SLOE: CHARACTERISTICS, HABITAT, HEALING PROPERTIES, CARE - BIOLOGY - 2025

The sloe (Prunus spinosa) is a deciduous plant belonging to the Rosaceae family. It is commonly known as blackthorn, sloe, black hawthorn, bruñera, border plum, briñón, gruño, arañón, aranyoner or aranyó, among others.

Black hawthorn is a bush-shaped species that normally reaches 2 m in height. It has short and spiny twigs, small alternate leaves, white flowers and its fruits look like plums covered by a white layer.

Prunus spinosa. Source: pixabay.com

It inhabits much of Europe, Asia, Africa and the United States. The height at which it grows is between 0 and 900 meters above sea level. It is associated with communities of rose bushes, hazelnuts, hawthorn, sanguinos, bonnets, privets, and is found in oak and holm oak groves.

This plant species is known for its healing properties, which allow its use as an antidiarrheal, laxative, antioxidant, anti-inflammatory, antitumor, diuretic, immunostimulator and vasodilator. However, its consumption in excess can be toxic. The seeds contain hydrocyanic acid, which is why they are considered poisonous.

Other uses given to sloe are to make canes, clubs, rakes and for turnery. In the same way, the fruits or sloes are in great demand for the preparation of jams and jellies. They are also used as a base for the preparation of a drink called pacharán.

characteristics

Plant

It is a deciduous plant with a bushy bearing that grows more or less between 1 and 2 m in height. Some individuals have reached up to 6 m in height. It has short, thorny and patent twigs, whose terminations are on a rigid spike.

Leaves, branches and fruits of the sloe. Source: pixabay.com

Leaves

The blackthorn has small alternate leaves, 1.5-3.5 cm long, with lanceolate or elliptical shape and serrated edges; they have pubescence on the petiole and on the underside. The petiole measures 1.5 cm.

flowers

The flowers can appear in groups (of two or three) or solitary, they are very abundant and precocious, their color is white. It has a cup formed by five sepals of 3 mm in diameter. The flowers are erect, resembling a pyramid and show a sharp apex.

Likewise, the inflorescence has five elongated and whitish petals measuring 4 to 8 mm; it also has numerous stamens.

Blackthorn inflorescence. Source: pixabay.com

Flowering coincides with the growth of new leaves, starting from the beginning of spring specifically from January to March and ending at most in May.

On the other hand, the pollination of this plant requires insects (entomophilous) and, in turn, is self-incompatible, which is why it needs pollen from other individuals.

Fruit

The fruit of this species is a globose drupe measuring between 10 and 15 mm in diameter. Its color is blue-blackish due to the amount of antioxidant pigments such as anthocyanins and carotenoids contained within.

The fruit is called sloe, it is covered with a whitish-looking film, it is edible and has a sour and bittersweet taste. The appearance of the fruit resembles that of a rounded plum.

The seed that is inside the fruit is covered and protected by the endocarp, is brown, rough and has a kind of lateral keel-shaped suture.

Fruiting takes place in summer and remains on the plant until December. Seed dispersal occurs by frugivorous vertebrates.

Taxonomy

-Kingdom: Plantae.

-Filo: Tracheophyta.

-Class: Magnoliosida.

-Subclass: Magnoliidae.

-Superorden: Rosanae.

-Order: Rosales.

-Family: Rosaceae.

-Gender: Prunus.

-Species: Prunus spinosa L. (1753).

This shrub is also known as the basionym Prunus domestica var. spinosa. It also has some synonyms such as Prunus moldavica and Prunus stepposa.

Blackthorn flower detail. Source: pixabay.com

Habitat and distribution

The blackthorn is distributed in a large part of the European territory, in Western Asia, the northern part of Africa and in the United States. It is also found in the Iberian Peninsula in its northern and central area, as well as in the Balearic Islands.

It is found at heights ranging from 0 to 900 meters above sea level, although it can reach 1500 meters above sea level. It grows in any type of soil, although it prefers those of a limestone or marl nature, and little is found in siliceous substrates. It can grow in direct sunlight or in semi-shady conditions.

It is a spiny species typical of the degradation or clearing of oak forests, wild pine forests, holm oaks and cork oaks. Its habitat is also around gall oaks, riparian forests, elm trees, and Juniperus thurifera junipers.

Thus, the blackthorn is associated with communities of rose bushes, hazelnut trees, hawthorns, sanguinos, bonnets, privets, etc.

Thorny branches of sloe. Source: pixabay.com

Healing properties

The blackthorn fruit provides very few calories to the body and its carbohydrate content is also low. In contrast, they have a high fiber content, which makes this plant useful for relieving constipation problems.

