JUNIPER: CHARACTERISTICS, HABITAT, PROPERTIES, REPRODUCTION - BIOLOGY - 2025

The juniper (Juniperus communis) is an evergreen shrub or tree statured belonging to the family Cupressaceae. Known as ajarje, cypress, common juniper, gorbicio, jabino, jinbro, juniper or sabino it is a native species of the mountainous regions of Europe, Asia and North America.

It is a bush with very leafy branches that measures 2-4 meters, although under suitable conditions it can reach 10 m in height. It is characterized by its slow growth, smooth reddish-brown bark and needle-like leaves on whorls arranged in three-by-three spiral groups.

Juniper (Juniperus communis). Source: MPF

It is classified as a dioecious species, that is, there are plants differentiated as male or female. The male flowers are cylindrical, yellowish and located in a terminal position; the oval female ones are formed by fleshy blue-blackish scales.

The fruits are a fleshy berry known as galbulo, green in color at first, which turns blue or purple when ripe. In its interior the fertile scales that contain the seeds that take up to two years to mature are located.

Galbules are the most valued part of juniper due to its medicinal properties such as balsamic, expectorant and diuretic. In addition, they are consumed to eliminate free radicals from the body and stimulate the immune system due to the presence of antioxidants, polyphenols and flavonoids.

On the other hand, its use is not limited to the therapeutic plane, it is also used as an ornamental plant and the fruits are used in gastronomy. In the same way, its by-products are used at a cosmetic and industrial level and the fruits provide a particular flavor and aroma to the gin.

General characteristics

Appearance

Short tree or evergreen shrub with an erect or sloping growth that can reach 4 to 10 m in height. It is the only species of the genus Juniperus that has arboreal bearing, the other species barely reach one meter in height.

It is a highly branched shrub, with open, cylindrical and erect branches, sometimes in an ascending position. The fibrous bark is brown in color and easily exfoliated in longitudinal strips. It also has smooth twigs of 5-10 mm in diameter.

Leaves

The acicular, short and sharp leaves 10-20 cm long, are arranged in a spiral three by three in whorls on the branches. They are grayish-green or bluish-green on the underside and have a single pale band on the upper side. They are densely grouped on the branches.

flowers

Juniper is a dioecious shrub, that is, the plants are separated into female and male members, thus the flowers are of one or the other gender. Usually, flowering occurs in the spring and fruiting in the fall.

The male flowers are grouped in small yellow cones, are located in a terminal position and are responsible for producing pollen. The female flowers are axillary, globular, and light green to bluish-black in color, with small fleshy scales.

Fruit

Male juniper flowers (Juniperus communis). Source: Shkumbin on Flickr

The fruit is a fleshy indehiscent berry or gall, resinous, lignified and green in color that turns bluish-black when ripe. It measures 6 to 10 mm in diameter. Inside there are 2 to 3 oval seeds 4-5 mm long, which mature at 18-24 months.

Composition

The Juniperus communis species is not only used as an ornamental plant, but due to its high content of bioactive elements, it is used as a medicinal plant.

Among the main elements of therapeutic action are acetic, ascorbic, chlorogenic and torulosic acids in the fruits. While in wood the terpenes a-pinene, a-copaene, a-phelandrene, a-humulene, a-terpinene, b-phelandrene, b-pinene, ga-terpineol, eucalyptol, furruginol, nerol and sabinene.

In addition, the essential oil terpinen-4-ol is found in the fruits and leaves and the terpenoid camphor and menthol are found in the fruits.

Wood contains high levels of tannins, resins, and certain hydrolyzable tannins such as gallotannins. The fruits also contain resins and tannins, in addition to juniperin, the carbohydrates glucose and fructose, as well as the natural fiber pectin.

The fruits have a high nutritional value, since they have vitamins B ₁, B ₃ and C, calcium, chromium, cobalt, phosphorus, iron, magnesium, manganese, selenium, sodium, potassium and zinc. In the same way, they have the flavonoids apigenin, catechin, epicatechin, epigallocatechin and gallocatechin.

Taxonomy

- Kingdom: Plantae

- Division: Pinophyta

- Class: Pinopsida

- Order: Pinales

- Family: Cupressaceae

- Genus: Juniperus

- Section: Junipers

- Species: Juniperus communis L., 1753.

Etymology

Juniper fruits (Juniperus communis). Source: Isidre blanc

- Juniperus: the genus name comes from the Latin «iuniperus», which designates the name of «juniper».

- communis: the specific adjective derives from the Latin word meaning "common or vulgar."

Subspecies and varieties

Due to its extensive geographical distribution, various subspecies and varieties have developed:

- Juniperus communis subsp. communis: erect shrub or low-growing tree with leaves 5-20 cm long. It is located in areas of low or medium altitude, in temperate climates. It is the characteristic species of juniper.

- Juniperus communis subsp. communis var. communis: it is located in Europe and northern Asia.

- Juniperus communis subsp. communis var. depressa: common of North America.

- Juniperus communis subsp. communis var. hemisphaerica: high mountains of the Mediterranean basin.

