Lysimachia

Yellow pimpernel

Lysimachia punctata spotted loosestrife MN 2007

Lysimachia ciliata mosbo6

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Lysimachia borealis mosbo6

Lysimachia is a genus of flowering plants in the family Primulaceae. The genus is named after Lysimachus, a king of ancient Sicily who is said to have calmed a mad ox by giving it a member of this plant. The common names for this genus include loosestrife and yellow pimpernel, among others. Lysimachia species are found worldwide, from temperate to tropical regions, and they are especially diverse in Asia and North America.

Description

Lysimachia species are herbaceous, with some being annuals and others perennials. They can vary greatly in size, from small, low-growing plants to taller species that can reach several feet in height. The leaves are typically opposite or whorled, with a simple, entire margin. The flowers of Lysimachia are usually yellow, but can also be white, red, or pink, and they often have a five-petaled, star-like shape. The fruit is a capsule that splits open when ripe, releasing the small seeds.

Ecology

Lysimachia species are found in a variety of habitats, including wetlands, forests, grasslands, and areas of disturbed soil. They are important plants for many pollinators, including bees, butterflies, and other insects. Some species of Lysimachia are known to form dense colonies, which can outcompete other plant species and dominate large areas. This characteristic has led to some species being considered invasive in parts of their range.

Cultivation and Uses

Many Lysimachia species are cultivated for their attractive flowers and are used in gardens and landscaping. They are particularly valued for their ability to thrive in moist or wet soils, making them suitable for water gardens, pond margins, and other damp locations. Some species, such as Lysimachia nummularia (creeping Jenny), are popular as ground covers due to their fast growth and dense foliage.

In addition to their ornamental value, some Lysimachia species have been used in traditional medicine. However, the medicinal properties and uses vary widely among species and regions, and scientific evidence supporting these uses is limited.

Selected Species

• Lysimachia nummularia – Creeping Jenny
• Lysimachia clethroides – Gooseneck loosestrife
• Lysimachia vulgaris – Yellow loosestrife
• Lysimachia punctata – Dotted loosestrife
• Lysimachia terrestris – Swamp candles

Conservation

The conservation status of Lysimachia species varies. While many species are common and not considered at risk, others are rare and face threats from habitat loss, invasive species, and changes in land use. Conservation efforts for these plants include habitat protection, cultivation in botanical gardens, and research into their ecology and biology.