Volume 1: 1771 Edition of the Encyclopedia Britannica!
Arnica, in botany, a genus of the syngenesia polygamia superflua class. The receptacle of the arnica is naked; it has a simple pappus; and the filaments are five, without anterae. There are seven species of arnica, all natives of Ethiopia, except the montana and scorpioides, which are found in Germany. The leaves and root of the arnica have been esteemed a specific in resolving coagulated blood; but their operation is so violent, that they are but rarely used.