Ciliate Loosestrife

Ciliate loosestrife (Lysimachia ciliata) is a rhizomatous perennial herb in the family Primulaceae, native to eastern and central North America, where it grows in moist to wet habitats including stream banks, lake margins, floodplain forests, meadows, and roadside ditches. It has been introduced to Europe, where it has naturalized and occasionally become invasive in riparian and wetland habitats in several countries. The plant produces erect stems typically 60–100 centimeters tall bearing opposite or whorled leaves with characteristic fringed (ciliate) petioles, which distinguish it from related species. The flowers are yellow with five petals reflexed backward, resembling other loosestrifes. Lysimachia ciliata blooms in summer and attracts specialist pollinators including Macropis bees, which collect floral oils from the flowers of Lysimachia species. The species is classified as Not Evaluated by the IUCN. It is common and widespread across its native North American range, from British Columbia and Quebec south to Florida and Texas. Cultivated varieties with bronze-purple foliage, such as 'Firecracker', are popular garden plants. In Europe, wild or garden-escaped populations can colonize disturbed wet habitats, raising ecological concerns about competition with native riparian flora. The generic placement in Primulaceae follows recent molecular phylogenetic revisions that merged the former Lysimachiaceae into the primrose family.