Arnica

Taxobox
name = Arnica

---

image_width = 225px
image_caption = Chamisso Arnica ("Arnica chamissonis")
regnum = Plantae
divisio = Magnoliophyta
classis = Magnoliopsida
ordo = Asterales
familia = Asteraceae
subfamilia = Asteroideae
tribus = Heliantheae
subtribus = Madiinae
genus = "Arnica"
genus_authority = L.
subdivision_ranks = Species
subdivision = See text.

Arnica ("Ár-ni-ca") is a genus with about 30 perennial, herbaceous species, belonging to the sunflower family (Asteraceae). The genus name "Arnica" may be derived from the Latin "arna", "lamb", in reference to the soft, hairy leaves.

This circumboreal and montane genus occurs mostly in the temperate regions of western North America, while two are native to Eurasia ("A. angustifolia" and "A. montana").

"Arnica" used to be included in the tribe Senecioneae, because it has a 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. Lately Arnica was placed in an unresolved clade together with Madiinae, Eupatorieae, Heliantheae s.s. and Pectidinae.

Several species, such as "Arnica montana" and "Arnica chamissonis", contain helenalin, which is a sesquiterpene lactone that is a major ingredient in anti-inflammatory preparations (mostly against bruises).

"Arnica" species are used as food plants by the larvae of some Lepidoptera species including "Bucculatrix arnicella".

Characteristics

They 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 long ray 9 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.

The seed-like fruit has a pappus of plumose, white or pale tan bristles. The entire plant has a strong and distinct pine-sage odor when the leaves of mature plants are rubbed or bruised.

Uses and toxicity

"Arnica montana" has long been used medicinally, [ [http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=102636 Arnica in Flora of North America @ efloras.org ] ] ["Clonal propagation of Arnica montana L., a medicinal plant"Authors: Buthuc-Keul, A.; Deliu, C.Source: In Vitro Cellular and Development Biology - Plant, Volume 37, Number 5, September 2001 , pp. 581-585(5)Publisher: Springer] It 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. [ [http://www.ces.ncsu.edu/depts/hort/consumer/poison/Arnicmo.htm Poisonous Plants: Arnica montana ] ] [Edward Rudzki, Zdzisława Grzywa (1977) "Dermatitis from Arnica montana" Contact Dermatitis 3 (5), 281–281. doi:10.1111/j.1600-0536.1977.tb03682.x] The roots contain derivatives of thymol,cite journal |author=Weremczuk-Jezyna I, Kisiel W, Wysokińska H |title=Thymol derivatives from hairy roots of Arnica montana |journal=Plant Cell Rep. |volume=25 |issue=9 |pages=993–6 |year=2006 |pmid=16586074 |doi=10.1007/s00299-006-0157-y |accessdate=2008-01-27] which are used as fungicides and preservatives and may have some anti-inflammatory effect.cite journal |author=Braga PC, Dal Sasso M, Culici M, Bianchi T, Bordoni L, Marabini L |title=Anti-inflammatory activity of thymol: inhibitory effect on the release of human neutrophil elastase |journal=Pharmacology |volume=77 |issue=3 |pages=130–6 |year=2006 |pmid=16763380 |doi=10.1159/000093790 |url=http://content.karger.com/produktedb/produkte.asp?typ=fulltext&file=PHA2006077003130 |accessdate=2008-01-27]

Arnica is currently used in liniment and ointment preparations used for strains, sprains, and bruises. Commercial arnica preparations are frequently used by professional athletes. The thymol derivatives concentrated in the plants roots have been clinically shown to be effective vasodilators of subcutaneous blood capillaries. Arnica preparations used topically have been demonstrated to act as an anti-inflammatory and assist normal healing processes by facilitating transport of blood and fluid accumulations through a dilating action of subcutaneous blood capillaries. If ingested, the toxin helenalin produces severe gastroenteritis, and internal bleeding of the digestive tract if enough material is ingested. [Edible and Medicinal Plants of the West, Gregory L. Tilford, ISBN 0-87842-359-1]

