ASPARAGUS: CHARACTERISTICS, PROPERTIES, CONTRAINDICATIONS, CULTIVATION - BIOLOGY - 2024

The asparagus (Asparagus acutifolius) is a perennial plant belonging to the Liliaceae family. This species of wild asparagus known as wild, thorny or spicy asparagus, is native to the Mediterranean basin.

It is a shrubby plant of medium size and climbing growth that is distinguished by the large number of dark green cladodes in its foliage. Young shoots or young asparagus are finer than regular asparagus and have a much more intense flavor.

Wild asparagus (Asparagus acutifolius). Source: pixabay.com

This genus of plants lacks true leaves and its structure is made up of modified stems called cladodes, which have a chlorophyll function. In effect, these short, linear and spiny structures are grouped in bunches and resemble true leaves.

Of this species, the well-known "wild asparagus" are wildly harvested, considered firmer and better tasting than the cultivated asparagus of Asparagus officinalis. The tender shoots are highly palatable in gastronomy, being eaten roasted, fried or sautéed with eggs.

In traditional medicine, dried asparagus is used for diuretic purposes, fluid retention, urinary problems, or liver and kidney failure. However, its consumption is contraindicated in people with biliary or kidney diseases and patients with nervous disorders.

General characteristics

Appearance

The Asparagus acutifolius species is a perennial shrub or subshrub, gynoidic in character, measuring 150 to 300 cm in height. It is characterized by a very small, thick and fleshy rhizome from which multiple multi-annual stems develop, which constitute the usable part of the plant.

It differs from the other asparagus by its climbing plant bearing and the presence of a large number of cladodes around the plant. Slender stems covered with scaly and spirally arranged leaves emerge from the rhizome in spring: the familiar wild asparagus.

Stem

The semi-woody, cylindrical, rigid and slightly pubescent stems are arch-descending in shape with more or less obvious ribs. Numerous branches sprout from the stems covered by green cladodes, sometimes glaucous and grayish when mature.

Leaves

The 5-10 mm long leaves are scaly and triangular in shape with a brownish band and hyaline margins. They usually cluster at the base of a 3-5 mm rigid spur along the main branches.

The cladodes are semicircular or elliptical modified leaves 2-8 mm in diameter, arranged in the axillary position. Each cladode has several prominent nerves, being green in color and papillose in texture, sometimes glaucous, slightly rigid and persistent.

Asparagus flowers (Asparagus acutifolius). Source: Isidre blanc

flowers

The hermaphroditic or unisexual flowers, solitary or in pairs, are arranged in the axils of the cladodes through a short articulated pedicel. The yellowish-green tepals are fasciculated at the end and welded at the base and are protected by bracts that completely cover the base of the peduncle.

Fruit

The fruit is a globular berry 5-8 mm in diameter, green when tender and blue-blackish when ripe. Inside it, 1-3 seeds are formed in a hemispherical shape. Pollination is generally entomophagous and flowering occurs from May to September.

Chemical composition

During spring, long, thin, green stems that are edible grow at the base of the plant. These stems, called "shoots" or asparagus, are highly valued at a culinary or medicinal level due to their high nutritional content.

Asparagus harvested from the Asparagus acutifolius species are high in fiber, vitamins (A, C, E) and folic acid (vitamin B ₉). Also, various mineral elements among which chromium stands out, which is involved in the transport of glucose through the bloodstream.

One of the main active principles present in this species is glutathione, useful for purifying and eliminating harmful or toxic elements from the body. In fact, its ability to scavenge various radicals prevents the formation of various types of cancer, especially colon, bone, laryngeal, breast and lung cancer.

The wild asparagus has a high content of antioxidants, being useful to prevent physiological alterations related to aging. Clinical studies have confirmed its benefit in reducing or slowing down the process of biological degeneration due to age.

In addition, it has a high content of the amino acid asparagine, which has a diuretic action. In this way, it favors the elimination of excess sodium from the body. It is rich in potassium, an essential element to regulate blood pressure and the proper functioning of the muscles, especially the heart.

The presence of the polysaccharide inulin is highly beneficial for the digestive tract, since it constitutes a nutritional source for the intestinal bacterial flora. At the same time, it provides an effective anti-inflammatory effect to the entire body.

