''Arnica longifolia'' is a

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

n species of

arnica ''Arnica'' is a genus of perennial plant, perennial, herbaceous plants in the sunflower family (Asteraceae). The genus name ''Arnica'' may be derived from the Greek language, Greek ''wikt:arni, arni'', "lamb", in reference to the plants' soft, h ...

in the sunflower family, known by the common names seep-spring arnica,Great Basin Wildflowers, Laird R. Blackwell, 2006, Morris Book Publishing LLC., longleaf arnica and spearleaf arnica. This flowering perennial is native to the forests of western Canada ( British Columbia + Alberta) and the western United States ( Rocky Mountains, Cascades,

Coast Ranges The Pacific Coast Ranges (officially gazetted as the Pacific Mountain System in the United States) are the series of mountain ranges that stretch along the West Coast of North America from Alaska south to Northern and Central Mexico. Although the ...

Sierra Nevada The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily ...

and other mountains of California, Oregon, Washington, Idaho, Nevada, Utah, Wyoming, Colorado, and Montana). ''Arnica longifolia'' is a rhizomatous plant forming large bunching patches of groundcover in moist, cool areas. The foliage is rough, mint-green, and sometimes sticky with glandular secretions. The stems are erect and bear daisylike

flower heads A pseudanthium (Greek for "false flower"; ) is an inflorescence that resembles a flower. The word is sometimes used for other structures that are neither a true flower nor a true inflorescence. Examples of pseudanthia include flower heads, compos ...

with deep yellow ray florets and yellow to reddish or orange disc florets. The fruit is a reddish

achene An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and indehiscent (they do not ope ...

with a small pappus.Flora of North America Vol. 21 Page 374 Spearleaf arnica ''Arnica longifolia'' D. C. Eaton in S. Watson, Botany (Fortieth Parallel). 186. 1871.
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References

External links

Jepson Manual TreatmentUnited States Department of Agriculture Plants Profile
* longifolia Flora of the Northwestern United States Plants described in 1871 Flora of the Southwestern United States Flora of Western Canada Flora without expected TNC conservation status {{Madieae-stub