Introduction to Sonchus oleraceus
The Sonchus oleraceusSweet chicory, popularly known as sow thistle, lechuguilla, cerrajón, or sweet chicory, is an annual (rarely biennial) herbaceous plant belonging to the Asteraceae family. Its cosmopolitan presence and ability to adapt to different environments have made it one of the most recognized weeds and wild plants in both rural and urban settings. In addition to its ecological role, it is notable for its applications in food and traditional medicine.
Sonchus oleraceus has enjoyed recognition since ancient times for its nutritional characteristics and its therapeutic use, which has motivated its study and collection in different cultures around the world.
Taxonomy and Common Names
- Scientific name: Sonchus oleraceus L.
- Family: Asteraceae (Compositae)
- Synonyms: Sonchus ciliatus, Sonchus laevis, Sonchus jacinthoides, Sonchus parviflorus
- Common names in Spanish: sow thistle, sow thistle, milk thistle, sweet chicory, borage, milk thistle, endive, pork purslane, horsetail, mitihuaraca, borage
- Names in indigenous languages: Tlamatsalin, chichicaquítl (Nahuatl); tsktsuk chekamiti (purépecha)
- English names: Sowthistle, common sowthistle, annual sowthistle
The diversity of names reflects their wide distribution and the value attributed by different cultures.
Geographic Distribution and Habitat
Native to the Mediterranean basin, Europe and western AsiaSonchus oleraceus has naturalized and spread to all continents, adapting to temperate and subtropical climates. It is especially abundant along roadsides, fields, crops, gardens, meadows, and urban areas. It is considered a ruderal and weed plant, capable of thriving in disturbed, nitrogen-rich soils, as well as in agricultural and wasteland.
- In Mexico, it is found in most states, from lowland areas to regions with altitudes above 3000 meters.
- In the rest of the world it is found in Africa, Asia, Oceania and America, including North America, South America and island areas.
Its adaptability allows it to establish itself in compact, sandy, clayey and even stony soils, as long as it has some humidity and moderate sun exposure.
Botanical Description and Morphology
Lifestyle: An annual or biennial herbaceous plant that can reach 15 centimeters to over 1,2 meters in height, or even more in optimal conditions. It has erect, hollow, glabrous stems, sometimes with glandular hairs, ranging in color from green to reddish, with marked branching at the top.
- Sheets: Arranged in a basal rosette during their youth, they develop into clasping, deeply lobed or pinnatisect stem leaves with pointed auricles at the base and toothed margins or fine spinules. They vary in length (up to 40 cm) and are usually wider and entire at the top of the stem.
- Stems: Cylindrical, robust, hollow and furrowed, generally glabrous, although they may have glandular hairs.
- Inflorescence: Chapters grouped in corymbs or terminal panicles, each chapter composed of numerous ray florets Bright yellow in color. Involucre of herbaceous bracts, glabrous or with glandular hairs, campanulate and 10 to 13 mm long.
- Flowers: All the flowers in the flower head are ligulate (not tubular), yellow, and contain white latex. They are primarily insect-pollinated, although they can also self-pollinate.
- Fruits: Oblong, compressed achenes, brown, finely wrinkled, and with three longitudinal ribs; crowned by a white pappus that facilitates wind dispersal.
- seedlings: Hypocotyl hairless, cotyledons oval or elliptical in shape and alternate leaves at the beginning of growth.
- Chromosomes: Chromosomal number 2n=32.
Differences with other species of Sonchus
Within the genre sonchus There are related species such as Sonchus tenerrimus (fine lock, wall lock or lechuguilla) and Sonchus asper (thistle or cardina), with similar morphological characteristics. However, Sonchus oleraceus is distinguished by:
- The auricles at the base of the stem leaves are pointed and not rounded.
- The leaves are more widely lobed and less spiny than S. asper.
- The flowers are exclusively ligulate and intense yellow.
These differences, together with the stem structure and the fruit, allow its identification in the field, avoiding confusion with similar species such as the dandelion (Taraxacum officinale).
Life Cycle, Phenology and Ecology
Sonchus oleraceus shows rapid development From germination, the plant completes its cycle in just a few weeks under optimal humidity and temperature conditions. After emergence, the plant forms a basal rosette before producing a flower stem and branching.
- Phenology: It flowers and bears fruit practically all year round in temperate climates, being especially prolific in spring and autumn.
- Pollination: Mainly entomophilous (insect-pollinating), although self-pollination may occur.
- Dispersion: The pappus allows the anemochoric dispersal of seeds, facilitating their colonization and expansion into new habitats.
Sonchus oleraceus is a pioneer plant, important in processes of ecological succession and recovery of disturbed soils, in addition to serving as refuge and food for various insects and other species.
Chemical Composition and Active Ingredients
The phytochemical richness of Sonchus oleraceus justifies its medicinal and nutritional applications. Its main components include:
- Flavonoids: Luteolin, cynnaroside, quercetin
- Lactones and sesquiterpene glycosides
- alkaloids, anthraquinones and coumarins
- Polyphenols and tannins
- Steroids and triterpenes (lupeol)
- Vitamins: Vitamin C (ascorbic acid) and B vitamins stand out.
- Minerals: Potassium, calcium, magnesium and iron
El white latex It contains phenolic compounds and is responsible for its protective properties and its slightly bitter taste.
Medicinal Properties and Therapeutic Uses
The sow thistle has been used in folk medicine from different cultures for its healthy effects:
- Mild laxative and carminative action: Helps regulate intestinal transit and relieve gas.
- Diuretic and purifying: Promotes the elimination of fluids, helping with kidney and liver conditions.
- Cholagogue: Promotes the production and release of bile, useful in digestive and liver problems.
- Anti-inflammatory: Its phenolic compounds help reduce inflammation, both internally and when used topically.