- Juniperus communis subsp. communis var. nipponica: it is located in Japan.

- Juniperus communis subsp. alpina: known as the dwarf juniper, it is a creeping shrub with 3-8 cm long leaves. It is located in subarctic and alpine regions at high altitude.

- Juniperus communis subsp. alpina var. alpine: it is located in Greenland, Europe and Asia.

- Juniperus communis subsp. alpina var. megistocarpa: exclusive to eastern Canada, similar to the alpine variety.

- Juniperus communis subsp. alpina var. jackii: it is located in the western United States.

- Juniperus communis subsp. nana: known as creeping juniper, jabino, jabina, nebrina, sabina or zaina. It is a plump shrub with drooping stems 10-60 cm tall with short leaves. It is located in the north-central region of the Iberian Peninsula.

Synonymy

Juniper leaves (Juniperus communis). Source: Isidre blanc

- Juniperus albanica Pénzes

- Juniperus argaea Balansa ex Parl

- Juniperus borealis Salisb

- Juniperus caucasica Fisch. ex Gordon

- Juniperus compressa Carrière

- Juniperus Krakow K. Koch

- Juniperus dealbata Loudon

- Juniperus depressa Stevels

- Juniperus difformis Gilib.

- Juniperus echinoformis Rinz ex Bolse

- Juniperus elliptica K. Koch

- Juniperus fastigiata Knight

- Juniperus hemisphaerica C. Presl

- Juniperus hibernica Lodd. ex Loudon

- Juniperus hispanica Booth ex Endl

- Juniperus interrupta HL Wendl. ex Endl

- Juniperus kanitzii Csató

- Juniperus microphylla Antoine

- Juniperus niemannii EL Wolf

- Juniperus oblonga-pendula (Loudon) Van Geert ex K. Koch

- Juniperus oblongopendula Loudon ex Beissn

- Juniperus occidentalis Carrière

- Juniperus oxycedrus subsp. hemisphaerica (J. Presl & C. Presl) E. Schmid

- Juniperus reflects Gordon

- Juniperus saxatilis Lindl. & Gordon

- Juniperus suecica Mill

- Juniperus taurica Lindl. & Gordon

- Juniperus uralensis Beissn

- Juniperus vulgaris Bubani

- Juniperus withmanniana Carrière

- Sabina dealbata (Loudon) Antoine

- Thuiaecarpus juniperinus Trautv

Habitat and distribution

The Juniperus communis species thrives in areas of extreme temperature, whether in cold or hot environments. In addition, it withstands the strong winds characteristic of mountain systems or high peaks.

It grows on any type of soil, even low fertility and stony soils, although it prefers soils of calcareous origin. Regarding its water requirements, it adapts to loose soils with a loamy-sandy texture, with good drainage as it is susceptible to waterlogging.

Juniper is an evergreen shrub found in the wild in the mountainous regions of Europe, South Asia, and North America. In the Iberian Peninsula, the Juniperus communis species is the most common of the central, eastern and northern regions.

Properties

The main use of juniper is as an ornamental plant and, with its wood, small utensils, artisan figures, boxes or containers are made. The fruits are used to make a special type of gin and as a medicinal for the therapeutic treatment of various disorders.

Medicinal properties

Juniper plant in full fruiting. Source: Chris Cant from Cumbria, UK

Juniper fruits or galbules contain various active principles that give it certain medicinal properties. It is used to treat certain discomforts of the urinary system, muscular, gastrointestinal and joint problems.

The essential oils present not only in the fruits, but also in branches and leaves, are used as a diuretic. Likewise, they are used to improve the functioning of the urinary system, including the bladder and kidneys, as well as for the elimination of gases.

The aroma of the plant is used to relieve headaches or symptoms of bronchitis when inhaling the vapors of its cooking. The ingestion of infusions of branches or fruits stimulates the production of gastric juices, soothing stomach inflammation or gastrointestinal disorders.

In the same way, it calms heartburn, bloating, gastric infections, loss of appetite and acts as a dewormer. In addition, it allows cleaning the urinary tract, being indicated to eliminate excess fluid in the body, heal urethritis, kidney stones and bladder.

Its ingestion as tea or infusion regulates glucose levels in the blood, controls pain during menstruation and protects the pancreas. Topically applied to the skin to alleviate injuries or inflammation, soothe the burning sensation caused by heat stroke, insect bites or certain types of dermatitis.

Other uses

- Ornamental: its most frequent use is as an ornamental plant in squares, parks and gardens, since its low size limits its timber use.

- Logger: the wood is of very good quality due to its fine and closed texture. It is very resistant to humidity, it is used to make kitchen utensils, tool handles or craft figures. The wood is used to smoke cheeses and sausages.

- Food: The fruits are used in the manufacture of condiments or spices to season meat, fish and poultry. In addition, they are used as raw material for the distillation of gin.

- Cosmetology: it constitutes raw material for the manufacture of lip paint, compact powder, perfumes, soap, gels, creams and shampoos.

- Industrial: a high quality varnish is obtained from the resin obtained from juniper which through a drying process becomes a blotter used in stationery.

