General Wellness | Massage Therapy What is Arnica? ByDr. Gregg Baron May 5, 2010May 5, 2010 Arnica (Arnica Montana) is a flower indigenous to mountainous areas of Europe and North America. Arnica can grow up to two feet, and is topped by a single yellow flower. It has for centuries been used to treat sprains, strains, bruises and other bone or muscle trauma. Arnica has been successful in treating hematomas, dislocations, contusions, swelling, muscle injuries and joint stiffness.