[[File:Arnica chamissonis0.jpg|thumb|right|''Arnica montana '']]
'''Arnica''' is a genus of [[perennialplant]], herbaceous plants in the sunflower family (Asteraceae). The genus name Arnica may be derived from the Greek arni, "lamb", in reference to the plants' soft, hairy leaves. Arnica is also known by the names Mountain Tobacco and, confusingly, Leopard's bane and Wolfsbane—two names that it shares with the entirely unrelated genus Aconitum.
Several species, such as Arnica montana and A.chamissonis, contain helenalin, a sesquiterpene lactone that is a major ingredient in anti-inflammatory preparations (used mostly for bruises).
*Arnica species are used as food plants by the larvae of some Lepidoptera species including Bucculatrix arnicella.
*Commercial Arnica homeopathic preparations are frequently used by professional athletes.[5] According to The Memorial Sloan-Kettering Cancer Center, "A few clinical trials suggest benefits of topical arnica for osteoarthritis; and for affecting significant reduction of bruising compared to placebo or low concentration vitamin K ointments.<ref name="uses"/>
==common name==