Arnica montana | |
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1897 illustration | |
Scientific classification | |
Kingdom: | Plantae |
(unranked): | Angiosperms |
(unranked): | Eudicots |
(unranked): | Asterids |
Order: | Asterales |
Family: | Asteraceae |
Genus: | Arnica |
Species: | A. montana |
Binomial name | |
Arnica montana L. |
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Synonyms | |
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Arnica montana, sometimes referred to as wolf's bane, has also been called leopard's bane, mountain tobacco and mountain arnica, is a European flowering plant in the sunflower family. It is noted for its large yellow flower head.
Arnica montana is a flowering plant about 18–60 cm (7.1–23.6 in) tall aromatic fragrant, perennial herb. Its basal green ovate-cilitate leaves with rounded tips are bright coloured and level to the ground. In addition, they are somewhat downy on their upper surface, veined and aggregated in rosettes. By contrast, the upper leaves are opposed, spear-shaped and smaller which is an exception within the Asteraceae. The chromosome number is 2n=38.
The flowering season is between May and August (Central Europe). The hairy flowers are composed of yellow disc florets in the center and orange-yellow ray florets at the external part. The achenes have a one-piece rough pappus which opens in dry conditions.Arnica montana is a hemicryptophyte, which helps the plant to survive the extreme overwintering condition of its habitat. In addition, Arnica forms rhizomes, which grow in a two-year cycle: the rosette part grows at its front while its tail is slowly dying.
Arnica montana is widespread across most of Europe. It is absent from the British Isles and the Italian and Balkan peninsulas and Slovakia. In addition, it is considered extinct in Hungary and Lithuania.Arnica montana grows in nutrient-poor siliceous meadows or clay soils. It mostly grows on alpine meadows and up to nearly 3,000 m (9,800 ft). In more upland regions, it may also be found on nutrient-poor moors and heaths. However Arnica does not grow on lime soil, thus it is an extremely reliable bioindicator for nutrient poor and acidic soils. It is rare overall, but may be locally abundant. It is becoming rarer, particularly in the north of its distribution, largely due to increasingly intensive agriculture and commercial wild-crafting. Nevertheless, it is cultivated on a large scale in Estonia.
The main constituents of Arnica montana are essential oils, fatty acids, thymol, pseudoguaianolide sesquiterpene lactones and flavanone glycosides. Pseudoguaianolide sesquiterpenes constitute 0.2-0.8 % of the flower head of Arnica montana. They are the toxin helenalin and their fatty esters.2,5-Dimethoxy-p-cymene and thymol methyl ether are the primary components of essential oils from both the plant's roots and rhizomes.