|Arnica montana |
L. 1753 not Boehm. 1760
This Circumboreal and montane (subalpine) genus occurs mostly in the temperate regions of western North America, with a few species native to the Arctic regions of northern Eurasia and North America.
Arnica used to be included in the tribe Senecioneae because it has a flower or pappus of fine bristles. This was soon questioned and Nordenstam (1977) placed it tentatively in tribe Heliantheae s.l. This arrangement also became uncertain because of the sesquiterpene lactone chemistry in certain species. Recently Arnica was placed in an unresolved clade together with Madiinae, Eupatorieae, Heliantheae s.s. and Pectidinae.
Arnica is also known by the names Mountain Tobacco and, somewhat confusingly, Leopard's bane and Wolfsbane—two names that it shares with the entirely unrelated genus Aconitum.
Arnica plants have a deep-rooted, erect stem that is usually unbranched. Their downy opposite leaves are borne towards the apex of the stem. The ovoid, leathery basal leaves are arranged in a rosette.
They show large yellow or orange flowers, 6–8 cm wide with 10–15 cm long ray florets and numerous disc florets. The phyllaries (a bract under the flowerhead) has long spreading hairs. Each phyllary is associated with a ray floret. Species of Arnica, with an involucre (a circle of bracts arranged surrounding the flower head) arranged in two rows, have only their outer phyllaries associated with ray florets. The flowers have a slight aromatic smell. If taken in the wrong dose it can be very dangerous.
Commercial Arnica preparations are frequently used by professional athletes. According to The Memorial Sloan-Kettering Cancer Center, "A few clinical trials suggest benefits of topical arnica for osteoarthritis; and for affecting significant reduction of bruising compared to placebo or low concentration vitamin K ointments. However, a small study reported that topical arnica actually increased pain 24 hours after calf exercises." 
Arnica montana contains the toxin helenalin, which can be poisonous if large amounts of the plant are eaten, and contact with the plant can also cause skin irritation. If enough of the material is ingested, the toxin helenalin produces severe gastroenteritis, and internal bleeding of the digestive tract. Homeopathic preparations of Arnica 24X dilution or more contain no active ingredient and are, therefore, non-toxic.
Homeopathic preparations of Arnica are widely marketed and used. In the UK, the Medicines and Healthcare products Regulatory Agency has registered the product for sprains and bruising under the National Rules for Homoeopathic Products (2006). These rules allow claims of efficacy for these conditions to be made on the packaging in the absence of similar evidence to that required for conventional medicines under the Medicines Act 1968 and 1971. A systematic review of clinical trials showed that homeopathic Arnica was no more effective than a placebo. In some quarters, the fact that homeopathic Arnica has been the subject of published clinical trials at all has drawn criticism grounded on the allegation that the basic premise of the high dilutions used in homeopathy would be inherently flawed.
- Arnica acaulis —Common Leopardbane - eastern US from Alabama to New Jersey
- Arnica angustifolia —Narrowleaf Arnica - Canada (from British Columbia to Quebec), US (Montana, Idaho, Wyoming, Colorado); Russia, Scandinavia
- Arnica cernua —Serpentine Arnica - California, Oregon
- Arnica chamissonis —Chamisso Arnica - US West of Rockies incl Alaska; Canada (British Columbia to Quebec plus Yukon + Northwest Territories)
- Arnica cordifolia —Heart-leaf Leopardbane, Heartleaf Arnica - US West of Rockies plus Alaska + Michigan; Canada (from British Columbia to Quebec plus Yukon + Northwest Territories)
- Arnica dealbata - California
- Arnica discoidea Rayless Arnica - California, Oregon, Nevada, Washington
- Arnica fulgens Foothill Arnica, Orange Arnica, Shining Leopardbane - USA= West of Rockies plus Michigan; Canada (from British Columbia to Manitoba)
- Arnica gracilis —Smallhead Arnica (A. latifolia x A. cordifolia) - US (Montana, Idaho, Wyoming, Colorado, Oregon, Washington); British Columbia, Alberta, Northwest Territories
- Arnica griscomii - Russia, Canada, Alaska
- Arnica intermedia - eastern Russia (Yakutskiya, Khabarovsk, Magadan)
- Arnica lanceolata —Arnica, Lanceleaf Arnica - US West of Rockies plus Alaska, Maine New Hampshire, Vermont, New York State; Canada (British Columbia, Quebec, New Brunswick)
- Arnica latifolia —Broadleaf Arnica - western US, western Canada
- Arnica lessingii —Nodding Arnica - Kamchatka, Alaska, Yukon, Northwest Territories, British Columbia
- Arnica lonchophylla —Longleaf Arnica - most of Canada; Alaska, Montana, Minnesota, South Dakota