- Antioxidant: Its flavonoid content protects against oxidative stress and cellular aging.
- Antimicrobial: It has been used to treat minor infections, especially in external use using poultices.
Other popular uses include the treatment of fever, asthenia, pain, rheumatism, skin inflammation, and indigestion. Latex, although useful in poultices, can cause dermatitis in sensitive individuals. Cautious use is always recommended, as is avoiding direct contact with mucous membranes or open wounds.
Food and Nutritional Use
The tender leaves and young shoots of Sonchus oleraceus They have been used as a vegetable and in salads since ancient times. They are highly prized for their fresh flavor, slight bitterness, and crunchy texture.
- In raw: Clean leaves in salads, along with other wild herbs.
- Cooked: They can be prepared in stews, sautéed, or boiled similarly to spinach, and they combine well in omelets and scrambled eggs.
- Drinks and decoctions: Traditionally, infusions of dried leaves and roots have been made for digestive and purifying purposes.
- Use of the root: In some places, the roasted and ground root is used to prepare a coffee-like beverage.
Sonchus oleraceus is an ingredient in preboggion, a traditional herb blend found in Ligurian cuisine. This highlights its importance in the diets of various regions.
Nutritional value
Sonchus oleraceus is a relevant source of micronutrients:
- High content in Vitamin C, polyphenols and antioxidant compounds.
- Minerals such as calcium, potassium, magnesium and iron, offering an interesting nutritional complement in plant-based diets.
- Low in calories and rich in dietary fiber, suitable for balanced diets.
Its pleasant flavor and culinary versatility have motivated its use, especially in times of scarcity, as a safe and healthy food resource.
Agronomic Importance, Biology and Effects on the Agroecosystem
Sonchus oleraceus behaves like competitive weed in numerous crops, primarily affecting slow-growing species or those with wide spaces between plants. Dense populations can cause:
- Competition for nutrients, light, and water, reducing the production of crops such as sunflowers, tobacco, peanuts, tomatoes, corn, beans, among others. For more information on weed control, check out our best seasonal plants.
- Host pests and diseases, as it is a host to various insects (aphids, nematodes) and phytopathogenic fungi.
- Interfere with agricultural rotations and weed control due to their rapid spread.
Despite its potential negative impact, it also contributes to The Biodiversity and can serve an ecological function as a refuge for beneficial fauna and a floral resource for pollinators.
Control and Management Strategies
- Cultural control: Hand weeding, although costly, is very effective, especially in orchards and vegetable gardens. It is essential to remove plants before flowering to prevent seed dispersal.
- Good farming practices: Optimizing planting density and row spacing reduces weed growth.
- Chemical control: Pre-emergence herbicides (simazine, atrazine, dichlobenil, chlortriamide, pyrazon, linuron, ametryn, prometryn, metribuzin) and post-emergence herbicides (rimsulfuron, 2,4-D, MCPA, paraquat, glyphosate, among others) are used, and the specific product must be selected based on the crop. Herbicide rotation is necessary to prevent the development of resistance.
- Resistors: International cases of resistance to chlorsulfuron and other herbicides have been reported, so alternating methods and constant monitoring are recommended.
Etymology and Historical Aspects
The term sonchus comes from the Greek “sonkhos”, already cited in classical antiquity by authors such as Pliny the Elder, Theophrastus and Dioscorides to designate similar plants. Oleraceus derives from the Latin “oleraceus”, related to vegetables or greens, alluding to the traditional food use of the plant.
Historically, sow thistle has been valued as an emergency food and folk remedy in various European, African, and Asian civilizations.
Precautions, Toxicity and Contraindications
Sonchus oleraceus is considered safe as a food and as a medicinal plant used in appropriate doses. However, it is important to keep the following recommendations in mind:
- Avoid prolonged contact with latex, as it may cause skin irritation in susceptible individuals.
- Do not collect plants located near contaminated areas (roadsides, industrial zones), to avoid the accumulation of heavy metals or pollutants.
- Excessive consumption may cause unwanted laxative effects, especially in children or sensitive individuals.
- Consult a specialist before using the plant as a sole treatment for kidney, liver, or metabolic problems.
Traditional, Cultural Uses and Curiosities
Beyond its direct applications in food and phytotherapy, Sonchus oleraceus has been part of various traditions:
- In popular Mediterranean cuisine, especially in Italy and Spain, its young leaves are harvested before flowering.
- In Mexico and Central America it is used as fodder and occasional food for both humans and animals.
- Its roasted root juice was used as a substitute for coffee in times of scarcity.
- Its inclusion in the Ligurian preboggion makes it a valuable component of culinary ethnobotany.
Botanical Classification and Extended Taxonomy
- Kingdom: Plant
- Subkingdom: Tracheobionta (vascular plants)
- Superdivision: Spermatophyta (seed plants)
- Division: Magnoliophyta (flowering plants)
- Class: Magnoliopsida (dicotyledons)
- Subclass: Asteridae
- Order: Asterals
- Family: Asteraceae
- Gender: sonchus
- Species: Sonchus oleraceus
References and Sources for Further Information
- Botanical manuals and catalogues of national and international reference.
- Specialized websites such as Flora of the Bajío, Flora of North America, CalFlora, and Plants of Hawaii offer useful images and descriptions for identification.
- Biodiversity databases: Global Biodiversity Information Facility (GBIF), SIIT-ITIS, USDA PLANTS Database.
- Scientific literature accessible through PubMed, PubMed Central, Kew Royal Botanic Gardens, and other repositories.
Sonchus oleraceus, with its remarkable adaptability, nutritional value, and health-promoting properties, stands out as one of the most versatile and useful wild plants worldwide. Its study and responsible use can provide benefits to health, nutrition, and agricultural and urban ecosystems.