Arnica montana, also referred to as Arnica, mountain tobacco and mountain arnica, is a moderately toxic ethnobotanical European flowering plant in the sunflower family. It is noted for its large yellow flower head.
Arnica montana is widespread across most of Europe. It is absent from the British Isles and the Italian and Balkan peninsulas and Slovakia. In addition, it is considered extinct in Hungary and Lithuania.
Arnica montana grows in nutrient-poor siliceous meadows or clay soils. It mostly grows on alpine meadows and up to nearly 3,000 m (9,800 ft). In more upland regions, it may also be found on nutrient-poor moors and heaths. Arnica does not grow on lime soil, thus it is an extremely reliable bioindicator for nutrient poor and acidic soils.