ATRIPLEX HALIMUS: CHARACTERISTICS, HABITAT, USES, DISEASES - BIOLOGY - 2024

Atriplex halimus is a species of compact forage shrub of medium size that belongs to the Chenopodiaceae family. Commonly known as armuella, marismo, orgaza, osagra, salted white, brackish, Andalusian salgado or soda, it is a native plant of the Mediterranean basin.

It is an evergreen shrub that is highly branched from the base, with wavy silvery-gray leaves that can reach 1 to 3 m in height. The small greenish-yellow flowers are arranged in panicles, while the fruit is an achene covered by two valves and the oval, whitish seeds.

Atriplex halimus. Source: Fabricio Cárdenas

It grows in arid, hot and dry environments, it is moderately frost tolerant and is characterized by its great resistance to soil salinity. It is located in coastal and sub-coastal regions on loamy, loamy or chalky soils, even sandy soils, reaching up to 1,000 meters above sea level.

It is used as a forage plant, for restoration of degraded lands, erosion control and prevention of forest fires. As an ornamental plant it is used to form hedges or form screens with other species in regions with a coastal climate.

General characteristics

Appearance

Shrubby evergreen plant that reaches up to 2.5-3 m in height, branched and tangled from the base. Woody stem, the outer branches arranged more horizontally than the inner ones, smooth or slightly cracked bark, grayish-green or ashy.

Highly branched pivoting root system that can penetrate up to 2-3 m deep. Under certain favorable ground conditions, it can even go up to 10 m deep.

Leaves

Polyiform leaves, from ovate or elliptical to lanceolate, whitish tones, whole and slightly wavy margins, with a short petiole and arranged alternately. Each leaflet reaches 4-5 cm in length, main veins evident on the underside, a somewhat succulent consistency and has numerous trichomes on both sides.

Leaves of Atriplex halimus. Source: Krzysztof Ziarnek, Kenraiz

flowers

Monoecious plant with anemophilic pollination, with unisexual yellow-green flowers, in some cases hermaphroditic flowers, grouped in terminal panicles. The male ones have 5 yellowish tepals and a whorl of stamens, while the female ones have two oval bracteoles that cover the carpel. Flowering occurs during the summer.

Fruit

The monosperm fruit is an ovoid achene protected by two valves and provided with a membranous wing of a pink-whitish hue. The fruit remains on the plant during spring and its dispersion is facilitated by wind, rain and the passage of animals. The rounded seeds are whitish in color.

Taxonomy

- Kingdom: Plantae

- Division: Magnoliophyta

- Class: Magnoliopsida

- Subclass: Caryophyllidae

- Order: Caryophyllales

- Family: Chenopodiaceae

- Tribe: Atripliceae

- Genre: Atriplex

- Species: Atriplex halimus L.

Etymology

- Atriplex: the name of the genus derives from the Greek «ατραφαξις» (atráphaxis) and at the same time from the Latin «atrĭplex». This name designates the genus of plants known as armuelle.

- halimus: the specific adjective comes from the Greek "halimos" which means "salty" or "salty". In relation to the ability of the plant to grow in saline soils.

Atriplex halimus flowers. Source: Colsu

Synonymy

- Atriplex domingensis Standl.

- Atriplex halimoides Tineo

- A. halimus var. serrulata (Pau) F. Alcaraz Ariza, M. Garre Belmonte & P. ​​Sánchez Gómez

- Atriplex kataf Ehrenb. ex Boiss.

- Atriplex serrulata Pau

- Chenopodium halimus (L.) Thunb.

- Obione domingensis (Standl.) SC Sand. & GL Chu

- Obione halimus (L.) GL Chu

- Schizotheca halimus (L.) Fourr.

Habitat and distribution

Native to the Mediterranean region and southern Africa, the bush is a rustic plant that grows on arid, halophilic and gypsum soils. It has a high capacity to adapt to arid climates and saline soils, withstanding intense droughts and strong winds.

It is located in thermomediterranean and mesomediterranean bioclimatic floors, the thermomediterranean with occasional frosts during winter and high temperatures in summer. As for the mesomediterranean, with frosts during winter and high temperatures in summer, both with scrub or sclerophyll forests.

It develops preferably on sandy soils with full sun exposure and requires 100-400 mm of annual precipitation. It grows from sea level to 1,000 meters above sea level in littoral environments, forming part of the native scrub, tolerates occasional frosts down to -10 ºC.

