GORSE: CHARACTERISTICS, TAXONOMY, HABITAT, PROPERTIES, CARE - BIOLOGY - 2025

The gorse (Ulex europaeus) is a shrub native to Western Europe belonging to the family Fabaceae. It is commonly known as gorse, gatosa, argoma, espinillo, prickly broom, ulaga, abulaga, gorse, jabulaga, rozo, carqueja or sea buckthorn, among others.

It is a shrub of about 2.5 m in height, with a stem that can be creeping or erect and that has a strong branching. It does not present leaves as they have been modified into quite sharp spines. Instead, it develops lanceolate or triangular phyllodes.

Flowers and branch of Ulex europaeus. Source: pixabay.com

The flowers of this shrub are quite striking yellow. Its fruit is a legume that contains 2 to 8 seeds. It is a shrub whose reproduction can be sexual or asexual. It is a pioneer and highly invasive species. However, due to these characteristics, it can be used for ecosystem restoration plans.

Its characteristics such as high reproduction, fast growth, dormant seeds, long vegetative period, lack of controlling agents, have made gorse a strong pest for agricultural and forestry areas in various parts of the world. It can be controlled by a specific moth (Agonopterix ulicetella) that feeds on its shoots, thus reducing its establishment and reproduction.

Regarding its care, it requires direct exposure to the sun for its adequate growth, watering between 2 and 3 times a week, pruning whenever dry or necrotic branches appear. It is normally propagated by seeds in spring.

It is used as firewood or for charcoal production, its flowers are useful for natural dessert decorations, the plants are established as living fences, and its wood is useful for light carpentry. As for its medicinal properties, it is used to combat headaches and as a cardiotonic.

characteristics

Plant

Gorse is a shrub that is up to 2.5 m high, the stem can be creeping or erect, with abundant semi-open or compact branches.

Detail of gorse thorns. Source: pixabay.com

The young branches are dark green in color, covered by long trichomes and their appearance is obvious. It forms spines up to about 4 cm long, they can be straight or arched.

Leaves

The leaves in this plant are replaced by primary phyllodes that measure between 5 and 12 mm, with a lanceolate-linear or triangular shape, devoid of pubescence or with some trichomes. It has 2-6 mm by 2-7.5 mm bracteoles. Pedicels are pubescent.

flowers

The flowers are yellowish-yellow. They are located in the armpits of the phyllodes or needles. The calyx measures 11 to 16 mm, has thick and patent-looking trichomes. The upper lip is between 5 and 6 mm wide; the corolla shows a banner and wings longer than the calyx.

It has 10 stamens, of different sizes, united by their filaments. The ovary is seated, with the arched style and its stigma in a terminal position.

Ulex europaeus. Source: pixabay.com

Flowering occurs from November to May or June. If this species is found in cool climate areas, it can have flowers throughout the year.

Fruit

The fruit is a legume that measures between 10 and 20 mm long by 5-7 mm wide, ovate or oblong and contains 2 to 8 seeds.

Seeds

Gorse seeds are ovoid, compressed on their sides, more or less asymmetrical, green, brown or black in color once they mature, they measure approximately 2.5 mm, they show a smooth texture and a shiny appearance.

The seed coat is characterized by being hard, waterproof and dormant. This allows the seeds to have a high probability of survival in adverse conditions such as fire or other disturbances for a long time (up to 30 years).

Taxonomy

-Kingdom: Plantae

-Filo: Tracheophyta

-Class: Magnoliopsida

-Order: Fabales

-Family: Fabaceae

-Gender: Ulex

-Species: Ulex europaeus

Some synonyms for this species are: Ulex armoricanus, Ulex compositus, European Ulex, Ulex floridus, Ulex hibernicus, Ulex major, Ulex opistholepis, Ulex strictus, Ulex vernalis.

Gorse flower. Source: pixabay.com

Habitat and distribution

Gorse is obtained associated with heaths, hedges, communities of thorny vegetation. It is normally found in bushes, moors and forest clearings. It grows between 0 and 1300 meters above sea level. It grows well on soils with a lot of silica and close to the ocean.

It is native to southwestern Europe and has been mobilized to North and South America, South Africa, and Australia. It lives in places such as Argentina, Ecuador, Uruguay, the United States, Jamaica, Costa Rica, Chile, China, Colombia, Madagascar, Canada, Bolivia, Indonesia, Portugal or Spain, among others.

Properties

Gorse contains an interesting alkaloid substance, cytisine, with which problems of asthma, whooping cough and headaches have been fought. It also contains two other alkaloids such as caulophyllin and anagirin.

