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diverse arnica, leaf arnica, sticky arnica, sticky-leaf arnica

nodding arnica, Parry's arnica

Habit Plants 10–50 cm. Plants 15–50(–60) cm.
Stems

(forming clumps) simple or branched among heads.

simple or branched among heads.

Leaves

2–3(–4) pairs (basal 1–2 pairs usually withered by flowering, petiolate, petioles broadly winged, blades round-ovate, relatively small; sterile rosettes lacking), mostly cauline; petiolate (at least middle pair, petioles broadly to narrowly winged);

blades broadly deltate to ovate, 4–8 × 2–6 cm (middle pair largest), margins irregularly denticulate to coarsely dentate-serrate, apices acute, faces puberulent (hairs minute) and stipitate-glandular.

(2–)3–4 pairs, basal and cauline (basal usually withered by flowering, petiolate or subsessile, blades ovate or nearly round to oblong-ovate, much smaller than cauline; sterile rosettes often present, proximal cauline often crowded toward stems bases); petiolate;

blades broadly to narrowly lanceolate, oblong-ovate, ovate-lanceolate, or round, 4–22 × 1–6 cm, (bases obtuse or cuneate to truncate) margins usually entire, sometimes sparsely denticulate, faces scantily to moderately pilose (hairs white), adaxial sparsely stipitate-glandular (distal cauline leaves sessile, extremely reduced, nearly linear to narrowly elliptic-lanceolate).

Involucres

usually narrowly turbinate, rarely narrowly campanulate.

turbinate to narrowly campanulate.

Ray florets

8–16, yellow.

usually 0 (sometimes peripheral florets pistillate; corollas yellow, laminae rudimentary).

Disc florets

corollas yellow;

anthers yellow.

20–50;

corollas yellow (1 or more lobes sometimes expanded, giving appearance of laminae);

anthers yellow.

Phyllaries

9–20, linear to narrowly lanceolate.

8–20, linear to narrowly lanceolate.

Heads

1–3(–5).

(1–)3–9(–14; often nodding in bud).

Cypselae

brown to black, 5–7 mm, sparsely to moderately pilose and stipitate-glandular;

pappi stramineous to tawny, bristles subplumose.

brown to black, 4–7 mm, glabrous or sparsely stipitate-glandular to densely hirsute;

pappi usually stramineous, rarely tawny, bristles barbellate to ± subplumose.

2n

= 57, 76.

= 38, 57, 76.

Arnica ovata

Arnica parryi

Phenology Flowering Jul–Sep. Flowering May–Sep.
Habitat Moist meadows and conifer forests, stream banks, late snow-melt areas, montane to subalpine Open conifer forests to alpine meadows
Elevation 200–3600 m (700–11800 ft) 500–3800 m (1600–12500 ft)
Distribution
from FNA
AK; CA; CO; ID; MT; OR; UT; WA; WY; AB; BC; YT
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; CO; ID; MT; NV; OR; UT; WA; WY; AB; BC; YT
[WildflowerSearch map]
[BONAP county map]
Source FNA vol. 21, p. 372. FNA vol. 21, p. 373.
Parent taxa Asteraceae > tribe Heliantheae > subtribe Chaenactidinae > Arnica Asteraceae > tribe Heliantheae > subtribe Chaenactidinae > Arnica
Sibling taxa
A. acaulis, A. angustifolia, A. cernua, A. chamissonis, A. cordifolia, A. dealbata, A. discoidea, A. fulgens, A. gracilis, A. griscomii, A. lanceolata, A. latifolia, A. lessingii, A. lonchophylla, A. longifolia, A. louiseana, A. mollis, A. nevadensis, A. parryi, A. rydbergii, A. sororia, A. spathulata, A. unalaschcensis, A. venosa, A. viscosa
A. acaulis, A. angustifolia, A. cernua, A. chamissonis, A. cordifolia, A. dealbata, A. discoidea, A. fulgens, A. gracilis, A. griscomii, A. lanceolata, A. latifolia, A. lessingii, A. lonchophylla, A. longifolia, A. louiseana, A. mollis, A. nevadensis, A. ovata, A. rydbergii, A. sororia, A. spathulata, A. unalaschcensis, A. venosa, A. viscosa
Synonyms A. diversifolia, A. latifolia var. viscidula A. angustifolia subsp. eradiata, A. parryi subsp. sonnei, A. parryi var. sonnei
Name authority Greene: Pittonia 4: 161. (1900) A. Gray: Amer. Naturalist 8: 213. (1874)
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