Trifolium fragiferum: Characteristics, morphology, habitat, uses and ecological relevance

Introduction to Trifolium fragiferum: A versatile clover

trifolium fragiferum, commonly known as strawberry clover o strawberry cloverIs a perennial belonging to the family of FabaceaeThis genus is important from both an ecological and productive perspective, especially in agricultural and livestock activities. In addition to its functions as fodder and grassland restoration, trifolium fragiferum It has a series of morphological, ecological characteristics and traditional uses that make it a species of great interest.

Taxonomy and Nomenclature

• Kingdom: Plant
• Division: Magnoliophyta
• Class: Magnoliopside
• Subclass: rosidae
• Order: beans
• Family: Fabaceae (Leguminosae)
• Subfamily: faboideae
• Tribe: Trifoliae
• Gender: trifolium
• Species: T. fragiferum

Etymology: the generic name trifolium comes from Latin and means "three leaves", referring to the characteristic shape of its compound leaves. The epithet fragiferum It refers to "that which carries strawberries", due to the particular shape of its mature inflorescences that resemble a strawberry.

Synonymy: Among its botanical synonyms are: Amoria fragifera, Galearia fragifera y Trifolium bonannii, reflecting the complex taxonomic history of this extensively studied species.

Morphology and Detailed Botanical Description

• Biological type: Stoloniferous hemicryptophyte.
• Habit: Herbaceous, perennial, decumbent plant, with stems that root at the nodes and can reach up to 45 cm in length.
• Root: Main, deep, with secondary branches adapted to humid and aerated soils.
• Sheets: Alternate, stipules, petiolate, with obovate to elliptical leaflets, up to 27 x 16 mm. The margin is finely serrated and the venation is marked; the lower surface is villose along the midrib.
• Stipules: Lanceolate, acuminate, membranous and generally glabrous.
• Inflorescence: Compact, globose flower heads, 10 to 16 mm in diameter at flowering and up to 20 mm at fruiting, axillary, pedunculated, with fused bracteoles forming a basal involucre. They bear numerous flowers (up to 60 per flower head).
• Flowers: Pink corolla, free-standing standard, bilabiate calyx, zygomorphic and densely hairy on the ventral side. When ripe, the calyx swells, taking on a tomentose appearance similar to that of a strawberry.
• Fruit: A sessile, indehiscent legume with 1-2 smooth, olive-green seeds with black or dark violet spots. The seeds measure between 1,1 and 1,7 mm in length.
• Pollination: Crusade, mainly by insects (entomophilous).
• Flowering: From May to October in most temperate regions.

Habitat, Distribution and Ecology

trifolium fragiferum It is native to the Mediterranean region and has spread its presence to much of Europe, southwest Asia, northwest Africa, the Macaronesian region (including Madeira and the Canary Islands) and in humid areas of the Iberian Peninsula and the Balearic Islands.

usually found in grasslands, wet meadows, temporarily flooded pastures, river banks, lagoons and brackish lowlands. It grows from sea level to altitudes of 1500 m, adapting to clayey, sandy, limestone, or alkaline carbonate soils. It prefers fresh, deep, rich in bases, nitrified and occasionally salineThe species tolerates waterlogging well and even tolerates some salinity, making it ideal for restoring degraded grasslands in humid or poorly drained environments.

According to disturbance indicators and recent ecological studies, T. fragiferum It is a characteristic plant of heavily grazed meadows that require management through mowing and the periodic presence of large herbivores, which promotes its regeneration and dispersal.

• Seed dispersal distance class: Mainly self-dispersal, although wind and animal movement can facilitate seed fall near the parent plant.
• Light requirements: Heliophilous species, does not tolerate intense shading.
• Temperature preferences: Warm, especially in hilly environments, and tolerates wet winters.
• Acidity: It prefers soils with a pH between 5,5 and 8,5, with better development in neutral or alkaline soils.
• Nutrients: It requires soils rich in phosphorus and potassium, as well as an adequate supply of nitrogen, which it usually fixes symbiotically thanks to its root nodules.

Varieties and Subspecies

• trifolium fragiferum subsp. bonannii: Subspecies adapted to specific habitats, such as saline or temporarily flooded soils, very relevant in environmental restoration.
• Palestine: A variety selected in Australia, it is characterized by vigorous growth, high palatability, and tolerance to intensive grazing. It is especially appreciated for companion planting with grasses and is often noted for its performance in autumn and winter.
• O'Connors: Another Australian variety with finer petioles and a trailing habit that quickly forms dense lawns, although its productivity is lower than that of Palestine.
• Shearmans: Little used today, it has similar characteristics to Palestine but with less commercial presence.

These varieties show differences in precocity, productivity, and morphology, responding to the particularities of each ecosystem and livestock needs.

Productive uses and ecosystem benefits

• Forage: Its main use is in mixtures of pastures for livestock, usually combined with grasses, such as fescue, to balance nutritional intake. It provides high levels of protein and nitrogen to the soil, improving pasture vigor and facilitating meat and milk production.
• Direct grazing: Although single sowing is not recommended due to the risk of bloating in ruminants, when mixed with other species, it is highly palatable and resistant to trampling. It can maintain its yield despite pressure from livestock.
• Fixation of nitrogen: As a legume, it maintains a symbiosis with soil-fixing bacteria that allows it to enrich the soil, optimizing fertility and reducing the need for synthetic fertilizers.
• Restoration and erosion control: It is planted in areas subject to waterlogging or salinity to stabilize soils, restore degraded grasslands, and contribute to biodiversity.
• Ornamental and ecological uses: Due to its showy flowers and hardiness, it can be used in extensive gardening and as a supporting element in low-maintenance garden projects.
• Resources for pollinators: Its flowers attract pollinating insects, primarily bees and butterflies, helping to sustain populations of key auxiliary fauna in agricultural ecosystems.

