Introduction to Medicago lupulina (Alfalfa lupulina or black dogfish)
Medicago lupulin, popularly known as alfalfa lupulin, black dogfish o creeping clover, is a leguminous plant with a recognized presence in meadows, crops and lawns. This species belongs to the Fabaceae family and stands out for its ecological value as for your agricultural and ornamental useIf you're looking for a hardy groundcover that enriches the soil and requires minimal maintenance, understanding the characteristics and management of Medicago lupulina is essential.
Vernacular names and taxonomy
- Spanish: alfalfa, alfalfa, cart, lupulina, meligón, dogfish, black dogfish, teble, clover, creeping clover
- English: Black Medick, hopclover, yellow trefoil
- Portuguese: alfalfa-lupulin
- Galician: alfalfa lupulin, lupulin
- Catalan: small fenarola
Taxonomy:
- Domain: Eukarya
- Supergroup: Archaeplastida
- Phylum: Chloroplastida
- Division: Streptophyta
- Subdivision: Spermatophytina
- Class: Magnoliopsida
- Order: Fabales
- Family: Fabaceae
- Genus: Medicago
- Species: Medicago lupulina
Synonymy: Medicago cupaniana, Medicago willdenowii, Medica lupulina Scop., Medicago appenina Woods, among other infraspecific variants. The name "lupulina" refers to the similarity of its inflorescences to those of hops.
Comprehensive botanical description
Medicago lupulin is a short-lived annual or perennial herbaceous plant, which can grow lying on the ground or with its tips upwards. Its size generally does not exceed 50 cm heightThe stem is angular, pubescent (covered with small whitish hairs) and profusely branched, allowing it to spread out forming a dense cover.
The leaves They are alternate and composed of three leaflets (trifoliate), with the upper surface slightly hairy and the underside densely covered with hair. leaflets They are obovate to suborbicular in shape, with a toothed or serrated margin, a cuneate base and a rounded, truncated or retuse-mucronate apex. At the base, on the stem, appear the stipules, which are ovate leaflets with toothed margins.
La inflorescence It is presented in short, compact clusters of 10 to 35 flowers, with an ovoid outline and located in the leaf axils on peduncles that can measure up to 3,5 cm. flowers They are small (2 to 3 mm) and bright yellow. The calyx has five almost equal, hairy lobes, and the corolla is yellow with five unequal petals: the outermost is the "standard" (the most striking), followed by the "wings" (laterals) and the "keel" (two fused inner petals that surround the reproductive organs).
El fruit It is a small legume, slightly curved or kidney-shaped, almost black when ripe, with obvious veins, no spines and covered with a few hairs. Each fruit usually contains only one seed globose or elongated, greenish-yellow to yellowish-brown in color, with a smooth surface. These seeds are easily released when the fruit is rubbed.
La seedling It has a short, green or reddish, hairless hypocotyl. The cotyledons are sessile, oblong, or narrowly elliptical, and the first leaf is simple, while the next is trifoliate.
Variable characteristic: The density of hair on stems and leaves varies depending on soil moisture: in dry environments, the hairiness is much denser and more visible.
Distribution and habitat
Medicago lupulin It is native to Europe, much of Asia (including China, Korea, Taiwan, and the Indian subcontinent), and North Africa. It has become widely naturalized in North and South America, Japan, Australia, the Canary Islands and other Atlantic islands.
En Spain and the Iberian Peninsula It is present in almost the entire territory, including the Balearic Islands, and is also found in the temperate regions of America and other parts of the world.
It is recognized as a plant weed and ruderal, very common in meadows, roadsides, lawns, pastures, crop fields, and the margins of agricultural areas. It is also common in damp depressions, banks, and places with disturbed soils.
It has a great soil adaptability: prefers calcareous and alkaline soils, but can grow in poor soils, from moderately dry to moist, and even tolerates some salinity. It does not thrive in highly acidic soils (pH below 5,5).
This plant It can be found from sea level to considerable altitudes (up to 2900 m, especially in Mexico), withstanding a wide range of climates and temperatures.
Flowering season and life cycle
the flowering of Medicago lupulin It covers everything from the spring to autumn, depending on local climatic conditions. In temperate regions, it flowers from March to November, with fruiting occurring shortly after pollination.
