CASTANEA SATIVA: CHARACTERISTICS, HABITAT, CULTIVATION, USES - BIOLOGY - 2025

The Castanea sativa, or brown, is a deciduous tree large plant belonging to the family Fagaceae. Native to Asia Minor and the Middle East, it is today a cosmopolitan plant widely found in temperate climates.

It is cultivated mainly to obtain the fruit, known as chestnut, which represents an important source of food in various European regions. The chestnut tree is a mesophilic species, which develops effectively in environmental conditions of non-extreme humidity and temperature.

Chestnut (Castanea sativa). Source: fir0002 flagstaffotos gmail.com Canon 20D + Tamron 28-75mm f / 2.8

It is a deciduous tree with an oval and irregular crown that reaches 20-35 m in height and a crown width of 15-20 m. When adult, it has a dark brown split bark, sometimes hollowed out, with numerous thick longitudinal branches.

It has large lanceolate leaves, leathery and serrated, of bright green color and up to 20 cm in length. Flowering occurs during the months of May-June, the male and female flowers grow together and are yellowish when ripe.

The fruit is an achene covered by a green spiny dome or hedgehog, inside which are located 2-7 chestnuts. Ripening occurs gradually in the months of September-November, it is an edible product and constitutes a food of high nutritional value.

Indeed, chestnuts contain up to 40% carbohydrates, being a very energetic food. In addition, it has vitamins A, B and C, proteins, fats and mineral salts.

On the other hand, it contains various active components such as tannins and pectins that provide it with medicinal properties. In fact, it has astringent properties useful in case of diarrhea and conditions in the mouth or throat. Likewise, it is antitussive, relieves cough and irritation in the pharynx.

General characteristics

Appearance

It is an arboreal species that reaches 25-35 m in height, with a short, straight, thick stem and widely branched from the base. The bark is smooth, grayish or brownish in color when young, then becomes rough and fissured reddish-brown when adult.

In young plants the crown is conical and open, and as it grows it becomes columnar, wide and rounded. The short, erect and thick branches are arranged in whorls establishing multiple strata of branches.

Foliage

The simple leaves, 10-30 cm long, are oblong-lanceolate, rough, coriaceous and deciduous, and are arranged alternately on short petioles. The apex is generally pointed and the base is heart-shaped with prominent veins on the underside and serrated margins.

The upper surface is glabrous and glossy dark green, the underside slightly pubescent and pale green. In early fall, glossy green leaves turn dull orange.

flowers

The chestnut is a monoecious species that blooms between May-June on the Mediterranean coast and from June-July in the north of the Iberian Peninsula. Usually, the flowering of yellow and gold tones is very exuberant, giving the tree a very showy appearance.

The male flowers are grouped discontinuously in yellow catkins 20 cm long. These catkins are arranged with 5-10 glomeruli at short intervals at the ends of the branches.

The female ones are grouped in axillary glomeruli at the base of the male inflorescences. When ripe, they are covered by a green coating of soft thorns that, when opened, leave 2-7 fruits or chestnuts free.

Flowering chestnut (Castanea sativa). Source: Naoneisig

Fruit

The fruit is a 2-4 cm globular achene, covered by an involucre with long spines that are initially green and yellowish when ripe. This structure, called hedgehog, when maturing opens by dehiscence into 2-4 valves, leaving free the chestnuts located inside.

The white, soft and smooth inner layer of the involucre contains the edible brown chestnuts and hemispherical shape. Chestnuts 2-3 cm in diameter have a firm, shiny pericarp with a terminal ridge-shaped scar.

Chemical composition

Chestnuts have a high content of vitamin C (12%), as well as high levels of vitamin B6, folic acid and thiamine. Comparatively, it has a higher content of moisture and carbohydrates than other nuts, although its content of organic oils is lower (1%).

The protein content is relatively low (5-7%) but it is of very good quality, being easily absorbed during the digestive process. In addition, it has a considerable amount of copper, potassium and magnesium, low in sodium and lacks elements that alter cholesterol levels.

Taxonomy

- Kingdom: Plantae

- Division: Magnoliophyta

- Class: Magnoliopsida

- Order: Fagales

- Family: Fagaceae

- Subfamily: Quercoideae

- Genus: Castanea

- Species: Castanea sativa Mill., Gard. Dict., Ed. 8., n. 1, 1768

Etymology

- Castanea: the genus name comes from the Greek «χάστανον» and the Latin «castănĕa, -ae» which means chestnut or chestnut. It also refers to the chestnut nut called "castaneanux".