Asparagus fruits (Asparagus acutifolius). Source: Isidre blanc

Nutritional value per 100 g

- Energy: 40-45 kcal

- Water: 94 g

- Fats: 0.15-0.25 g

- Sugars: 0.37 g

- Fiber: 1-3 g

- Vitamin A: 948 IU

- Vitamin B ₁: 0.120 mg

- Vit. B ₂: 0.130 mg

- Vit. B ₃: 1,202 mg

- Vitamin B ₅: 0.184 mg

- Vitamin C: 31.8 mg

- Folic acid (vitamin B ₉): 191 mg

- Calcium: 20-25 mg

- Phosphorus: 60-65 mg

- Iron: 0.75-1.00 mg

- Magnesium: 14 mg

- Manganese: 0.203 mg

- Potassium: 253 mg

- Zinc: 0.59 mg

Habitat and distribution

The Asparagus acutifolius species is native to the Mediterranean region, wildly it is located in the coastal area where the olive tree (Olea europaea) is grown. Its habitat is located on loamy and humid soils, preferably sandy soils of calcareous origin, well drained and with a high content of organic matter.

It is located on steep terrain or hilly lowlands, associated with deciduous forests or on dry and sunny soils in xerophilous environments. A limitation of its adaptability to various ecosystems is the altitudinal range, its development preference being below 600 meters above sea level.

Geographically it is distributed throughout the Mediterranean basin, being located throughout the Iberian Peninsula, except the Atlantic coast and the Balearic Islands. It can also be found in south-central Italy, Greece and southern France. It has recently been introduced in Costa Rica.

Wild asparagus in its natural habitat. Source: Gianni Careddu

Taxonomy

- Kingdom: Plantae

- Division: Magnoliophyta

- Class: Liliopsida

- Order: Asparagales

- Family: Liliaceae

- Subfamily: Asparagoideae

- Genus: Asparagus

- Species: Asparagus acutifolius L.

Etymology

- Asparagus: the genus name comes from the Latin term "sparagus" which in turn derives from the Greek "aspharagos" or "asparagos" that precedes the Persian "asparag". All these terms mean "sprout" in reference to the type of propagation of the plant.

- acutifolius: the specific adjective derives from the Latin "acutifolius, -a, -um," in allusion to the sharp or spiny shape of its leaves.

Synonymy

- Asparagus aetnensis Tornab.

- Asparagus ambiguus De Not.

- A. brevifolius Tornab.

- A. commutatus Ten.

- Asparagus corrudav Scop.

- Asparagus inarimensis Tornab.

Health properties

Wild asparagus is a plant rich in vitamins, mineral salts, fibers, carbohydrates and secondary metabolites that provide various health benefits. Due to its diuretic effect, it is an effective detoxifier of the body, helps prevent type II diabetes and is a natural anti-inflammatory.

Its regular consumption improves intestinal functions and contributes to good digestion. Likewise, its antioxidant function is valuable for the prevention of some types of cancer. It also promotes the better functioning of the nervous system, the cognitive regeneration of the brain and prevents certain cardiovascular diseases.

Wild asparagus for culinary use. Source: pixabay.com

It provides a good dose of vitamins and minerals, regulates blood sugar content and is an effective diuretic to detoxify the body. In this sense, it is a recommended dietary supplement for patients with hypertension, edema or fluid retention.

Likewise, it is a vegetable that improves digestion and regulates intestinal function, being effective for patients suffering from constipation. On the other hand, the high content of folic acid in combination with vitamin B ₁₂ prevents the incidence of age-related cognitive disorders.

It is indicated as a food that helps prevent certain cardiovascular diseases, as well as improve the proper functioning of the nervous system. In summary, the consumption of wild asparagus is recommended in cases of:

- Sugar in the blood.

- Edema or fluid retention.

- Constipation.

- Hypertension.

- Digestion problems.

- Detoxification.

- Cardiovascular diseases.

- Cognitive impairment.

- Nervous system disorders.

Ripe fruits of asparagus (Asparagus acutifolius). Source: Gianni Careddu

Consumption contraindications

Wild asparagus is a wild species that is harvested directly from the field and is sometimes confused with toxic plants that have adverse health effects. In addition, it grows in urbanized or intervened sites, being susceptible to contamination by pesticides in orchards and gardens, which is why its collection should be supervised.

The adverse effects of its intake are mild, and tend to disappear after a short time. Due to its high potassium content, it has a diuretic effect and, in general, people tend to experience an increased diuresis.

On the other hand, the high content of carotenoids causes a discoloration of the skin known as hypercarotinemia. However, this effect is generally harmless and tends to disappear when its consumption is restricted. In certain people, its direct contact with the skin causes dermatitis.

In summary, its consumption is restricted in patients with diseases of the urinary system, either due to the action of the kidneys or the bladder. Also, in people with nervous disorders or who frequently suffer from insomnia.

