Arnica, Mountain arnica
Arnica montana

Family: Asteraceae or Compositae

What it is like

Arnica montana is a PERENNIAL growing to 0.3 m (1ft) by 0.2 m (0ft 8in). See above for USDA hardiness. It is hardy to UK zone 6 and is not frost tender. It is in flower in July. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees, flies, Lepidoptera (Moths & Butterflies). The plant is self-fertile. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils, prefers well-drained soil and can grow in nutritionally poor soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in very acid soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Height (m): 0.3

Where it is found

Calcareous soils in mountain pastures. Found especially on granite or siliceous soils in the Alps, up to 2500 metres. Pasture and open woodland, usually on poorer acid soils.

C. Europe.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 0

Medicine

Rating: 3

Arnica has a long history of herbal use, especially as an external treatment for bruises and sprains - it is an ingredient of a number of proprietary preparations. Internally, it has been used in the treatment of heart complaints and as a booster for the immune system. Arnica increases local blood supply and accelerates healing, it is anti-inflammatory and increases the rate of absorption of internal bleeding. Generally the plant is nowadays only recommended for internal use as a homeopathic medicine, principally for treating shock, injury and pain. If used as a decoction or tincture it stimulates the circulation and is valuable in the treatment of angina and a weak or failing heart, but it can be toxic even at quite low doses and so is rarely used this way. The flowers are the part most commonly used, they are harvested when fully open and dried - the receptacles are sometimes removed since these are liable to be attacked by insects. The root is also used, it is harvested after the leaves have died down in the autumn and dried for later use. The whole plant is antiecchymotic, antiphlogistic, nervine, sternutatory, vulnerary. Although a very valuable remedy, it should be used with caution. It has been known to cause contact dermatitis when used externally and collapse when taken internally. Only take it internally under the supervision of a qualified practitioner. The freshly crushed flowers cause sneezing if inhaled. The leaves have also been smoked as a tobacco, though it is unclear whether this was for medicinal reasons The whole plant, harvested when in flower, is used in homeopathic remedies. It is especially useful in the treatment of traumatic injuries, sores and bruises. The homeopathic dose has also been used effectively in the treatment of epilepsy and seasickness, and it might be of use as a hair growth stimulant. The German Commission E Monographs, a therapeutic guide to herbal medicine, approve Arnica montana for fever and colds, inflammation of the skin, cough/bronchitis, inflammation of the mouth and pharynx, rheumatism, common cold, blunt injuries, tendency to infection. The essential oil has to be diluted before being used externally .

Antiecchymotic: Prevents or treats bruising.

Antiphlogistic: Reduces inflammation.

Antirheumatic: Treats rheumatism.

Epilepsy: Used in the treatment of Epilepsy - a disorder in which nerve cell activity in the brain is disturbed, causing seizures.

Nervine: Stimulates and calms the nerves.

Sternutatory: Promotes sneezing and nasal discharges.

Vulnerary: Promotes the healing of wounds.

Other

Rating:

How it is grown

Prefers a moist, well-drained humus rich soil, preferably lime-free. One report says that it is often found in calcareous soils in the wild. Tolerates a pH in the range 5.8 to 7.6. Prefers a mixture of sand, loam and peat. Prefers a position in full sun. Succeeds in light woodland and in a rock garden or border. Plants are hardy to about -25°c. This species is declining in the wild, probably because of over-collection as a medicinal herb. It may become extinct in part of its range.

Propagating it: Seed - best sown as soon as it is ripe in pots outdoors. Sow stored seed in early spring in a cold frame. A period of cold stratification is helpful. The fresh seed can germinate in 3 - 4 weeks at 13°c according to one report, though it can be slow, difficult and erratic and take 2 years to germinate. Prick out the seedlings into individual pots when they are large enough to handle and plant them out into their permanent positions in the following spring. Division in spring.

Best place to grow: Woodland Garden Sunny Edge; Dappled Shade; Cultivated Beds;

Habit: Perennial

Hardiness: 5-9

Growth:

Soil: Light (sandy), medium, heavy (clay)

Shade: Semi-shade, no shade

Moisture: Moist

Things to keep in mind

Deadly in large quantities. The whole plant is toxic and should only be used for external applications to unbroken skin. Alcoholic extracts of arnica can cause toxic effects on the heart and raise blood pressure .

Its other names

Local names

Synonyms

Arnica montana var. alpina L. Arnica montana var. angustifolia