- Arnica longifolia —Longleaf Arnica, Spearleaf Arnica - US West of Rockies, British Columbia, Alberta
- Arnica louiseana —Lake Louise Arnica - British Columbia, Alberta
- Arnica mallotopus - Honshu Island in Japan
- Arnica mollis —hairy arnica, wooly arnica - - US West of Rockies plus Alaska, New Hampshire + Vermont; Canada (from British Columbia to Quebec plus Yukon + Northwest Territories)
- Arnica montana — Mountain Arnica - most of Europe plus Greenland; naturalized in India
- Arnica nevadensis —Nevada Arnica - California, Oregon, Nevada, Washington
- Arnica ovata - British Columbia Alberta, Yukon, US West of Rockies
- Arnica parryi —Nodding Arnica, Parry's Arnica - British Columbia, Alberta, Yukon, US West of Rockies
- Arnica porsildiorum - Kamchatka, Yukon Northwest Territories
- Arnica rydbergii —Rydberg Arnica, Rydberg's Arnica, Subalpine Arnica - British Columbia, Alberta, northwestern USA
- Arnica sachalinensis - Hokkaido, Sakhalin, Kuril, Irkutsk
- Arnica sororia —Twin Arnica - British Columbia, Alberta, Saskatchewan, US West of Rockies
- Arnica spathulata —Klamath Arnica - California Oregon
- Arnica unalaschcensis —Alaska Arnica - Hokkaido, Honshu, Kamchatka, Sakhalin, Kuril, Alaska
- Arnica venosa —Shasta County Arnica - California
- Arnica viscosa —Mt. Shasta Arnica - California, Oregon
- 1897 illustration from Franz Eugen Köhler, Köhler's Medizinal-Pflanzen
- Altervista Flora Italiana, Arnica, Arnica montana L. includes photos and European distribution maps
- Flora of North America, Arnica Linnaeus
- Buthuc-Keul, A. L.; Deliu, C. (September 2001). "Clonal propagation of Arnica montana L., a medicinal plant". In Vitro Cellular and Development Biology - Plant. Society for In Vitro Biology. 37 (5): 581–585. doi:10.1007/s11627-001-0102-2.
- Jenna Sumara (2006). "Arnica: the natural alternative for treating sore muscles". The Final Sprint. Retrieved 2008-12-11.
- "Arnica". Cancer Care - Integrative Medicine. The Sloan-Kettering Cancer Center. 2013-07-18. Retrieved 2014-01-03.
- M. Wolfa, C. Tamaschkeb, W. Mayerc, M. Heger (2003). "Wirksamkeit von Arnica bei Varizenoperation: Ergebnisse einer randomisierten, doppelblinden, Placebo-kontrollierten Pilot-Studie". Forschende Komplementärmedizin und Klassische Naturheilkunde. 10: 242–247. doi:10.1159/000074778.
- "Poisonous Plants: Arnica montana". Ces.ncsu.edu. Retrieved 2009-12-22.
- Edward Rudzki; Zdzisława Grzywa (May 1977). "Dermatitis from Arnica montana". Contact Dermatitis. 3 (5): 281–2. doi:10.1111/j.1600-0536.1977.tb03682.x. PMID 145351.
- Gregory L. Tilford. Edible and Medicinal Plants of the West. ISBN 0-87842-359-1.
- "Dynamization and Dilution". Creighton University Department of Pharmacology. Retrieved 2007-10-09.
- Vaughan, John Griffith; Patricia Ann Judd; David Bellamy (2003). The Oxford Book of Health Foods. Oxford University Press. p. 59. ISBN 0-19-850459-4.
- Youngson, RM (April 1997). "Randomized trial of homeopathic Arnica". Journal of the Royal Society of Medicine. 90 (4): 239–240. PMC . PMID 9155774.
- "Arnica registered by medicines regulator". Telegraph. 16 May 2009.
- E. Ernst; M. H. Pittler (November 1998). "Efficacy of Homeopathic Arnica:A Systematic Review of Placebo-Controlled Clinical Trials". Archives of Surgery. 133 (11): 1187–1190. doi:10.1001/archsurg.133.11.1187. PMID 9820349.
- The Plant List search for Arnica
- Baldwin, B. G. (1999). "New combinations in Californian Arnica and Monolopia". Novon. Missouri Botanical Garden Press. 9 (4): 460–461. doi:10.2307/3392142. JSTOR 3392142.
- Lyss, G., T. J. Schmidt, H. L. Pahl, and I. Merfort (1999). "Anti-inflammatory activity of Arnica tincture (DAB 1998) using the transcription factor NF-kappaB as molecular target". Pharmaceutical and Pharmacological Letters. 9: 5–8.
- Maguire, B.; Gilly, C. L (1943). "A monograph of the genus Arnica (Senecioneae, Compositae)". Brittonia. New York Botanical Garden Press. 4 (3): 386–510. doi:10.2307/2804900. JSTOR 2804900.
- Nordenstam, B. 1977 Senecioneae and Liabeae—systematic review. In V. H. Heywood, J. B. Harborne, and B. L. Turner [eds.], The biology and chemistry of the Compositae, vol. II, 799–830. Academic Press, London, UK
- Stevinson, C., Devaraj, V. S., Fountain-Barber, A., Hawkins, S. and Ernst, E. (2003). "Homeopathic arnica for prevention of pain and bruising: randomized placebo-controlled trial in hand surgery". Journal of the Royal Society of Medicine. 96 (2): 60–65. doi:10.1258/jrsm.96.2.60.
- Wolf, S.J.; K.E. Denford (1984). "Taxonomy of Arnica (Compositae) subgenus Austromontana". Rhodora. 86 (847): 239–309.
|Look up arnica in Wiktionary, the free dictionary.|
|Wikisource has the text of the 1911 Encyclopædia Britannica article Arnica.|