pecies

*"Arnica acaulis" (Walt.) B.S.P. -- Common Leopardbane
*"Arnica alpina" (L.) Olin -- Alpine Arnica (synonym of "Arnica angustifolia" subsp. "alpina")
*"Arnica amplexicaulis" Nutt. -- Clasping Arnica, Streambank Arnica (synonym of "Arnica lanceolata" subsp. "amplexicaulis")
*"Arnica angustifolia" Vahl -- Narrowleaf Arnica
**"Arnica angustifolia" subsp. "alpina" (L.) I. K. Ferguson
**"Arnica angustifolia" subsp. "tomentosa" Downie & Denford
*"Arnica cernua" T.J. Howell -- Serpentine Arnica
*"Arnica chamissonis" Less. -- Chamisso Arnica
**"Arnica chamissonis" subsp. "foliosa" (Nutt.) Maguire
*"Arnica cordifolia" Hook. -- Heart-leaf Leopardbane, Heartleaf Arnica
*"Arnica dealbata" Baldwin (formerly Whitneya dealbata)
*"Arnica discoidea" Benth. -- Rayless Arnica
*"Arnica X diversifolia" Greene (pro sp.) -- Curtis Churchmouse Threeawn, Rayless Arnica, Sticky Arnica
*"Arnica frigida" C.A. Mey. ex Iljin -- Snow Arnica (synonym of A"rnica griscomii" subsp. "frigida")
*"Arnica fulgens" Pursh -- Foothill Arnica, Orange Arnica, Shining Leopardbane
*"Arnica x gracilis" Rydb. -- Smallhead Arnica (a natural hybrid between "A. latifolia" and "A. cordifolia")
*"Arnica griscomii" Fernald
**"Arnica griscomii" subsp. "frigida" (C. A. Mey. ex Iljin) S. J. Wolf
**"Arnica griscomii" subsp. "griscomii" Downie & Denford
*"Arnica lanceolata" Nutt. -- Arnica, Lanceleaf Arnica
**"Arnica lanceolata" subsp. "amplexicaulis" (Nutt.) Gruezo & Denford
**"Arnica lanceolata" subsp. "lanceolata" Gruezo & Denford
*"Arnica latifolia" Bong. -- Broadleaf Arnica
*"Arnica lessingii" (Torr. & Gray) Greene -- Nodding Arnica
**"Arnica lessingii" subsp. "lessengii"
**"Arnica lessingii" subsp. "norbergii" Hult. & Maguire
*"Arnica lonchophylla" Greene -- Longleaf Arnica
**"Arnica lonchophylla" subsp. "arnoglossa" (Greene) Maguire
**"Arnica lonchophylla" subsp. "lonchophylla"
*"Arnica longifolia" D.C. Eat. -- Longleaf Arnica, Spearleaf Arnica
*"Arnica louiseana" Farr -- Lake Louise Arnica
*"Arnica mallotopus" (formerly Mallotopus japonicus)
*"Arnica mollis" Hook. -- hairy arnica, wooly arnica
*"Arnica montana" L. -- Mountain Arnica
*"Arnica nevadensis" Gray -- Nevada Arnica
*"Arnica ovata" Greene
*"Arnica parryi" Gray -- Nodding Arnica, Parry's Arnica
*"Arnica rydbergii" Greene -- Rydberg Arnica, Rydberg's Arnica, Subalpine Arnica
*"Arnica sachalinensis" (Regel) A. Gray
*"Arnica sororia" Greene -- Twin Arnica
*"Arnica spathulata" Greene -- Klamath Arnica
*"Arnica unalaschcensis" Less. -- Alaska Arnica
*"Arnica venosa" Hall -- Shasta County Arnica
*"Arnica viscosa" Gray -- Mt. Shasta Arnica

References

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*cite journal|author=Wolf, S.J. & K.E. Denford|year= 1984|title= Taxonomy of Arnica (Compositae) subgenus Austromontana|journal= Rhodora Journal of the New England Botanical Club|volume= 86|issue=847|pages= 239–309
* 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
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