In this sense, blackthorn is widely used for its astringent effect that serves to stop diarrhea and relieve stomach inflammation. For this, the fruits are subjected to a decoction which the affected person can drink in the amount they want.

With regard to the treatment of hemorrhoids, it is recommended to wash with the decoction of the bark for about 10 minutes to relieve the inflammation of the rectum.

The flowers of this shrub are used for their laxative properties. To do this, simply prepare an infusion for at least eight minutes and swallow it.

Additionally, the infusion of its flowers for three minutes is useful to alleviate physiological and psychological disorders caused by menopause such as palpitations, hot flashes, depression, insomnia, etc.

The flowers are also useful for treating skin conditions such as acne or dermatosis. At this point, it is recommended to ingest a couple of cups daily of the flower decoction.

In addition, the fruit contains a significant amount of carotenoids and anthocyanins that prevent oxidation or the formation of free radicals.

Blackthorn flowers. Source: pixabay.com

Blackthorn chemical components

In the whole plant they contain acids such as caffeic and ferulic acid, which serve as diuretics, Vulneraries, anticancer agents, stimulators of the immune systems and vasodilators.

The fruit contains pectin and tannins, which are substances applied as antitumor, antidiarrheal and bactericidal.

The flower contains quercithin and rutin, substances that are used as antiulceric, antihemorrhoidal, anti-inflammatory, hypotensive, hypoglycemic, among others. In addition, in the flower is amygdalin, a substance that acts as cyanogenetic and toxic.

Now, the seeds contain hydrocyanic acid, so its intake is considered poisonous.

Other uses

In general, the herb or shrub Prunus spinosa has been used as a medicinal and edible plant. But, it is also very useful for making canes, clubs, rakes and for turnery.

Similarly, the blackthorn fruits are in great demand for the preparation of jams and jellies. They are also used as a fragrance for certain alcohols, particularly for the preparation of the drink called pacharán.

In the cosmetic field, they are used to prepare beauty masks.

Side effects

The consumption of sloe can cause certain counterproductive effects such as:

- Dermatitis: it is enough that the skin becomes irritated only with direct contact with any structure of the green plant (fruits, leaves, flowers).

- Allergy: it has been observed that some people who have an allergy to plants of the Rosaceae family can also develop an allergy to blackthorn.

- Stomach and belly pain: due to the amount of tannins contained in blackthorn, the gastric mucosa can become irritated and also affect the stomach. Therefore, it should not be abused in the consumption of its fruits.

Blackthorn fruits and branches. Source: pixabay.com

Care

This plant tolerates pruning and grafting; in turn, it sprouts easily from the root. Direct sunlight supports optimal blackthorn growth, but it can grow well in partial shade locations.

In case of late frosts, Prunus spinosa requires protection. For this, a good tying or securing of the plant must be carried out.

Maintenance under warm temperatures produces healthy fruits with excellent flavor.

As in other species, moderate watering is recommended to avoid waterlogging in the soil. Avoid growing on excess lime because it may show chlorosis.

Its cultivation is recommended in pH between 4.5 and 7.5, as well as, the nitrogen concentration should be just in the lower limit for its development.

Its propagation is from seed during the spring, but it can also be propagated through grafting.

Its cultivation can be carried out in isolation or, in the case of its cultivation in the field, it can be sown aligned with other individuals of the same species to create a kind of barrier or fence that is difficult to penetrate.

During the harvest, great care must be taken with the bark of this shrub due to the substance it contains called prussic acid, which can be toxic and dangerous, especially for the production of sweets or liqueurs.

Spectacular blackthorn flowering in spring. Source: pixabay.com

Plagues and diseases

Although Prunus spinosa is highly resistant to pests and diseases, but it can be attacked by certain organisms such as:

- The red spider. that causes the change of color of the leaves towards a metallic appearance, and the subsequent fall of the leaves and the fruits.

- Rust disease, which causes defoliation and a decrease in the diameter of the trunk.

References

1. Fernández, M., Reyes, A. 2013. Prunus spinosa L. In: Production and management of seeds and forest plants. J. Pemán, RM Navarro, JL Nicolás, MA Prada, R. Serrada (eds). Autonomous Agency of National Parks. Ministry of Agriculture, Food and Environment. pp. 158-165.
2. Catalog of Life: 2019 Annual Checklist. Species details: Prunus spinosa L. Taken from: catalogueoflife.org
3. The Taxonomicon. (2004-2019). Taxon: Species Prunus spinosa Linnaeus. Taken from: taxonomicon.taxonomy.nl
4. Tropics 2019. Prunus spinosa L. Taken from: tropicos.org
5. Flowers. 2019. Prunus spinosa. Taken from: flores.ninja
6. Botanical-Online SL. (1999-2019). Blackthorn properties. botanical-online.com