Urenia

Urenia is a genus of flowering plants in the family Lamiaceae, commonly known as the false mermaidweed or simply mermaidweed. These plants are native to eastern North America, typically found in wet or moist habitats such as swamps, marshes, and along the edges of streams and ponds. The genus contains a single species, Urenia terrestris, though it is sometimes classified under the genus Hydrastylus.

Urenia plants are herbaceous perennials with creeping rhizomes. They are characterized by their small, inconspicuous flowers that appear in the leaf axils. The flowers are typically white and have a somewhat star-like appearance. The leaves are usually simple, ovate to lanceolate, and can be either smooth or toothed along the margins. Urenia terrestris is a low-growing plant, often forming mats along the ground.

The plant's common name, mermaidweed, is thought to derive from its preference for aquatic or semi-aquatic environments. Historically, some indigenous peoples may have used parts of the plant for medicinal purposes, though detailed information is limited. Today, Urenia is primarily of interest to botanists and ecologists studying wetland flora. Its presence is often an indicator of healthy, undisturbed wet habitats. The genus is relatively small and not widely cultivated, remaining a less common but characteristic component of its native ecosystems.