Arnica Gel is a genus with about 30 perennial, herbaceous species, belonging to the sunflower family (Asteraceae). The genus name Arnica may be derived from the Latin arna, "lamb", in reference to the soft, hairy leaves. Arnica usually refers to Arnica montana. In the North American colonies the flowers are used in preference to the rhizome. In countries where Arnica is indigenous, it has long been a popular remedy for relief of bruises, stiffness, and muscle soreness in herbal medicine.