Bird's-Foot Trefoil

Lotus corniculatus is native to Europe, North Africa, and temperate Asia, and has been widely introduced to North America, South America, Australia, and New Zealand as a forage crop and soil stabilizer.

• Found at elevations from sea level to approximately 2,500 meters in mountainous regions of Europe
• Occurs in an exceptionally wide range of habitats: grasslands, meadows, roadsides, embankments, coastal cliffs, sand dunes, waste ground, and even cracks in pavement
• The genus Lotus diversified primarily in the Mediterranean region during the late Tertiary period, with many species adapting to dry, open habitats
• The species has been known since antiquity — the generic name "Lotus" derives from the Greek "lotos," an ancient name for several leguminous plants mentioned by Theophrastus and other classical authors
• Introduced to North America in the mid-19th century as a forage legume, where it has become widely naturalized and is now considered both a valuable wildlife plant and a minor agricultural weed
• Bird's-Foot Trefoil was formerly classified within a broadly defined Lotus but molecular studies have reorganized many species into segregate genera

Lotus corniculatus is a herbaceous perennial with a prostrate to ascending habit and distinctive trifoliate-plus-stipule foliage.

Root System:
• Deep, woody taproot reaching 30–90 cm, providing access to soil moisture during drought
• Root system bears characteristic nitrogen-fixing nodules containing Rhizobium bacteria, enabling the plant to thrive in nitrogen-poor soils

Stems & Habit:
• Stems prostrate to ascending, branching freely from the base, 10–40 cm long
• Smooth, slender, often rooting at the nodes where they contact moist soil
• Plants form mats or loose cushions that can spread 20–40 cm across

Leaves:
• Appearing palmate with 5 leaflets, but technically trifoliate with 2 additional stipule leaflets at the base
• Each leaflet elliptic to obovate, 5–15 mm long, grey-green, hairless
• Leaves fold along the midrib at night or in adverse weather (nyctinastic movement)

Flowers:
• Pea-like (papilionaceous), 5–10 mm long, in umbels of 3–7 on long peduncles
• Bright yellow, often tinged orange-red — especially as flowers age — producing the distinctive "egg-and-bacon" bicolour
• Standard (upper petal) erect, wings (side petals) spreading, keel (lower petals) enclosed
• Blooming period extends from May through September, with peak bloom in June–July

Fruit & Seeds:
• Slender, cylindrical pods (2–3 cm long), turning brown and dehiscing with a twisting motion
• Pods borne in clusters of 5–10, spreading outward in a radiating pattern that perfectly resembles a bird's foot — the source of the common name
• Each pod contains 10–20 small, dark, kidney-shaped seeds

Bird's-Foot Trefoil is one of the most ecologically valuable wildflowers in temperate grassland ecosystems worldwide.

Habitat:
• Exceptionally wide habitat tolerance: grasslands, meadows, roadsides, embankments, coastal cliffs, sand dunes, quarry floors, and waste ground
• Tolerates poor, droughty soils, heavy clay, compacted ground, and salt spray
• Fixes atmospheric nitrogen via root nodules, enriching the soil for neighboring plants
• Often one of the first legumes to colonize bare or disturbed ground

Pollination:
• Flowers are visited by an enormous range of insects — bees (particularly bumblebees and solitary bees), hoverflies, butterflies, and beetles
• The tripping mechanism of the keel petal ensures pollen is deposited on the underside of visiting bees
• Nectar production is copious, making it one of the most important nectar sources in European grasslands

Adaptations:
• Nitrogen fixation allows colonization of the most nutrient-impoverished soils
• Deep taproot provides drought tolerance unmatched by most other meadow wildflowers
• Prostrate growth habit and ability to root at nodes allows vegetative spread and tolerance of grazing, mowing, and trampling
• Cyanogenic glycosides in the foliage deter herbivory by some insects and molluscs, though several butterflies have evolved to tolerate or even sequester these compounds

Bird's-Foot Trefoil is not considered threatened and is one of the most widespread and common wildflowers in its native range.

• The species benefits from both agricultural disturbance and conservation management of grasslands
• In some regions where it has been introduced (North America, Australia, New Zealand), it is considered both a valuable forage plant and a minor invasive species in natural habitats
• No specific conservation measures are needed for the species itself, though the grassland habitats it supports are declining

The leaves of Bird's-Foot Trefoil are edible in moderation and have been used as a famine food in Europe. The plant contains condensed tannins and moderate protein levels, making it valuable as forage. However, it is not a significant food crop for humans.

Bird's-Foot Trefoil contains cyanogenic glycosides (primarily lotaustralin and linamarin) that can release hydrogen cyanide when plant tissue is damaged. While generally safe for grazing livestock at normal consumption levels, the plant can be toxic in large quantities, particularly to horses. Most ruminant livestock tolerate it well. The cyanide content varies between populations and is higher in plants from higher elevations.

Bird's-Foot Trefoil is an exceptionally easy and rewarding plant for wildflower meadows, wildlife gardens, and low-maintenance lawns.

Light:
• Full sun to very light shade; flowers best in full sun
• Tolerates exposed, open positions

Soil:
• Exceptionally adaptable — thrives in poor, droughty, sandy, gravelly, or clay soils
• pH tolerance: 4.5–8.5 (extremely wide range)
• No fertilizer required; fixes its own nitrogen
• Excellent drainage preferred but tolerates seasonal wetness

Watering:
• Very drought-tolerant once established; the deep taproot accesses deep soil moisture
• Water seedlings during establishment; after that, no supplemental watering needed

Temperature:
• Extremely cold-hardy (USDA Zones 3–9)
• Tolerates hot, dry summers and cold, wet winters equally well

Propagation:
• Sow seed directly in spring or autumn; scarification or cold stratification improves germination
• Can be over-seeded into existing lawns and meadows
• Plants self-seed freely and persist for many years
• Can be mown to 5 cm and will regrow vigorously

Common Problems:
• Generally pest-free and trouble-free
• May be attacked by fungal diseases (crown rot, stem rot) in persistently wet conditions
• Can become overly dominant in fertile soils where it outcompetes non-legume companions
• Seed pods may be parasitized by weevil larvae

Bird's-Foot Trefoil has significant agricultural and ecological uses.

• Widely planted as a forage legume for cattle and sheep, valued for its high protein content, drought tolerance, and non-bloating properties (unlike alfalfa and clover)
• Used in mine reclamation, road embankment stabilization, and erosion control due to its deep roots and nitrogen-fixing ability
• One of the most important wildlife plants in European and North American grasslands — essential larval food plant for Common Blue, Silver-studded Blue, Green Hairstreak, and Dingy Skipper butterflies
• Excellent bee plant and nectar source; honey derived from Bird's-Foot Trefoil is light-colored and mild-flavored
• Used in low-maintenance lawn alternatives and wildflower meadow mixes