Cytisine is an alkaloid that serves to replace nicotine and has been used as a patch for smokers who want to quit smoking. The results have been more effective than those obtained with nicotine patches.

Likewise, it is considered that the flowers can have as healthy effects as that of boldo leaves to treat liver conditions.

Toxicity

The alkaloid cytisine can be very poisonous. The concentration in the seeds is close to 1%, and this part of the plant should not be used for consumption or preparation of infusions.

Even its use as forage is questionable due to the presence of this poisonous substance not only in seeds but also in branches or other organs.

Ecological aspects

Favorably, since it is a fabaceous plant, its lateral roots are nodulated by rhizobial bacteria which fix atmospheric nitrogen. Once contributed to the plant, it remains available in the soil once the nodule, the structure of the plant (root) is degraded, or it is diffused to the soil through the flow of substances in the rhizosphere.

Applications

- In some regions of the world gorse is grown for forage. For this, their branches are crushed, their thorns removed, and beds are made for cattle.

- In traditional medicine the flowers are used as an infusion to treat liver problems.

- The trunk serves very well as firewood or for the production of charcoal.

- On the other hand, because it is a fabaceous plant, it serves as a green manure by providing nitrogen to the soil.

- It is also cultivated as an ornamental species, and to be used as a living fence.

- Its flowers are used as natural decorations for desserts or other special foods.

- It is used a lot for the production of honey because it contributes enough pollen to bees.

Ulex europaeus seen against the light. Source: pixabay.com

Care

Light

Light conditions are of utmost importance for gorse, as it allows it to develop properly. The lower branches that do not receive sun dry out quickly, they remain attached to the plant and this causes an accumulation of organic matter that burns easily; for this reason, it is a harmful plant.

Irrigation

It should be watered between 2 and 3 times each week during the summer season, and at other times the frequency of watering can decrease. It is important that the substrate has good drainage to avoid waterlogging.

Fertilization

Organic compost can be applied during the spring and summer season.

Pruning

Due to the susceptibility of branches to burn easily, pruning is recommended whenever dry, weak branches or those with some evidence of disease are observed.

Temperature

Regarding the temperature, this shrub supports frosts to an extreme of -10 ° C.

Spread

Gorse normally multiplies by seed during the spring. The seeds require scarification to germinate.

Scarification with sandpaper can produce up to 73% germination. Otherwise, germination can be increased above 90% if the testa is removed with a scalpel.

The ideal temperature at which gorse germinates is between 15 and 19 ° C. Whereas, above 35 ° C the seed becomes unviable.

Shrub of Ulex europaeus. Source: pixabay.com

Biologic control

Gorse can be biologically controlled by the defoliator moth Agonopterix ulicetella, which is an insect that attacks this plant with considerable specificity. In general, it affects its growth as it consumes its tender shoots.

The adult individuals of the moth lay their eggs on the thorns and stems of gorse in spring. After a month, the emerging larvae head towards the new shoots and feed on them. For this, the larvae produce and are kept in a silk channel within the growth shoots and spines.

References

1. Norambuena, H., Escobar, S., Rodríguez, F. 2001. Biological control of Ulex europaeus L.: admission to Chile of two populations of the bioagent Agonopterix ulicetella (Stainton) (Lepidoptera: Oecophoridae). Technical Agriculture 61 (1): 82-88.
2. Ocampo-Zuleta, K., Solorza-Bejarano, J. 2017. Seed bank of spiny broom Ulex europaeus L. on the edges of the invasive scrub in a zonal ecosystem of high Andean forest, Colombia. Colombian Biota 18 (1): 89-98.
3. Amaya-Villareal, A., Renjifo, LM 2010. Effect of spiny broom (Ulex europaeus) on edge birds in a high Andean forest. Colombian Ornithology 10: 11-25.
4. Vascular Flora. 2019. Ulex europaeus L. Taken from: floravascular.com
5. López González, G. 2004. Genus Ulex L. In: Guide to the trees and shrubs of the Iberian Peninsula and the Balearic Islands. Editions Mundi-Prensa. 2nd ed. p 404-405. Taken from: books.google.co.ve
6. Catalog of Life: Annual Checklist. 2019. Species details: Ulex europaeus L. Taken from: catalogueoflife.org
7. Duhart, K. 2012. Study of the alkaloid composition of Ulex europaeus L. (Fabaceae) in Chile and its biological activity. Master of Science Degree Work, Botanical mention. University of Concepción. Chile. 72 p. Taken from: repositorio.udec.cl
8. López, D. 2014. Toxo or Tojo, Ulex europaeus. Taken from: plantersoffices.com
9. Sánchez, M. 2019. Toxo plant (Ulex europaeus). Taken from: jardineriaon.com