Arnica montana, commonly known as arnica, is a perennial herb of the Asteraceae family. It grows mainly in mountainous regions of Europe and North America and is known for its medicinal properties, mainly as a topical anti-inflammatory. It is a flowering plant, aromatic, herbaceous and perennial. The flowering period is between May and August (Central Europe). It is distinguished by its large yellow flower. Arnica montana is used as a medicinal plant for analgesic and anti-inflammatory purposes.

Botanical description:

• Family: Asteraceae
• Genus: Arnica
• Kind: Arnica montana
• Flowers: Its flowers are yellow or orange, have a strong scent and bloom in summer.
• Leaves: Its leaves are oval and usually appear in pairs.

Cultivation
The flowers are collected when fully grown and dried without their stems. The roots can be harvested in the fall and dried after being carefully washed. Arnica Montana is also cultivated in botanical gardens and pots.

Naming & Classification

The genus name Arnica is derived from the Greek arni, "lamb", in reference to the plants' soft, hairy leaves. The Latin specific epithet montana refers to mountains or those originating from mountains. It is a moderately toxic European flowering plant in the daisy family Asteraceae.

Arnica Montana is widespread throughout most of Europe. It can grow even in poor, clayey soils lacking nutrients. It also grows in alpine meadows and at an altitude of 3,000 meters.

Chemical composition The main components of Arnica montana are essential oils, fatty acids, thymol, pseudoguaianolide sesquiterpene lactones and flavanone glycosides. pseudoguaianolide sesquiterpenes (0.2-0.8% of Arnica montana flower heads), the toxin elenalin and their fatty esters.

Use in herbal medicine
Historically, Arnica montana has been used as an herbal medicine for centuries. The traditional uses of the plant are similar to those of willow bark and are used for analgesic and anti-inflammatory purposes. Specifically:

• Pain and inflammation

• In fractures and bone regeneration

• In injuries, bruises and sprains

• In Homeopathy 

Clinical trials of Arnica Montana have yielded mixed results:
When used topically in gel with concentration 50%, the Arnica was found to be about as effective as a 5% Ibuprofen gel. for the treatment of symptoms of osteoarthritis of the hands.

Toxicity

Arnica should not be consumed internally or used orally. The U.S. Food and Drug Administration has classified Arnica montana as an unsafe herb due to its toxicity. Arnica contains the toxin helenalin, which can be poisonous if large amounts of the plant are consumed or if used in concentrated form in small amounts.. It should not be taken orally or applied to open wounds where absorption may occur. Arnica irritates mucous membranes and can cause stomach pain, diarrhea, and vomiting. 

Consuming Arnica montana can cause severe gastroenteritis, internal bleeding of the digestive tract, elevated liver enzymes (which may indicate liver inflammation), nervousness, accelerated heart rate, muscle weakness, and death if ingested in large amounts.

Use as directed by your doctor or pharmacist.