Note: Do not rely on this information. It is very old.
Arnica
Arnica, a genus of plants belonging to the order Composite, the tincture of one species of which, A. montana, a native of Central Europe, has a powerful action in exciting the circulation beneath the skin without blistering, and is, therefore, useful for bruises. Internally it is an acrid narcotic. The flower is a dark golden yellow, and blossoms from about June to August.