Arnica griscomii ssp. frigida is member of the aster family (Asteraceae) with yellow flowering heads and broad, opposite leaves. A perennial herb with erect rarely branched stems, plants grow from a rhizome up to 30 cm tall, but are usually are much shorter. Frigid arnica is found along river floodplains, in meadows, rocky slopes and alpine tundra. The basal leaves are lanceolate to oblanceolate, 3-5 veined, and 1-8 cm long, simple, with entire margins, more or less densely hairy and occasionally glandular. There are 1-4 pairs of opposite stem leaves, up to 10 cm long, and toothed. There are 1-3 flowering heads per plant. The bases of the involucres have long yellow hairs, and are 10-18 mm long. The ray and tube flowers are yellow; the rays (petals) are oblong and notched at the apex. In fruit, each flower matures into a narrow achene (dry fruit), topped with a tuft of white hairs, the pappus. Frigid arnica is most similar to A. lessingii, which also has one nodding flowering head, but in that species the pappus is brown and the anthers are black to dark purple. Arnica angustifolia is taller, has upright heads and narrow leaves.
This species flowers from late June to August depending on aspect and elevation.
This species is likely insect pollinated, but its reproductive biology has not been studied. Plants are monoecious. The seeds have a tuft of hairs to aid in wind dispersal. Plants may also reproduce vegetatively.
The flavonoid profile of Arnica griscomii is likely to be of value in identifying unglaciated refugia in Alaska (Downie and Denford 1986). Refer to Arnica angustifolia for medicinal uses.
Snow arnica is an amphi-Beringian endemic species, occurring in the Russian Far East, Alaska, British Columbia, Yukon Territory and Northwest Territories. This species occurs across most of Alaska except the Aleutian chain. In Denali, snow arnica occurs more frequently on the north side of the Alaska Range than to the south.