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sticky arnica

slender arnica

Habit Plants 1.5–4 dm; rhizomatous. Plants 1–3 dm; rhizomatous.
Stems

single or branched, usually glandular-puberulent, sometimes glabrate proximally or sparsely scabrous-pilose.

usually much branched, minutely glandular-puberulent, sometimes glabrate proximally.

Basal leaves

usually much reduced, withering early; round-ovate;

petioles broadly winged.

sometimes reduced and withering early, usually in separate sterile rosettes.

Cauline leaves

2–3(4) pairs;

distal 1–2 pairs reduced and bract-like;

blades ovate to lanceolate, 2–8 cm, bases truncate or attenuate;

margins denticulate or serrate-dentate, rarely entire;

veins branching laterally;

tips acute or obtuse;

surfaces glabrous to glandular-puberulent, often gland-dotted; short-petiolate or sessile.

2–3 pairs;

blades triangular to ovate or lanceolate, 2–6 cm, bases truncate to rounded or attenuate;

margins entire to denticulate to serrate-dentate;

veins branching laterally;

tips acute;

surfaces glandular or spiculate, usually petiolate, sometimes sessile.

Peduncles

glandular-puberulent.

glabrate or minutely glandular-puberulent.

Involucres

turbinate, 10–15 mm.

turbinate-campanulate, 6–12 mm.

Ray florets

8–15;

rays 10–20 mm, yellow.

5–12;

rays 10–20 mm, yellow.

Disc florets

15–40;

corollas 7–10 mm, yellow.

10–25;

corollas 4–6 mm, yellow.

Phyllaries

lanceolate to elliptic or linear;

tips acute;

surfaces pilose and stipitate-glandular.

elliptic-lanceolate or oblanceolate;

tips acute;

surfaces glabrate to strigose or glandular-puberulent.

Fruits

columnar-fusiform, 5–6.5 mm, brown or blackish, hispidulous;

pappus bristles 7–10 mm; brownish, subplumose.

columnar-fusiform, 4.5–7 mm; black; hirsute or spiculate-glandular;

pappus bristles 5–7 mm, white, barbellate.

Heads

radiate.

radiate.

2n

=57, 76.

=57, 76.

Arnica diversifolia

Arnica gracilis

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

Open pine forests, grasslands, bogs, subalpine talus, cliffs, ridges. Flowering Jul–Sep. 1700–3000 m. BW, Casc. CA, ID, WA; north to AK, northeast to MT, southeast to UT. Native.

Open pine forests, meadows, cliffs, rocky slopes and ridges. Flowering Jun–Aug. 1400–2800 m. BW, Casc. ID, WA; north to Northwest Territories, northeast to MT, east to WY, southeast to CO. Native.

Source Flora of Oregon, volume 2, page 184
Kenton Chambers
Flora of Oregon, volume 2, page 184
Kenton Chambers
Sibling taxa
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. parryi, A. rydbergii, A. sororia, A. spathulata, A. viscosa
A. cernua, A. chamissonis, A. cordifolia, A. discoidea, A. diversifolia, A. fulgens, A. lanceolata, A. latifolia, A. longifolia, A. mollis, A. nevadensis, A. parryi, A. rydbergii, A. sororia, A. spathulata, A. viscosa
Synonyms Arnica ovata Arnica latifolia var. gracilis
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