arnica montana arnica montana arnica montana, also known as wolf's bane, leopard's bane, mountain tobacco and mountain arnica, is a moderately toxic european flowering plant in the daisy family asteraceae. it is noted for its large yellow flower head. the names "wolf's bane" and "leopard's bane" are also used for another plant, aconitum, which is extremely poisonous. arnica montana 1897 illustration scientific classification kingdom: plantae clade: tracheophytes clade: angiosperms clade: eudicots clade: asterids order: asterales family: asteraceae genus: arnica species: a. montana binomial name arnica montanal. synonyms doronicum montanum lam. doronicum oppositifolium lam. arnica helvetica loudon arnica petiolata schur arnica plantaginifolia gilib. arnica lowii holm cineraria cernua thore arnica montana is used as an herbal medicine for analgesic and anti-inflammatory purposes, but there is insufficient high-quality clinical evidence for such effects, and it is toxic when taken internally or applied to injured skin. description arnica montana arnica montana is a flowering plant about 18–60 cm (7.1–23.6 in) tall aromatic fragrant, herbaceous perennial. its basal green ovate 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. taxonomy the latin specific epithet montana refers to mountains or coming from mountains. distribution and habitat distribution map of arnica montana. arnica montana is widespread across most of europe. it is absent from the celtic isles and the italian and balkan peninsulas. 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 wildcrafting (foraging). nevertheless, it is cultivated on a large scale in estonia. chemical constituents chemical structure of helenalin 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. the quality and chemical constitution of the plant substance arnicae flos can be monitored by near-infrared spectroscopy. cultivation arnica montana fruits and seeds arnica montana: photo taken at botanical garden in erlangen, germany. arnica montana is propagated from seed. generally, 20% of seeds do not germinate. for large scale planting, it is recommended to raise plants first in a nursery and then to transplant them in the field. seeds sprout in 14–20 days but germination rate depends highly on the seed quality. planting density for arnica montana is of 20 plants/m2 such that the maximum yield density will be achieved in the second flowering season. while arnica montana has high exigencies of soil quality, analyses should be done before any fertilizer input. the flowers are harvested when fully developed and dried without their bract nor receptacles. the roots can be harvested in autumn and dried as well after being carefully washed. arnica montana is sometimes grown in herb gardens. use in herbal medicine