Lysimachia vulgaris - Loosestrife

Lysimachia vulgaris, also known as common loosestrife or yellow loosestrife, is a beautiful perennial plant found in wet and open areas of temperate regions in Eurasia. Its creeping rhizome allows it to quickly colonise the ground where it thrives. From late spring to late summer, the plant forms a beautiful mass of vibrant green vegetation, topped with numerous spikes of yellow flowers. It is perfect for quickly forming a good ground cover. As well as being ornamental, it is also known for its medicinal uses and dyeing properties. This very useful plant grows in moist to marshy areas, but it can be a bit too invasive near a body of water.

Lysimachia vulgaris belongs to the Primulaceae family. Native to lowland areas of Europe and Asia, it has become abundantly naturalised in North America where it is considered invasive in several states. It is a vigorous rhizomatous and stoloniferous perennial, capable of spreading up to 4 to 5m (13 to 16ft) in all directions, at least. Its above-ground vegetation is deciduous in winter, emerging from the ground in spring and drying up at the end of the season. From its long underground, aerial, or aquatic stems, new upright stems emerge every spring, reaching an average height of 75cm (30in). These stems bear large, slightly hairy, lanceolate, almost petioleless bright green leaves. Flowering occurs from May to September, depending on the climate. Pyramid-shaped inflorescences form at the end of the leafy stems, bearing small clusters of bright yellow flowers. Each flower, carried on a long pedicel, has a small tubular base that widens into 5 lobes and measures 2 to 3cm (1in) in diameter. This plant can become quite invasive in heavy, wet soils.

Common loosestrife thrives in sunny or semi-shaded exposures, particularly in clayey and waterlogged soils, which are slightly acidic to limestone. It will be easier to contain and highly appreciated for its beauty in a bed where the soil remains consistently moist throughout the year. It is especially suitable for the banks of large natural ponds. In this context, it can be associated with resistant plants that it won't smother: horsetails, purple loosestrife, rushes, persicarias, and meadowsweet, for example. Together, these plants will form a natural area beneficial for biodiversity.

Common loosestrife has long been known for its medicinal properties: its leaves were traditionally used to treat wounds and bruises. Our ancestors also used it for combating internal or external ulcers, and intestinal disorders.

The flowers contain a yellow pigment used for dyeing wool.