Streambank Arnica: Arnica amplexicaulis var. amplexicaulis - Stem leaves number 5-12. Leaves generally toothed, usually measuring 5-12 mm long and 1.2-4 cm wide. Flower heads have a yellow central disc surrounded by 8 to 14 yellow ray flowers. Leaves narrower, generally less than 4 cm wide.

Streambank Arnica: Arnica amplexicaulis var. piperi - Stem leaves number 5-12. Leaves generally toothed. Flower heads have a yellow central disc surrounded by 8 to 14 yellow ray flowers. Leaves broader, measuring up to 6 cm wide.

Heart-leaf Arnica, Heart-leaf Leopardbane: Arnica cordifolia (Synonyms: Arnica cordifolia var. cordifolia, Arnica cordifolia var. pumila) - Stem leaves generally number 2-3 pairs, the blades toothed and heart-shaped. Flower heads have a yellow central disc surrounded by 8 to 12 yellow ray flowers. Tips of ray flowers pointed.

Rayless Arnica: Arnica discoidea - Stem leaves number 2-4 pairs. The blades are ovate to somewhat heart-shaped, measuring 4-8 cm long and 1.5-5 cm wide. Flower heads entirely discoid, the rays lacking.

Hillside Arnica: Arnica fulgens - Stem leaves number 2-4 pairs, the narrow blades about 3-10 times longer than wide. Flower heads broad with 10-23 rays (each 1.5-2.5 cm long).

Mountain Arnica: Arnica latifolia - Stem leaves number 2-4 pairs, the broad leaves about 1.5-2 times longer than wide (up to 8 cm wide). The lower leaves are rarely heart-shaped. A showy wildflower with opposite, hear-shaped to lance-shaped leaves. The stem and basal leaves are similar in size. The flower heads are yellow, with both rays and disk flowers.

Rydberg's Arnica: Arnica rydgergii - Stem leaves number 2-4 pairs, the narrow blades about 3-10 times longer than wide. Flower heads small with 7-10 rays (each 1-2 cm long).