Lysimachia tenella, commonly known as Slender Yellow Loosestrife or Bog Pimpernel, is a perennial herb native to damp habitats such as fens, bogs, wet meadows, and stream margins across Europe and Asia. It thrives on moisture-retentive, clay-rich soils and is often seen in the semi-shaded conditions of forest clearings. This plant typically grows to a modest height of 10-30 cm, with a creeping habit that allows it to form low carpets of foliage. The leaves are small, lanceolate, and opposite, creating a delicate texture. From late spring to mid-summer, it produces small, star-shaped yellow flowers that are subtly attractive rather than showy.

Slender Yellow Loosestrife is valued for its ability to thrive in wet conditions and is often used in water gardens, bog gardens, and around ponds. It is also suitable for naturalistic plantings and wildlife gardens, as it provides nectar for pollinators. In cultivation, it requires consistently moist soil and can tolerate both full sun and part shade, making it versatile for various garden settings. While it is not particularly prone to diseases, it can suffer from root rot if drainage is poor. Gardeners should be aware that in some conditions, it may spread vigorously and require control to prevent it from becoming invasive.CC BY-SA 4.0