The photo at
right shows a flower head of hairy arnica (Arnica mollis).
Chamisso Arnica, Leafy Arnica, Meadow Arnica, Narrowleaf Arnica, Silvery Arnica, Leafy Leapordbane: Arnica chamissonis (Synonyms: Arnica chamissonis ssp. chamissonis, Arnica chamissonis ssp. foliosa, Arnica chamissonis ssp. incana, Arnica chamissonis var. andina, Arnica chamissonis var. chamissonis, Arnica chamissonis var. foliosa, Arnica chamissonis var. incana, Arnica chamissonis var. interior, Arnica chamissonis var. maguirei) - 5-12 pairs of stem leaves. Tips of involucral bracts blunt to slightly acute, bearing a tuft of whitish hairs. Flower heads with 8-15 rays measuring 1-2 cm long.
Heartleaf Arnica, Heart-leaf Arnica, Heart-leaf Leopardbane: Arnica cordifolia (Synonyms: Arnica cordifolia var. cordifolia, Arnica cordifolia var. pumila) - 2-4 pairs of stem leaves. Flower heads of ray flowers surrounding a central disk. Blades of basal and stem leaves heart-shaped. Involucre with many whitish hairs.
Rayless Arnica, Rayless Leopardbane: Arnica discoidea (Synonyms: Arnica discoidea var. eradiata, Arnica grayi, Arnica parviflora ssp. alata, Arnica parviflora ssp. parviflora, Arnica parviflora) - Heads completely discoid. No ray flowers present. 2-4 pairs of stem leaves. Flower heads not nodding prior to bloom.
Hillside Arnica, Orange Arnica, Shining Leopardbane: Arnica fulgens -
Mountain Arnica, Slender Arnica, Slender Leopardbane: Arnica gracilis (Synonym: Arnica latifolia var. gracilis) - 2-4 pairs of stem leaves. Flower heads of ray flowers surrounding a central disk.Flower heads of ray flowers surrounding a central disk. Basal leaves present, usually not with heart-shaped blades. Stem leaves not heart-shaped. Involucres glabrous or with few whitish hairs. (Similar to mt. arnica.)
Clasping Arnica, Streambank Arnica, Streambank Leopardbane: Arnica lanceolata ssp. prima (Synonyms:Arnica amplexicaulis, Arnica amplexicaulis ssp. amplexicaulis, Arnica amplexicaulis var. amplexicaulis, Arnica amplexicaulis var. piperi, Arnica amplexifolia ssp. prima) -
Broad-leaf Arnica, Broad-leaved Arnica, Daffodil Leopardbane, Longleaf Arnica, Mountain Arnica, Spearleaf Arnica, Seep Spring Arnica, Spear-leaf Leopardbane: Arnica latifolia (Synonym: Arnica latifolia var. latifolia) - 2-4 pairs of stem leaves. Flower heads of ray flowers surrounding a central disk. Basal leaves present, usually not with heart-shaped blades. Stem leaves not heart-shaped. Involucre glabrous or with few whitish hairs. (Similar to slender arnica.)
Longleaf Arnica, Seep Spring Arnica, Spearleaf Arnica, Spear-leaf Arnica: Arnica longifolia (Synonym: Arnica longifolia ssp. myriadenia) - 5-12 pairs of stem leaves. Tips of involucral bracts acute, lacking a tuft of whitish hairs at the tip.
Hairy Arnica: Arnica mollis - 2-4 pairs of stem leaves. Flower heads of ray flowers surrounding a central disk. Basal leaves lacking, the lowest stem leaves usually the largest.. Flower heads broad. Pappus of featherlike, light brown bristles.
Nodding Arnica, Parry's Arnica: Arnica parryi (Synonyms: Arnica angustifolia ssp. eradiata, Arnica parryi ssp. parryi, Arnica parryi ssp. sonnei, Arnica parryi var. parryi, Arnica parryi var. sonnei) - 2-4 pairs of stem leaves. Flower heads discoid, generally lacking ray flowers. Flower heads nodding prior to bloom.
Rydberg's Arnica, Subalpine Arnica, Subalpine Leopardbane: Arnica rydbergii - 2-4 pairs of stem leaves. Flower heads of ray flowers surrounding a central disk.