- sativa: the specific adjective derives from the Latin word meaning "cultivated."

Leaves and fruits of the chestnut (Castanea sativa). Source: Frank Vincentz

Synonymy

- Castanea castanea (L.) H. Karst.

- Castanea prolifera (K. Koch) Hickel

- C. sativa f. discolor Vuk.

- C. sativa var. hamulata A. Camus

- Castanea sativa var. Lavialle microcarpa

- Castanea sativa var. prolifera K. Koch

- C. sativa var. spicata Husn.

- C. vesca Gaertn.

- Castanea vulgaris Lam.

- Fagus castanea L.

- Fagus castanea var. Weston variegata

- F. procera Salisb.

Varieties

The varieties most cultivated commercially are the so-called "browns", which produce larger chestnuts with a striated and light bark. The episperm or seminal covering of the seed does not penetrate the pulp, being easier to peel.

Generally, cultivated varieties, such as browns, contain only one or two chestnuts per hedgehog. While wild varieties can produce three or more chestnuts for each hedgehog.

Ripe fruit with chestnuts (Castanea sativa). Source: Fir0002

Habitat and distribution

Castanea sativa is a species native to Asia Minor, which was introduced throughout Europe by the Greeks and Romans. In the Iberian Peninsula, in addition to Spain, it is located in the north and center of Portugal, in France it is located in the central massif and Corsica.

In Italy it is distributed throughout the peninsula, including Sardinia and Sicily, also to the southeast of England and the region of the Rhine Valley in Germany. On the other hand, it is located in Austria, Hungary, Romania, Serbia, Greece and south of Moravia and Slovakia.

It is a species that forms extensive forests alone or in association with other tree species on loamy and humid soils. It prefers soils of siliceous origin to the detriment of calcareous soils.

Its natural habitat is characterized by regular or abundant rainfall, without drought in the land during the summer months. As well as deep, well drained, slightly acidic soils, loamy texture, high content of organic matter and without accumulation of mineral salts.

Culture

The chestnut is a species that multiplies through seeds, which require physical separation from the external dome. In fact, these seeds are recalcitrant and can be stored only for a short time in humid environments and at low temperatures.

For its cultivation in the nursery the seeds of this species do not require a previous pregerminative treatment. Only use fresh and viable seed, or collected the previous fall and stored under adequate humidity and low temperature conditions.

Chestnut trunk (Castanea sativa). Source: Dieter Simon Dieter simon

The sowing is done in 400 cc polyethylene bags on a porous, fertile substrate, with constant humidity and under semi-shade. Maintaining the appropriate management conditions, seedlings are obtained that at 20-60 cm in height will be ready for transplanting.

Likewise, the technique of vegetative reproduction by layering can be used. In this case, the generation of roots is induced on a branch not separated from the mother plant, later it is separated and transplanted to the definitive place.

Care

The chestnut is grown in areas with a temperate climate and a humid environment, with a mild winter with occasional frosts above 10 ºC. It grows on loose and fertile soils, with a deep clay-loam texture, slightly acidic pH (5 to 6.5) and with good drainage.

Waterlogged soils due to overwatering can cause root rot and eventually plant death. Also, warm and hot environments tend to drastically reduce the production of female flowers, and therefore the decrease in fruiting.

Centennial chestnut in flowering. Source: pixabay.com

Its cultivation is restricted in regions with a subtropical climate and coastal areas, since the production and quality of chestnuts decreases. This species requires an average of 450-650 cold hours to maintain its flowering levels, temperatures below 0 ºC can cause its death.

It is susceptible to summer droughts and strong winter frosts, as well as cold spring and occasional frosts in the fall. On the other hand, in humid forest ecosystems it adapts to shady conditions, and grows on mountainous slopes whenever the summers are cool.

In addition, its optimal development and production is subject to an adequate supply of moisture and nutritional contributions to the land. In this regard, it is recommended to apply a fertilizer with a high content of nitrogen, potassium and magnesium during the spring and summer.

Adverse conditions are conducive to the appearance of two pests of economic interest, such as canker and ink. However, the great vitality of this species and its ability to regrowth has ensured its survival in different regions.

Diseases

Chestnut ink (

Oomycete phytopathogenic fungus responsible for the disease called "chestnut ink", especially in plants that grow in humid areas. Symptoms manifest as blackening of the root system and the presence of dark spots along the trunk.

