Lysimachia punctata aka Dotted Loosestrife

Lysimachia punctata is a herbaceous perennial in the primrose family. Gardeners know it as yellow or dotted loosestrife. Sources differ on the limits of its native range. Kew lists Crimea, the Caucasus, and Türkiye. Horticultural sources also include central and southern Europe and Asia. Garden escapes now grow across parts of the United States and Canada. They grow in damp meadows, ditches, roadsides, and stream banks.

The plant forms upright clumps that spread through underground rhizomes. Garden plants reach about 3 feet [0.91 metres] tall. Some reach 4 feet [1.22 metres]. Clumps span roughly 1–1.5 feet [0.30–0.46 metres], before spreading into colonies. The firm, green stems bear fine hairs and lack scent. Green leaves have an oval to lance-shaped outline. Their hairs give them a soft, velvety feel. Leaves reach 0.25 feet [0.076 metres] long. Most grow in rings of three or four around stems. Some leaves grow in opposite pairs instead.

Yellow flowers appear in groups where leaves meet the stems. These groups form spikes along the upper stems. Each cup-shaped flower has five petals and an orange-red centre. Fine hairs also cover the petals. Flowers measure about 0.08 feet [0.025 metres] across. Missouri Botanical Garden and NC State give May through September. Chicago Botanic Garden lists flowering through October. The fruit is a small red to burgundy capsule. The flowers draw butterflies and other pollinators.

Grow this plant in sun or partial shade. Rich soil that drains well but stays moist suits it best. It accepts clay, loam, and sand, across a broad pH range. It also tolerates wet soil. Afternoon shade helps in the St. Louis area. Dry or lean soil can curb its spread. Such soil does not give the best growth. Sources place it in USDA zones 4–8. Gardeners can raise new plants from seed or by division.

Use it in wild gardens, cottage gardens, or distant borders. It can also cover ground near ponds and streams. Keep it apart from valued perennials that it might crowd. Rhizomes and self-sown seedlings can create large colonies. Check its spread to prevent unwanted growth into nearby beds. Rust and leaf spots can occur. Missouri Botanical Garden reports no major insect or disease problems. The supplied sources give no evidence on edibility or toxicity.