Lifecycle: The plant can behave like annual or short-lived perennial Depending on the climate: in temperate and humid areas, it is usually annual, completing its cycle in a single season; in milder temperate climates, it can behave as a perennial, regenerating year after year from the roots.
Ecology and role in the ecosystem
Medicago lupulin It is a key species in soil improvement and maintenance thanks to its ability to fix atmospheric nitrogen through symbiosis with bacteria of the genus RhizobiumBy incorporating nitrogen into the soil, it benefits associated crops and enriches the pastures where it grows.
Its root system can reach deep layers, providing drought resistance and allowing it to compete even in infertile soils or during periods without rain. It is also a plant that is quite resistant to compaction and herbivore activity, and can withstand frequent grazing.
Other species of animals, such as bees and butterflies, find a food resource in their flowers, so It is considered a honey plant of beekeeping interest.
In agricultural and gardening practices, the ground cover function of Medicago lupulin contributes to the reduction of erosion, structural improvement of the soil and increased biodiversity.
Propagation and reproduction
The spread of Medicago lupulin es exclusively by seed, which is released when the fruit ripens and can sprout at different times of the year depending on humidity and temperature conditions.
- Natural dispersion: Seeds lack specific adaptations for long-distance dispersal, so most fall close to the parent plant. However, they can occasionally be dispersed by wind, water, animal movement, or human activities.
- Germination: The seeds have a high germination rate in moist soils, although they can remain dormant during dry periods, waiting for favorable conditions.
Medicago lupulina care: a complete guide to growing it
Light and temperature requirements
Medicago lupulin It is a species adapted to conditions of full light, although it is able to survive in partial shade, making it versatile for different locations within the garden or farm.
The optimum temperature for its growth is between 15 and 25°C during the day and between 10 and 20°C at nightAlthough it can withstand adverse conditions, persistently high temperatures (above 30°C) can reduce its vegetative development due to increased respiration.
Soil and pH
- Floor type: Prefers soils deep and well-drainedIt adapts well to calcareous, loamy and silty soils, and can thrive on stony ground.
- Optimal pH: It tolerates pH levels from 5,5 to 8,0, showing better growth in slightly alkaline soils. In acidic soils (pH < 5,6), it is advisable to correct the acidity with lime to promote the survival of symbiotic rhizobia.
- Salinity: Although it tolerates a certain degree of salinity, it does not thrive in excessively saline soils.
Irrigation and water needs
Drought resistance: Black dogfish is moderately resistant to dry periods thanks to its deep root system. In crops or natural pastures, it rarely requires supplemental irrigation except during prolonged periods without rain.
In well-drained soils with sufficient moisture in the deep layers, the plant maintains its vigor even during dry seasons. Waterlogging, however, is not well tolerated and can lead to root deterioration and plant death.
Fertilization and nutritional needs
Low fertilizer requirements: Thanks to its ability to fix atmospheric nitrogen, nitrogen fertilization is not necessaryHowever, a moderate supply of phosphorus and potassium can promote its establishment in soils poor in these nutrients, especially in agricultural crops.
In ornamental gardening or as a ground cover, it does not require fertilization if the soil is moderately fertile.
Pruning and maintenance
- Mowing and control: It tolerates repeated mowing very well, making it suitable for low-maintenance lawns, ground covers, and meadowsTo maintain uniform coverage, mow when the height exceeds 15-20 cm.
- Pruning: It is not necessary except to control excessively expansive areas or to remove dry debris and stimulate new shoots.
- Plagues and diseases: It is a plant that is highly resistant to common pests and diseases. It can occasionally be affected by aphids or mildew in very humid climates, but these problems rarely require specific treatments.
Uses of Medicago lupulina
- Forage: Although its biomass production is lower than that of common alfalfa (medicago sativa), its nutritional quality is good and it is suitable for feeding livestock in direct grazing and occasionally in hay.
- Honey-bearing: Its yellow flowers are an important source of nectar for bees and other pollinators.
- Soil improver: Its ability to fix nitrogen makes it an excellent crop for rotation, land reclamation, and ecological garden maintenance.
- Ornamental/Grass: Used as an environmentally friendly, low-maintenance alternative to traditional lawns, providing a dense, green cover with attractive flowering.
- Human food (traditional use): The leaves and seeds can be used in the diet, although they are limited to traditional uses or food emergencies.
