[Cal-IPC] Impact on native species: Marrubium vulgare (white horehound) is a perennial shrub/forb/herb (family Lamiaceae). This plant is found heavily populating disturbed places throughout California in grasslands scrub and riparian areas. It has mostly minor impact on native species. (link added by Mary Ann Machi)

[Wikipedia] Europe,Africa, Asia Native: Marrubium vulgare (white horehound or common horehound) is a flowering plant in the mint family (Lamiaceae), native to Europe, northern Africa, and southwestern and central Asia. It is also widely naturalized in many places, including most of North and South America. (link added by Mary Ann Machi)