fever, and as a general tonic.

Sometimes children collect the horse chestnuts or buckeyes, drill a holes through the middles, and tie them to a strong string. The game of conkers involves contests in which these tethered seeds are swung at each other in turn, until one of the seeds breaks. Each time one conker defeats another it is said to gain a life. However, there are many variations of the rules of this game.

Bill Freedman

Horse Chestnut

views updated May 14 2018

Horse chestnut

The horse chestnut and buckeyes (Aesculus spp.) are various species of angiosperm trees in the family Hippocastaneae. There are about 20 species of trees and shrubs in this family, occurring widely in temperate, angiosperm forests of Europe , Asia , and North America .

The horse chestnut and buckeyes have seasonally deciduous, oppositely arranged, palmately compound leaves, which means that the five to seven leaflets all originate from the same place at the far end of the petiole. The margins of the leaflets are coarsely toothed. The horse chestnut and buckeyes have attractive, whitish flowers, occurring in showy clusters. The flowers of Aesculus species develop in the springtime from the large, over-wintering, sticky stem-bud, before the years' leaves have grown. The flowers produce large quantities of nectar , and are insect pollinated. The fruits of the horse-chestnut and buckeyes are greenish, leathery, spiny capsules containing one or two large, attractive, chestnut-brown seeds . These seeds are not edible by humans.

The horse chestnut (Aesculus hippocastanum) is a tree that can grow as tall as about 115 ft (35 m), and is native to Asia and southeastern Europe. The horse chestnut has been widely planted in North America as an ornamental tree, especially in cities and other residential areas. This species sometimes escapes from cultivation and becomes locally invasive, displacing native species from woodlands.

Several species of buckeyes are native to North America. Most species occur in hardwood forests of the eastern and central United States. The yellow buckeye (A. octandra) grows as tall as 98 ft (30 m) and can attain a diameter of almost 3.3 ft (1 m). The Ohio buckeye (A. glabra) and Texas buckeye (A. arguta) develop a characteristic, unpleasant odor when the leaves or twigs are crushed. The painted buckeye (A. sylvatica) and red buckeye (A. pavia) are relatively southeastern in distribution. The California buckeye (A. californica) is a shrub or small tree of drier foothill areas of the west coast of the United States.

These various, native species are of relatively minor economic importance for their wood , which has been used to manufacture boxes, furniture, musical instruments, and other products.

The fruits of the horse chestnut and buckeyes are eaten by various species of wild animals and some species of livestock . However, these fruits contain a chemical known as aesculin that is poisonous to humans if eaten in large quantities, and can cause death. The seeds of horse chestnut and buckeyes should not be confused with those of the true chestnuts (Castanea spp.), which are edible. (True chestnuts or sweet chestnuts are classified in the beech family, the Fagaceae.) However, it is reported that boiling or roasting the seeds of horse chestnut and buckeyes can remove or disable the aesculin, to provide a starchy food.

Some people attribute medicinal qualities to the fruits and flowers of the horse chestnut and buckeyes. In Appalachia, it is believed by some people that the seeds of buckeyes will help to prevent rheumatism, if carried around in your pockets. Various preparations of the seeds, flowers, and bark have also been used as folk medicines to treat hemorrhoids, ulcers , rheumatism, neuralgia, and fever, and as a general tonic.

Sometimes, children will collect the seeds of horse chestnut or buckeyes, drill a hole through the middle, and tie them to a strong string. The game of "conkers" involves contests in which these tethered seeds are swung at each other in turn, until one of the horse chestnuts breaks. Each time a particular conker defeats another, it is said to gain a "life." However, there are many variations of the rules of this game.

Bill Freedman

horse chestnut

views updated Jun 11 2018

horse chest·nut • n. a deciduous tree (genus Aesculus, family Hippocastanaceae) with large leaves of five leaflets, conspicuous sticky winter buds, and upright conical clusters of white, pink, or red flowers. Unrelated to true chestnuts, the horse chestnut bears unpalatable nuts enclosed in fleshy, thorny husks. ∎ the fruit or seed of this tree.

horse chestnut

views updated May 17 2018

horse chestnut Any of 25 species of deciduous trees that grow in temperate regions, especially the common horse chestnut, Aesculus hippocastanum. It has large leaves, long flower spikes, and round prickly fruits containing one or two inedible nuts. Family Hippocastanaceae. Height: to 30m (100ft).