Burke: Arnica latifolia vs. Arnica sororia

	Arnica latifolia	Arnica sororia
	broad-leaved arnica, mountain arnica, daffodil leopardbane	bunch arnica, twin arnica, twin leopardbane
Habit	Perennial, 1-6 dm. tall, glandular at least above.	Perennial from slender rhizomes, the slender stems 2-6 dm. tall
Leaves	Broad, long-petiolate basal leaves sometimes on short separate stalks; cauline leaves 2-4 pairs, lance-elliptic or broader, rarely cordate, more or less toothed, 2-14 cm. long and 1-8 cm. wide, the middle ones larger than the lower.	Basal leaves petiolate, the blades lanceolate, 3-12 cm. long and 1-2.5 cm. wide; cauline leaves 2-4 pair, the lower ones with short petioles, reduced upward.
Flowers	Heads 1-several; involucre 7-18 mm. high, more or less glandular; pappus white, barbellate.	Heads few; involucres 10-15 mm high, the bracts narrow, tapering from the base, pointed; disk corollas with stalked glands; pappus white
Fruits	Achenes glabrous, at least toward the base.

	Arnica latifolia	Arnica sororia
Identification notes	The similar Arnica cordifolia has larger heads, frequently solitary; its leaves and achenes are pubescent.	The similar Arnica fulgens has long, woolly brown hairs in the axils of the lower leaves; A sororia usually has no axillary hairs; if any are present, they are white.
Flowering time	June-August	May-July
Habitat	Common in forest openings and meadows, and open, rocky areas from middle to high elevations in the mountains.	From low elevation prairies and grasslands to coniferous forest openings at middle elevations.
Distribution	Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains. [WildflowerSearch map] [BONAP county map]	Occurring east of the Cascades crest in Washington; British Columbia to California, east to Alberta, Montana, and Wyoming. [WildflowerSearch map] [BONAP county map]
Origin	Native	Native
Conservation status	Not of concern	Not of concern
Sibling taxa	A. chamissonis, A. cordifolia, A. discoidea, A. fulgens, A. gracilis, A. lanceolata, A. longifolia, A. mollis, A. nevadensis, A. ovata, A. parryi, A. rydbergii, A. sororia	A. chamissonis, A. cordifolia, A. discoidea, A. fulgens, A. gracilis, A. lanceolata, A. latifolia, A. longifolia, A. mollis, A. nevadensis, A. ovata, A. parryi, A. rydbergii
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria, Turner Photog. 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, Turner Photog. WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Arnica sororia

broad-leaved arnica, mountain arnica, daffodil leopardbane

bunch arnica, twin arnica, twin leopardbane

Habit

Perennial, 1-6 dm. tall, glandular at least above.

Perennial from slender rhizomes, the slender stems 2-6 dm. tall

Leaves

Broad, long-petiolate basal leaves sometimes on short separate stalks; cauline leaves 2-4 pairs, lance-elliptic or broader, rarely cordate, more or less toothed, 2-14 cm. long and 1-8 cm. wide, the middle ones larger than the lower.

Basal leaves petiolate, the blades lanceolate, 3-12 cm. long and 1-2.5 cm. wide;

cauline leaves 2-4 pair, the lower ones with short petioles, reduced upward.

Flowers

Heads 1-several;

involucre 7-18 mm. high, more or less glandular;

pappus white, barbellate.

Heads few;

involucres 10-15 mm high, the bracts narrow, tapering from the base, pointed; disk corollas with stalked glands;

pappus white

Fruits

Achenes glabrous, at least toward the base.

Arnica latifolia

Arnica sororia

Identification notes

The similar Arnica cordifolia has larger heads, frequently solitary; its leaves and achenes are pubescent.

The similar Arnica fulgens has long, woolly brown hairs in the axils of the lower leaves; A sororia usually has no axillary hairs; if any are present, they are white.

Flowering time

June-August

May-July

Habitat

Common in forest openings and meadows, and open, rocky areas from middle to high elevations in the mountains.

From low elevation prairies and grasslands to coniferous forest openings at middle elevations.

Distribution