Details on its cultivation and agronomic management

• Planting association: To achieve balanced and high-yield pastures, it is recommended to associate trifolium fragiferum Mainly with grasses. Under irrigated land, dry matter yields can exceed 10 tons per hectare.
• Seed dosage: In grass mixtures, the optimal dose varies between 3 and 6 kg/ha, due to its relatively slow growth during the first winter after sowing.
• Resistance and longevity: Strawberry clover stands out for its longevity and resistance to both trampling and grazing. It tolerates intense grazing and is capable of regenerating biomass after mowing or animal consumption.
• Recommended fertilization: Fertilizers rich in phosphorus and potassium are necessary to ensure rapid establishment and vigorous development, although nitrogen input is minimal thanks to its symbiosis with nitrogen-fixing bacteria.
• Adaptation to saline and humid environments: Its extraordinary tolerance allows it to thrive in soils with seasonal flooding, saline soils, and riverbanks, making it an ideal choice for marginal areas and pasture rotation schemes.

Genetic diversity and conservation

El strawberry clover It has considerable genetic diversity, which has favored the emergence of numerous varieties and regional adaptations. Its use in ecological and agricultural restoration programs contributes to maintaining genetic variability in rural and natural landscapes.

International seed banks and plant genetic resources hold collections of trifolium fragiferum, facilitating its availability for studies, genetic improvements and recovery of degraded areas.

Ecology and environmental indicators

This species acts as ecological indicator Wet grasslands, base-rich soils, and environments with controlled disturbance (mowing and occasional grazing). According to the Ellenberg scale, it is considered an indicator of:

• Light: Maximum exposure, unable to compete in shade.
• Temperature: It prefers warm and temperate environments, especially with mild and humid winters.
• Salinity: Tolerance to soils with low to moderate salt concentrations.
• Acidity: Preference for neutral to alkaline soils.
• Nitrogen: It grows preferably in nutrient-rich soils.

Their presence in grasslands ensures the persistence of biodiverse plant communities, acting as a reservoir of auxiliary flora and fauna.

Relationships with other species and botanical curiosities

• Confusion with similar species: It can be confused with Trifolium pubescens (downy clover), but the latter has a shorter flower stalk than the corresponding leaf, while in T. fragiferum the flower stalk extends beyond the leaf. Trifolium resupinatum It is annual and is distinguished by calyces with much longer teeth.
• Phytosociological behavior: Characteristic species of the Trefolio fragiferi-Cynodontion alliance, present in short, dense lawns, often with temporary flooding and grazing.
• Interactions with pollinators: Its flowers are an important source of nectar and pollen, contributing to the survival of wild bees and butterflies.
• Resilience and ecological succession: Its ability to root at nodes and colonize disturbed areas allows it to form part of secondary succession after natural or human disturbances.

Importance in biodiversity and protected ecosystems

El strawberry clover is a characteristic species of habitats included in the Natura 2000 Network, such as wet grasslands and nitrified herbaceous lands, contributing to the conservation of European biodiversity. Their presence is an indicator of good agri-environmental practices and sustainable grazing.

In ecological restoration projects, the establishment of T. fragiferum It helps restore the original structure of grasslands, prevent erosion, and support associated plant and animal communities, in addition to promoting carbon sequestration in agricultural and riparian lands.

Common names and linguistic distribution

El trifolium fragiferum It receives different names depending on the geographical area and the local language:

• Spanish: Strawberry clover, strawberry clover, strawberry clover, wild clover, wild clover
• Portuguese: Trevo-morango
• Galician: Need to
• Basque: Hirusta
• Other languages: Various local names linked to the shape of the inflorescence and traditional use

Glossary of relevant botanical terms

• Hemicryptophyte: Plant that renews its shoots at ground level, withstanding unfavorable seasons.
• Stoloniferous: With creeping stems that take root at their nodes, facilitating their expansion.
• Bilabiate: Calyx or corolla with two distinct lips.
• Decumbent: Stem prostrate or lying, but with the terminal part pointing upwards.
• Indehiscent: Fruit that does not open naturally when ripe.
• Obovate: Leaves with the widest part towards the apex.
• Marcescent: Organ that remains dry in the plant after fulfilling its function.

Distinction from other species of the genus Trifolium

• Trifolium pratense (red clover): Larger in size and more intense in color.
• trifolium repens (white clover): Most common in hay meadows, with white globose inflorescences.
• Trifolium pubescens: It is distinguished mainly by the relative length of the inflorescence peduncle with respect to the leaflet.

Scientific bases and bibliography

• Midolo G., Herben T., Axmanová I., et al. «Disturbance indicator values ​​for European plants.» Global Ecology and Biogeography.
• Tichý L., Axmanová I., Dengler J., et al. «Ellenberg-type indicator values ​​for European vascular plant species.» Journal of Vegetation Science.
• Chytrý M., Tichý L., Hennekens SM, et al. «EUNIS Habitat Classification: expert system…» Applied Vegetation Science.
• Lososová Z., Axmanová I., Chytrý M., et al. «Seed dispersal distance classes and dispersal modes for the European flora.» Global Ecology and Biogeography.
• Fabien Burki, Andrew J. Roger, Matthew W. Brown & Alastair GB Simpson. "The New Tree of Eukaryotes." Trends in Ecology & Evolution.
• Adl & al. "The Revised Classification of Eukaryotes." J. Eukaryot. Microbiol.
• Life forms. Dřevojan P., Čeplová N., Stěpánková P. & Axmanová I.

Additional resources and links of interest

• Wikimedia Commons: Images of trifolium fragiferum
• Wikispecies: Taxonomic sheet on trifolium fragiferum
• USDA Plants Database: Technical Information for North America