OregonFlora: Arnica dealbata vs. Arnica fulgens

	Arnica dealbata	Arnica fulgens
		hillside arnica, orange arnica
Habit		Plants 1–5 dm; rhizomatous.
Stems		simple, densely glandular-puberulent, setulose distally.
Basal leaves		well developed; petioles winged.
Cauline leaves		1–3 pairs; much reduced distally; blades oblanceolate or lance-elliptic to linear, 2.5–8 cm; proximal bases woolly-tufted; margins entire; veins parallel from bases; tips acute; surfaces minutely stipitate-glandular, often gland-dotted, sessile.
Peduncles		densely glandular-puberulent.
Involucres		hemispheric, 10–16 mm.
Ray florets		8–16; rays 12–30 mm, orange-yellow.
Disc florets		15–60; corollas 7–10 mm, yellow, with glandular and non-glandular trichomes.
Phyllaries		elliptic-oblong to broadly lanceolate; tips acute or obtuse; surfaces densely stipitate-glandular, setulose.
Fruits		columnar-fusiform, 4–7 mm, gray or blackish, densely hirsute; pappus bristles 5–7 mm, white or straw-colored, barbellate.
Heads		radiate.
2n		=38, 57.

	Arnica dealbata	Arnica fulgens
Distribution	[WildflowerSearch map] [BONAP county map]	[WildflowerSearch map] [BONAP county map]
Discussion		Moist meadows, open woodlands. Flowering Jun–Aug. 1600–2800 m. BR, BW, Casc, ECas. CA, NV, ID, WA; north to British Columbia, northeast to Manitoba, east to SD, southeast to NM. Native. The disc corolla pubescence traits differing between Arnica fulgens and A. sororia may be difficult to see except under high magnification.
Source		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. gracilis, A. lanceolata, A. latifolia, A. longifolia, A. mollis, A. nevadensis, A. parryi, A. rydbergii, A. sororia, A. spathulata, A. viscosa
Web links	Local floras: CA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Arnica dealbata

Arnica fulgens

hillside arnica, orange arnica

Habit

Plants 1–5 dm; rhizomatous.

Stems

simple, densely glandular-puberulent, setulose distally.

Basal leaves

well developed;

petioles winged.

Cauline leaves

1–3 pairs; much reduced distally;

blades oblanceolate or lance-elliptic to linear, 2.5–8 cm;

proximal bases woolly-tufted;

margins entire;

veins parallel from bases;

tips acute;

surfaces minutely stipitate-glandular, often gland-dotted, sessile.

Peduncles

densely glandular-puberulent.

Involucres

hemispheric, 10–16 mm.

Ray florets

8–16;

rays 12–30 mm, orange-yellow.

Disc florets

15–60;

corollas 7–10 mm, yellow, with glandular and non-glandular trichomes.

Phyllaries

elliptic-oblong to broadly lanceolate;

tips acute or obtuse;

surfaces densely stipitate-glandular, setulose.

Fruits

columnar-fusiform, 4–7 mm, gray or blackish, densely hirsute;

pappus bristles 5–7 mm, white or straw-colored, barbellate.

Heads

radiate.

=38, 57.

Arnica dealbata

Arnica fulgens

Distribution

[WildflowerSearch map]

[BONAP county map]

[WildflowerSearch map]

[BONAP county map]

Discussion

Moist meadows, open woodlands. Flowering Jun–Aug. 1600–2800 m. BR, BW, Casc, ECas. CA, NV, ID, WA; north to British Columbia, northeast to Manitoba, east to SD, southeast to NM. Native.

The disc corolla pubescence traits differing between Arnica fulgens and A. sororia may be difficult to see except under high magnification.

Source

Flora of Oregon, volume 2, page 184
Kenton Chambers

Sibling taxa