Arnica montana is a perennial herb that is native to the mountainous pastures and woodlands of continental Europe.
It is known by many common names including Leopard's bane, Mountain tobacco, Wolfbane (See also Aconitum napellus), and Mountain arnica. There are approximately thirty members of the Arnica genus, and it is a member of Asteraceae (Sunflower family). Therefore, It is closely related to species such as the Aster and Daisy.
Arnica is herbaceous and often grown for medicinal purposes where its roots and flowers are used to make a tincture or gel that is applied exogenously in the treatments of wounds, sprains, hair-growth, and chilblains. It is noteworthy that the plant contains many toxins, such as helenalin, and should therefore not be taken internally, or applied to broken skin, as it may lead to internal bleeding if ingested.
Arnica montana photograph by Peter Stevens
Active ingredients in the plant include thymol, which is found in the roots and has fungicidal properties, and the above-mentioned helenalin, which has anti-inflammatory properties. Scientific tests have shown that a 50% solution of Arnica gel applied topically has a similar effect to a 5% ibuprofen gel when used for the treatment of osteoarthritis in the hands. However, repeated use of Arnica montana can lead to skin irritation.
Arnica montana are perennials that reach heights of 30 to 60 cm (12–24 inches) and has a spread of about 20 cm (8 inches). They have a rosette of ovoid green basal leaves, and tall stems that have a few opposite bright green downy leaves that are toothed and aromatic.
The stems carry a single yellow/orange flower from mid-spring to the end of summer. The flowers are about 5 to 6 cm (2 inches) in diameter and have 10–15 ray florets, and a multitude of disc florets.
Mountain arnica plant picture by Frank Vassen