| Noun | 1. | genus Arnica - large genus of herbs of north temperate and Arctic regions asterid dicot genus - genus of more or less advanced dicotyledonous herbs and some trees and shrubs aster family, Asteraceae, Compositae, family Asteraceae, family Compositae - plants with heads composed of many florets: aster; daisy; dandelion; goldenrod; marigold; lettuces; ragweed; sunflower; thistle; zinnia arnica - any of various rhizomatous usually perennial plants of the genus Arnica Arnica cordifolia, heartleaf arnica - wildflower with heart-shaped leaves and broad yellow flower heads; of alpine areas west of the Rockies from Alaska to southern California Arnica montana - herb of pasture and open woodland throughout most of Europe and western Asia having orange-yellow daisylike flower heads that when dried are used as a stimulant and to treat bruises and swellings |