Urtica dioica

This concept follows the broader treatment of Urtica dioica by FNA (1997) and Kartesz (1994), who include U. dioica ssp. gracilis and U. dioica ssp. holosericea (= U. gracilis ssp. holosericea) in U. dioica. Henning et al. (2014) exclude ssp. gracilis and ssp. holosericea from U. dioica and instead treat them as subspecies of U. gracilis.

Urtica dioica is a wide-ranging perennial herb found in alluvial woods, margins of deciduous or mixed woodlands, riparian woods, herbaceous swamps and fens, grasslands, shrublands, dune margins, ditches, and fencerows. It occurs throughout temperate and boreal areas of North America and Eurasia; in North America, this species is common in the western and northeastern United States, Canada (except Arctic regions), and Alaska, and is occasional or waif in the southeastern United States. There are thousands of occurrences worldwide, which potentially face threats from development, water diversion, invasive species, and other threats in some places. Little is known about trends, but with a large range extent and large number of occurrences, abundant habitat, and broad habitat preferences, this species is considered secure.

Urtica dioica is found throughout temperate and boreal areas of North America and Eurasia (FNA 1997). It is also introduced in South America and New Zealand (GBIF 2025). In North America, this species is common in the western and northeastern United States, Canada (except Arctic regions), and Alaska, and is occasional or waif in the southeastern United States (GBIF 2025, Weakley and the Southeastern Flora Team 2025). Native range extent was estimated using herbarium specimens, photo-based observations, and NatureServe Network occurrence data collected between 1994 and 2025 (GBIF 2025, iNaturalist 2025, NatureServe 2025, RARECAT 2025, SEINet 2025). See individual entries for distribution details about the three subspecies.

By applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1994 and 2025, it is estimated that there are thousands of occurrences worldwide (GBIF 2025, iNaturalist 2025, NatureServe 2025, RARECAT 2025, SEINet 2025).

Although threats are not widely documented, Urtica dioica is potentially threatened by development, water diversion, invasive species, and other threats in some places. However, their overall impact is likely negligible given the species' broad range, large number of occurrences, tolerance of light disturbance, and affinity for typically abundant habitats.