Erigeron grandiflorus is a plant of the high mountains, growing at or above the treeline. In favourable locations the flower stalks can reach a height of 10 inches, but on less good ground they are just 2 to 4 inches tall. The green leaves are usually spatulate in shape, and basal, while the unbranched stems are greenish-red in color, and sparingly hairy. Leaves are often lightly glandular (sticky).
Flowerheads are comparatively large, up to 2 inches across, with between 50 and 130 light pink or bluish ray florets and a center of yellow disc florets. Rays are overlapping, and somewhat wider than those of many other erigeron species. The green or purplish phyllaries have quite a dense covering of thick, shaggy, flattened hairs, usually colored white, sometimes purple.