It is associated in the wild with other xerophytic species such as Atriplex glauca, Suaeda fruticosa and Salsola vermiculata. It is geographically distributed throughout the Mediterranean basin, being common in the salt flats of the Iberian Peninsula where it is cultivated as a forage shrub.

In the wild it is located in southern Europe, southwest Asia and North Africa. In the Iberian Peninsula it is located along the Mediterranean coast between Catalonia and Andalusia, including the coast of Huelva and southern Portugal.

Within the continental territory of the Iberian peninsula, it is common in semi-arid areas of Albacete, Alicante, La Rioja, Murcia, Navarra and Zaragoza. As a forage species, it has been introduced in certain arid regions in the south of the American continent, such as Argentina and Uruguay.

Foliage of Atriplex halimus. Source: Krzysztof Ziarnek, Kenraiz

Applications

Forage

It is an evergreen plant so it has foliage available all year round, being the production of browseable biomass of 2-5 Tm / ha. In fact, its nutritional value depends on seasonality, soil fertility and rainfall, its protein content being higher during spring.

It constitutes a source of food during the dry season, since it is a plant that is tolerant to water stress. It is characterized by its high palatability for livestock, high salt content and the absence of toxic elements.

It is consumed mainly by sheep, goats, cattle, game animals or camels. It is even used as a food supplement for the industrial breeding of rabbits and birds (chickens and hens) that mainly consume their terminal shoots.

As a forage species it has a high yield of carbohydrates and proteins, provided that the availability of water is frequent. In its composition it usually accumulates nitrates, which favors the production of biomass. Likewise, its frequent consumption allows reducing gas and flatulence.

However, the high concentration of salts, of up to 25% in dry matter, forces the animal to consume more water. Chlorine and sodium are among the main mineral salts, many times eliminated by the animal through urine.

The fine stems, leaves and shoots are consumed from the second or third year of establishment of the crop. It is convenient to limit browsing during summer and winter, in order to avoid accelerated deterioration of the plant.

Food

In some regions it is considered an edible plant. Its raw leaves, only passed through hot water, are used as an ingredient in salads.

Ornamental

As an ornamental plant, it is used in coastal gardens with low irrigation to form hedges or protective screens against strong winds. It is a very invasive plant if the environmental conditions are favorable, so frequent maintenance pruning is recommended.

Reforestation

The iron bush is a Mediterranean shrub that is highly resistant to long, dry and hot summer climates, with winters with frequent and intense frosts. Indeed, it is a species used to reforest degraded lands in marginal, arid areas with erosion problems.

In fact, it is used for the consolidation of loose soils, protection of soils eroded by the wind and to improve fertility and permeability. Due to its saline requirement to complete its vital processes, it is used to reforest saline soils in arid or semi-arid environments and with frequent water stress.

Atriplex halimus in its natural habitat. Source: Krzysztof Ziarnek, Kenraiz

Diseases

The Atriplex halimus species is considered a very resistant plant to attack by pests and diseases. Indeed, its high content of alkaline salts results in a toxic plant for different types of insects that attack other similar species.

References

1. Atriplex halimus. (2019). Wikipedia, The Free Encyclopedia. Recovered at: es.wikipedia.org
2. Atriplex halimus L. (2019) Catalog of Life: 2019 Annual Checklist. Recovered at: catalogueoflife.org
3. Atriplex halimus L.: Orgaza (2019) Flora Pratense and Forage Cultivated from the Iberian Peninsula. Herbarium of the Public University of Navarra. Recovered in: unavarra.es
4. Bravo, C., & Cabello, A. (2002). In vitro culture of Atriplex halimus. Notes from the Forest Tree Seed Producer Center, CESAF, (15), 9.)
5. Oliet Palá, JA & Prada Sáez, MA (2012) Atriplex halimus L. Production and management of seeds and forest plants. pp. 220-237.
6. Ruiz-Mirazo, J., & Robles, AB (2010). Establishment and development of Atriplex halimus L.: implantation techniques and grazing effect. C4 and CAM. General characteristics and use in arid and semi-arid land development programs. CSIC, Madrid (Spain), 177-190.
7. Zulueta, J., Grau, JM, & Montoto, JL (1993). Silvopascicola recovery on a previous surplus cereal crop, in Polan-Toledo. In Spanish Forestry Congress - Lourizán. Presentations and communications. Lathe II. pp 665-660.