Agricultural and ecological impact
Medicago lupulin can be developed as spontaneous weed in alfalfa, apple, corn and other annual crops, although the impacts are usually limited and controllable through mowing or tillage.
In rotation systems, their presence is valued for their role in improving and restoring the soil, as well as increasing local floral and fauna biodiversity.
Special and physiological characteristics
- Chromosomal number: 2n = 16
- Increase: It quickly covers the soil under favorable conditions, preventing the appearance of other weeds.
- Environmental tolerance: Capable of entering dormancy or lethargy in extreme situations of heat, cold or drought, resuming growth when conditions improve.
Medicinal benefits and traditional properties
Medicago lupulin owns properties soothing and antibacterial, although its medicinal use is limited and it is generally considered to have low therapeutic potency. In some cultures, its leaves and seeds have been used in decoctions or infusions to soothe minor irritations.
Important: The use of black dogfish for medicinal purposes should be moderate and always under professional guidance, as there are not enough scientific studies to support its safety and efficacy in humans.
Nutritional value
Average nutritional level: Its fresh leaves may contain proteins and minerals, making them suitable for reasonable quality fodder, although its production is not comparable with other intensive forage species.
Biological and ecological relationships
Medicago lupulina maintains a symbiotic relationship with nitrogen-fixing bacteria, which allows for vigorous growth in poor soils and improves the production of neighboring crops. It promotes the presence of beneficial fauna such as pollinators and forms part of plant communities that contribute to the ecological stability of meadows and grasslands.
How to distinguish Medicago lupulina from other apparently similar species
Lupulin alfalfa is easily differentiated from other clovers and legumes by its small yellow flowers grouped in dense clusters, as well as its black, kidney-shaped fruits and dense, creeping growth habit. The densely hairy underside leaflets and compact flowering pattern help distinguish it from species such as white clover (trifolium repens), whose floral color is typically white and its growth does not form such compact clusters.
Practical tips for incorporating them into your garden and crops
- Land preparation: Remove weeds and make sure the soil drains well. Lightly till the surface.
- Sowing: Sow by broadcasting or in shallow rows, barely covering the seeds with light soil. The best time is late winter or early spring.
- Irrigation: Keep the soil moist but not waterlogged until seedlings emerge.
- Maintenance: Once established, it requires minimal care. Pruning annually or after flowering prolongs its life and improves coverage.
- Rotation and green manure: You can grow it as green manure, incorporating the biomass into the soil to enrich it with nitrogen before planting demanding crops.
Photographs and visual gallery
The photo gallery includes descriptive images of the plant in different stages of growth, flowering, and coverage. All photos are centered and full-size to appreciate the details of the plant. Medicago lupulin in the field and garden.
Glossary of common botanical terms in Medicago lupulina
- Stipules: Small leaf-like structures at the base of the petiole.
- Bunch: Inflorescence composed of flowers arranged on a common axis.
- Keel: Fusion of two lower petals in papilionate flowers.
- Obovate: Inverted egg-shaped, wider at the apical end.
- Hairy: Covered with fine hairs.
- serrulated: Leaf margin with small, closely spaced teeth.
Additional references and resources
- Correa, MN Patagonian Flora. Dicotyledoneae: Dialipetalas.
- Cronquist, A., Holmgren, N.H., Reveal, J.L., et al. Vascular plants of the Intermountain West, USA
- Espinosa G., FJ and J. Sarukhán. Manual of weeds of the Valley of Mexico.
- McVaugh, R. Leguminosae. Flora Novo-Galiciana.
- Rzedowski, G.C. de and J. Rzedowski. Phanerogamic flora of the Valley of Mexico.
- Villaseñor R., JL and FJ Espinosa G. Catalogue of weeds of Mexico.
- Links to databases: Missouri Botanical Garden, CONABIO SIIT, Tropicos, IPNI, USDA PLANTS, Jepson Manual, ePIC of the Royal Botanic Gardens, Kew.
Medicago lupulin It has established itself as an ideal plant for use in sustainable agriculture, organic gardening, and soil restoration, thanks to its hardiness, ease of establishment, low maintenance, and notable environmental value. Its presence promotes biodiversity, improves soil fertility, and enriches green spaces with its showy and prolonged flowering.