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broadleaf arnica, mountain arnica

Parry's arnica

Habit Plants 1–5 dm; strongly rhizomatous. Plants 1.5–7 dm; rhizomatous.
Stems

usually simple, sometimes branched, glabrous to puberulent or villous.

simple to much branched, villous, stipitate-glandular distally.

Basal leaves

withering early, usually in separate sterile rosettes, petiolate.

withered by flowering, often in separate sterile rosettes, petiolate or subsessile.

Cauline leaves

2–4 pairs;

blades ovate, lanceolate, or elliptic, 1.5–14 cm, bases rounded to attenuate, rarely truncate or cordate;

margins entire to denticulate, dentate, or serrate;

veins branching laterally;

tips acute;

surfaces glabrous to puberulent or strigose;

adaxial surfaces sometimes densely and minutely strigillose; most sessile; lower pair sometimes subsessile.

2–4 pairs; lowermost crowded near stem bases; upper pairs much reduced;

blades ovate to lanceolate or linear-elliptic, 2–10 cm, bases rounded or attenuate;

margins entire or denticulate;

veins branching laterally;

tips acute;

surfaces villous-tomentose, sparsely stipitate-glandular or gland-dotted adaxially; lowermost long-petiolate; upper sessile.

Peduncles

glabrate or villous, sometimes glandular-puberulent at apex.

stipitate-glandular.

Involucres

cylindric to campanulate or hemispheric, 8–15 mm.

campanulate, 10–15 mm.

Ray florets

5–15;

rays 10–28 mm, yellow.

0 or obscure.

Disc florets

20–90;

corollas 6–10 mm, yellow.

20–60;

corollas 8–10 mm, yellow.

Phyllaries

broadly or narrowly lanceolate to oblanceolate, elliptic, or linear;

tips acute or acuminate;

surfaces glabrous to pilose or villous, sometimes tomentulose or glandular-puberulent at bases.

narrowly oblanceolate to elliptic or linear;

tips acute or acuminate;

surfaces stipitate-glandular, sometimes also hispid.

Fruits

columnar-fusiform, 5–9 mm, dark brown, glabrous to glandular-puberulent;

pappus bristles 5–7 mm, white, barbellate.

columnar-fusiform, 4–6 mm, dark brown or blackish, glabrous or hispid;

pappus bristles 7–10 mm; straw-colored, barbellate.

Heads

radiate.

discoid or rarely obscurely radiate, nodding in bud.

2n

=38, 76.

=38, 57, 76.

Arnica latifolia

Arnica parryi

Distribution
[WildflowerSearch map]
[BONAP county map]
[WildflowerSearch map]
[BONAP county map]
Discussion

Coniferous forests, meadows, shrublands, cliffs, rocky talus, clearcuts, roadsides. Flowering May–Sep. 300–2300 m. BW, Casc, CR, ECas, Owy, Sisk. CA, ID, WA; north to AK, northeast to Alberta, east to WY, southeast to NM. Native.

Coniferous forests, meadows, ridges. Flowering Jun–Sep. 1200–2700 m. BR, BW, Casc, ECas, Sisk. CA, ID, NV, WA; north to Yukon, northeast to Alberta, east to WY, southeast to CO. Native.

Source Flora of Oregon, volume 2, page 185
Kenton Chambers
Flora of Oregon, volume 2, page 186
Kenton Chambers
Sibling taxa
A. cernua, A. chamissonis, A. cordifolia, A. discoidea, A. diversifolia, A. fulgens, A. gracilis, A. lanceolata, A. longifolia, A. mollis, A. nevadensis, A. parryi, A. rydbergii, A. sororia, A. spathulata, A. viscosa
A. cernua, A. chamissonis, A. cordifolia, A. discoidea, A. diversifolia, A. fulgens, A. gracilis, A. lanceolata, A. latifolia, A. longifolia, A. mollis, A. nevadensis, A. rydbergii, A. sororia, A. spathulata, A. viscosa
Synonyms Arnica latifolia var. latifolia Arnica parryi var. parryi, Arnica parryi var. sonnei
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