The affected area produces a thick black discharge similar to ink. The infected plant tends to weaken rapidly, leading to death when infections are severe.

Chestnut chancre (

Ascomycete fungus that causes a serious necrotic disease that is transmitted through contaminated tools when pruning is carried out. The fungus penetrates through wounds caused by physical damage, pruning or grafting, even through wounds caused by other pathogens.

The affected area initially presents a mold that later becomes necrotic and spreads around it causing it to dry out. Many times the affected tissues grow and widen taking the form of a chancre, in severe cases the plant can dry out.

Chestnut canker (Cryphonectria parasitica). Source: Pennsylvania Department of Conservation and Natural Resources - Forestry

Applications

Nutritional

It is cultivated mainly to obtain chestnuts that are consumed raw or processed, and they are also widely used in confectionery. Indeed, it is considered a food with excellent energy content, and its nutritional composition is as healthy as cereals.

It contains various carbohydrates that favor the body's sugar levels, and also allow to reduce the feeling of hunger. Its high fiber content contributes to intestinal activity, and because it lacks gluten it is recommended for celiacs.

It is an ideal food for children, due to its contribution of calcium and potassium, essential for the proper development of bones and muscles. It is also recommended for athletes, its potassium content prevents muscle tears and is a product with a high energy intake.

Since ancient times, the chestnut has been known as the «breadfruit», since a flour used in pastry making is obtained from chestnuts. They are a fundamental part of the Spanish diet, being used in the preparation of various traditional dishes, such as Galician broth and Asturian pot.

The leaves are used fresh as a food supplement for livestock. Likewise, chestnuts constitute a food source for various wild species, such as squirrels, deer, wild boar and wild birds, among others.

Chestnuts Source: Wildfeuer

Industrial

The wood of the chestnut tree is used for the manufacture of handmade furniture, elaboration of pieces in cabinetmaking, as well as tutors, barrels, fences or ropes. The wood is uniformly light in color and has a strong grain that is easy to roll, turn, drill, brush and polish.

The products made with this wood are very resistant to wear and tear, being suitable for making frames, doors, windows and floors. The bark contains various tannins that are used in the tannery industry for the treatment and dyeing of hides.

Medicinal

The leaves and bark of the chestnut have a high content of tannins that gives it antiseptic and astringent properties. Indeed, an infusion made from leaves or bark is an effective remedy to alleviate the symptoms caused by infectious diarrhea.

With the leaves and bark you can prepare a macerate that is applied topically on wounds, injuries and irritations. This remedy helps to disinfect the wound, favors its healing and allows the skin to recover quickly.

The leaves contain a hamenoside component with expectorant, anti-inflammatory, antitussive and soothing properties, ideal for relieving cold disorders. In fact, it acts as an effective medicine to calm coughs, reduce inflammation of the bronchial tubes and provide an expectorant effect.

An oil rich in unsaturated fats is extracted from chestnuts, which help to reduce LDL cholesterol levels in the blood. This oil is also used in cosmetology, as it provides smoothness and firmness to the skin, as well as strength to the hair.

References

1. Castanea sativa. (2019). Wikipedia, The Free Encyclopedia. Recovered at: es.wikipedia.org
2. Castanea sativa Miller (2010) Wild Seeds. Plain trees and shrubs. Recovered in: semillassilvestres.com
3. Conedera, M., Tinner, W., Krebs, P., de Rigo, D., & Caudullo, G. (2016). Castanea sativa in Europe: distribution, habitat, usage and threats. European Atlas of Forest Tree Species. Publ. Off. EU, Luxembourg.
4. Fernández López, J. and Alía Miranda, R. (2008) Castanea sativa. Brown. Euforgen. Technical guide for the genetic conservation and use of the Chestnut (Castanea sativa). Madrid. Spain. 6 p. ISSN 1575-2356
5. Ferre, R. (2018) El Castaño, Tree of Expansion. Kyreo Center - Training Center for Alternative Therapies. Recovered at: kyreo.es
6. Molina, F., del Valle, F., Fernández de AnaMagán, F., & Molina, B. (2003). Guide to forestry, production of high value wood, walnut. Galicia, Spain: Galicia Forestry Association.
7. Oterino, AG (1982). On the introduction of Chestnut, Castanea sativa, in the Western Mediterranean. Zephyrvs, 34.
8. Venturini, G. (2018) Castanea sativa. Monaco Nature Encyclopedia. Recovered at: monaconatureencyclopedia.com