The European A. montana probably killed the Swiss herbalist Konrad von Gesner (1516-1565) who took some orally and died about an hour later. All arnica species are licensed only for external use in the UK and USA but internal use is allowed in Germany. Numerous Arnica species exist in the USA (A. chamissonis not mentioned here) and used by many tribes. Arnica fulgens used on wounds and sore muscles. A. acaulis drunk for back pain by the Catawba.

Milspaugh, C.E. (1974) American Medical Plants

Used for bruises by Native Americans.

Hutchens, Alma A (1991) Indian Herbology of North America

Named for Adelbert von Chamisso (30 January 1781 – 21 August 1838) was a German poet and botanist, travelled around the world, discovered Eschscholzia californica. Poet. Custodian Berlin Botanic Garden.

wikipedia

The European A. montana probably killed the Swiss herbalist Konrad von Gesner (1516-1565) who took some orally and died about an hour later. All arnica species are licensed only for external use.

Northern America