Culture

Wild asparagus is harvested directly in the field, as it is a common wild plant in the Mediterranean region. The shoots or asparagus are thinner, harder and more consistent than the common asparagus, so they are consumed in tortillas or grilled.

Its commercial multiplication has made it possible to determine that this wild species offers the possibility of obtaining up to two harvests a year in less space and time. Despite the fact that its performance is not comparable with common asparagus, its organoleptic characteristics are appreciable both in gastronomy and in traditional medicine.

Asparagus (Asparagus acutifolius). Source: Zidat

For the establishment of this species, a fertile and loamy soil, with high sand content, is recommended to facilitate drainage. Usually, moist soils tend to favor the presence of soil pathogens that affect the quality of asparagus.

The seeds for planting the crop are collected from ripe fruits in late autumn, separated and dried in the shade. Sowing is done under greenhouse conditions with controlled conditions in early spring on a fertile substrate.

Once the asparagus are vigorous and sufficiently developed, they are transplanted to the final ground. This activity is carried out in mid-June-July, trying to maintain a planting density of 30-35 cm between plants and 120-150 cm between rows.

During the development of the plantation it is advisable to apply moderate watering, trying to keep the soil slightly moist, as well as fertilizing and mulching. The next year the first shoots are cut to promote the development of the crop and the commercial harvest begins the second or third year after planting.

Requirements

Wild asparagus does not tolerate severe cold in winter or occasional frosts in spring. This is because it is a typical Mediterranean climate plant that requires warm and cool climates.

It develops on sandy soils with a high content of organic matter and well drained, it tolerates water scarcity better than excess humidity. Low temperatures tend to slow down their growth and frost can cause serious physiological damage.

It is a crop that grows under full sun exposure, although it tolerates semi-shady conditions during the initial phases of growth. It is recommended to keep the soil moist during the summer season, and to apply fertilizers or organic fertilizers during the spring and summer seasons.

Detail of the cladodes of Asparagus acutifolius. Source: Hectonichus

Plagues and diseases

Pests

- Heliothis sp.: Lepidopteran moth that devours the aerial part of the plant.

- Myzus sp.: Aphid that damages tender tissues and causes the formation of short internodes.

- Ophiomya simplex: the well-known asparagus miner is a dipteran that feeds on the cortical tissue or cortex of the stem.

- Parahypopta caestrum: the larvae of this moth excavate galleries that damage the rhizomes and roots.

- Tetranychus urticae: this mite deteriorates the foliage of the plant causing a yellow stippling that reduces the commercial quality of the crop.

- Thrips: Thysanopteran insects that reduce the photosynthetic capacity of the plant, cause wilting and twisting of the branches.

Diseases

- Botrytis sp.: phytopathogenic fungus that affects the base of the plant, deteriorating the asparagus.

- Corynebacterium sp.: Gram positive bacillus that causes a bacterial tumor that affects the base of the stems.

- Fusarium sp.: Filamentous fungus in the soil that damages the roots and the vascular system.

- Puccinia asparagi: causal agent of asparagus rust, which affects the main and secondary branches of feather dusters.

- Rhizoctonia violacea: fungal pathogen that affects roots and rhizomes.

- Stemphylium vesicarum: phytopathogenic fungus that causes the disease known as burning of asparagus, deteriorating the basal part of the leaves.

- Xanthomonas campestris: bacterium that causes necrotic lesions on the leaves, shoots and tender tissues.

References

1. Asparagus acutifolius. (2019). Wikipedia, The Free Encyclopedia. Recovered at: es.wikipedia.org
2. Bissanti, G. (2017) Asparagus acutifolius. An Ecosustainable Mondo. Recovered in: antropocene.it
3. Blasco-Zumeta, J. (2017) Asparagus acutifolius L. Flora of Pina de Ebro and its Region. Liliaceae family. Recovered in: blascozumeta.com
4. Rodríguez Gonzáles, A. (2015) Esparraguera. Asparagus. Asparagus acutifolius. The Natural Serranía. Recovered in: laserranianatural.com
5. Sánchez García, S. (2015) Esparraguera (Asparagus acutifolius L.). ADENE - Association for the Defense of Nature - Enguera.
6. Vallejo Villalobos, JR, Peral Pacheco, D. & Carrasco Ramos, MC (2009). Annotations to the ethnobotanical and medicinal knowledge of Extremadura asparagus. Naturopathic Medicine, 3 (1), 41-46. ISSN: 1576-3080.