Lotus corniculatus - Bird's foot trefoil

Lotus corniculatus, or Common Bird's-foot Trefoil, is a herbaceous perennial plant with deciduous foliage resembling clover. It forms a low, carpeting clump which produces flowers from June, sometimes May. The flowers are similar to sweet peas, in golden yellow, with some of them blooming in orange tones. This easily self-seeding, wild perennial combines natural qualities of resistance to both cold and drought, and is very ornamental. It finds a place in sunny rockeries and adds a natural touch to borders.

Bird's-foot Trefoil belongs to the vast Fabaceae family, formerly called legumes, the third largest in the plant world with nearly 23,000 species. It is the family of Beans and Peas, and many ornamental genera, ranging from Wisterias to Judas Trees. There are more than a hundred species of Bird's-foot Trefoil, whose scientific name Lotus should not be confused with the Lotus (common name), whose botanical name is Nelumbo. Lotus corniculatus is native to southern Eurasia and is part of the French flora. Common Bird's-foot Trefoil originally grew in alpine lawns and meadows, on basaltic and limestone plateaus and in alluvial valleys. It has since spread freely into agricultural meadows, roadsides, embankments and wasteland. Although toxic, the plant is used in medicine as a nervous sedative and as a green manure in agriculture. Fabaceae host bacteria in nodosities that develop on their roots, and these organisms capture atmospheric nitrogen. This characteristic allows plants in this family to succeed in growing in soils very poor in nitrogen, while this element is essential for plant growth.
The Corniculate Bird's-foot Trefoil is a very hardy perennial (down to -25°C/-28°C) and quite drought-resistant, capable of establishing itself on very infertile, calcareous to neutral soils. It forms a low clump, 10 to 20 cm high with a 30 to 40 cm spread. The foliage consists of small trifoliate, medium green leaves which visually pair very well with the golden yellow of the flowers. These appear from May and June, depending on the region, and renew themselves until September, or even October. The flowers are of the papilionaceous type (because their shape resembles a butterfly), with five sepals: one upright called the banner, two lateral ones that constitute wings and two lower ones grouped into a keel. The flowers, measuring approximately 1.5 cm, are grouped in umbels of two to six flowers. Orange flowers mix with yellow ones on the same plant, which only enhances the ornamental interest of the plant. After flowering, a cylindrical, elongated, purplish pod forms. It is terminated by a small beak, hence the species name of the plant. Upon ripening, the pod expels the seeds a distance away, which allows the Bird's-foot Trefoil to spread. Furthermore, its deep rooting (up to 1 m) allows it to stabilise soils.

The Corniculate Bird's-foot Trefoil is a very robust plant, well adapted to poor or calcareous soils and sunny exposures, making it a perfect plant for rockeries and dry-stone walls, over which it will elegantly cascade. Its natural appearance is also great for naturalistic gardens, which favour wilder, more natural plants. You can plant it at the edge of a border with a Colutea media 'Cooper Beauty', another Fabaceae, but shrubby, better known as Bladder Senna. This variety with coppery orange flowers is also decorative for its large, inflated pink pods, which children love to pop under their feet. In the background, you could place a Cornus Mas, the Cornelian Cherry, which can reach 4 or 5 m in height and whose yellow flowers bloom in late winter. If you prefer to plant it in a rockery, your Bird's-foot Trefoil will get along well with Soapwort from Montpellier, whose multitude of small pink flowers will contrast pleasantly with its yellow flowers.