Lysimachia nummularia - Creeping Jenny

Lysimachia nummularia, also known as Moneywort, is very different from its larger cousins but just as vigorous. It has a spreading habit and small leaves that resemble coins. It blooms all summer, illuminating shady corners with its intense yellow cup-shaped flowers. It is a perennial of wet forests, with its prostrate stems rooting in moist, sunny, or partially shaded soils, quickly forming a good ground cover. This plant is ideal in moist to marshy areas and at the edges of basins. It can tolerate occasional trampling.

Lysimachia nummularia belongs to the Primulaceae family. It is native to large parts of Europe, as well as Turkey and the Caucasus, and has become widely naturalised in North America. It is a vigorous creeping perennial, quickly forming a dense mat, up to a maximum thickness of 8cm (3in). It spreads and covers the ground over a significant area, at least 1m². It forms prostrate stems that root in contact with moist soils, covered with small round and opposite leaves, measuring 2cm (1in). The medium green leaves are deciduous. Flowering occurs from June to August, in the form of 25mm (1in) diameter bright yellow cups. These solitary flowers are borne on short peduncles in the axils of the leaves. This plant spreads by stolons and can become invasive.

Lysimachia nummularia thrives in cool, sunny, or partially shaded soil. It is particularly suitable for pond edges, where it quickly colonises until its leaves float on the water. But it is also an excellent plant for cool understory areas. In this use, it can be combined with resilient plants that it won't smother: creeping bugle, foamflower, periwinkle, Corsican mint, Pratia pedunculata, Irish moss, Saxifraga x arendsii (decipiens), and Cranesbill geranium. Together, these plants will form a flowery carpet that follows the contours of the terrain. It is stunning in a cool rockery, cascading between stones.

Lysimachia nummularia has recognised medicinal properties.