- Decoration: in certain areas of Europe, juniper branches are a symbol of Christmas to decorate houses on Christmas Eve and New Year.

Reproduction

Seeds

The seeds are collected from ripe fruits or gallbules. For their use they require a stratification process, initially with sulfuric acid for 30 minutes and 4 months at less than 6 ºC in the refrigerator.

Another option is to sow the seeds without stratification during the summer, however, it is a slow process and the germination percentage is reduced. Juniper is a slow-growing plant, it takes more than two years to transplant the seedlings or use them as a pattern for grafting.

Cuttings

Juniper seedling (Juniperus communis). Source: Krzysztof Ziarnek, Kenraiz

The selection of the 15-20 cm long cuttings is carried out during the winter of healthy and vigorous plants. It is recommended to apply rooting hormones, insert into a peat and perlite-based substrate, and place under nursery conditions protected from direct light.

To achieve rooting as quickly as possible, it is recommended to keep the ambient humidity high and provide background heat. Indeed, it is recommended to spray the cuttings frequently and cover the area with transparent plastic that maintains the interior temperature.

Graft

Juniper in the wild. Source: Øyvind Holmstad

The grafting is carried out during the autumn on seedlings obtained through seeds, which have a straight stem and firm development. The seedlings are planted in pots with a fertile substrate and placed in a greenhouse or under a structure with transparent plastic.

After 15-20 days, the branches to be grafted are selected from a strong and vigorous mother plant, without signs of pests or diseases. It is recommended to apply the lateral graft technique, where the cut is made from the side, the branch is inserted and it is held with tape for grafts or rubber bands.

The pots are covered with black peat until the graft area and are placed in a greenhouse under partial shade, at a temperature of 24 ºC and 85% relative humidity. After 5-8 weeks the graft has healed and the plant is taken outside trying to eliminate the upper part of the pattern.

Care

Juniper is an easy shrub to grow, widely used as an ornamental plant, being planted as a dwarf conifer in parks and gardens. However, it requires special care such as the right amount of light, soil pH and soil moisture.

Location

For its effective development, the plant must be located in full sun exposure, although it develops well in semi-shade. It is a plant that adapts to various environmental conditions, it is tolerant of occasional frosts, extreme heat and strong winds.

Floor

It grows on soils of calcareous origin with a slightly acidic, neutral or very alkaline pH. It prefers soils with a sandy, loamy or clayey texture and adapts to low fertility soils.

Irrigation

It is a very resistant species to drought, so it requires moderate watering throughout the year. However, it is susceptible to flooded land, so it must be watered taking into account environmental conditions and that the soil is dry.

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It is recommended to apply some type of organic compost or compost during the spring and fall. The application of chemical fertilizers is indicated based on the chemical analysis of the land and that the plantation is carried out commercially.

Transplant

It is not very tolerant to the transplanting process, the ideal is to transplant to a larger pot for adaptation before sowing in the final site. Both sowing and transplantation should be carried out during spring or autumn, avoiding the risks of frost.

Pruning

Juniper tolerates pruning very well, both maintenance and training, however, it is advisable to maintain its natural shape. It is advisable to trim the branches that have grown irregularly, carry out a formation pruning to turn it into a hedge or cultivate as bonsai.

Plagues and diseases

Juniper (Juniperus communis) is a hardy, rustic arboreal plant that can survive harsh environmental conditions and extreme climates. However, under certain conditions it can be affected by different pests or diseases that drastically reduce its performance, even causing death.

Pests

Cottony mealybug (Planococcus citri) and spider mite (Tetranychus urticae) are common, sucking sap from stems, branches and leaves. Mealybugs produce malformations in stems and leaves, spider mites cause wilting of shoots and leaves.

Mealybugs are effectively controlled with special oils such as paraffin oil, in severe cases the application of chlorpyrifos or imidacloprid is recommended. To control the spider mite, neem oil can be applied or the plant washed with potassium soap, if the plague persists, an miticide can be used.

Diseases

Under conditions of poor soil drainage and flooding, the root system of the plant can be attacked by phytopathogenic fungi such as Fusarium or Phytophthora. The highest incidence of this type of disease occurs during the spring, when humid and hot climates occur.

References

1. Bueso Zaera, JA (2013) The Juniper (Juniperus communis L.) Botany. Ontejas - Cultural Association of Fortanete.
2. Junipers (2018) Ornamental Plants. Recovered in: plantsornamentales.org
3. Juniperus (2019). Wikipedia, The Free Encyclopedia. Recovered at: es.wikipedia.org
4. Juniperus communis (2019) Wikipedia, The Free Encyclopedia. Recovered at: es.wikipedia.org
5. Juniperus communis L. (2019) Species details. Catalog of Life: 2019 Annual Checklist. Recovered at: catalogueoflife.org
6. Juniperus communis - JB-96-04 (2019) Botanical Garden of the University of Malaga. Recovered at: jardinbotanico.uma.es
7. Vidigal Gómez, A. (2017). Pharmacological Aspects and Toxicology of Juniperus communis (Doctoral dissertation) Faculty of Pharmacy. Complutense University. 20 pp.